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  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

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  7.       ffmpeg Documentation

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  15.       <h1>

  16.       ffmpeg Documentation

  17.       </h1>

  18. <div align="center">

  19. </div>

  20. 

  21. 

  22. <a name="SEC_Top"></a>

  23. 

  24. <div class="Contents_element" id="SEC_Contents">

  25. <h2 class="contents-heading">Table of Contents</h2>

  26. 

  27. <div class="contents">

  28. 

  29. <ul class="no-bullet">

  30.   <li><a id="toc-Synopsis" href="#Synopsis">1 Synopsis</a></li>

  31.   <li><a id="toc-Description" href="#Description">2 Description</a></li>

  32.   <li><a id="toc-Detailed-description" href="#Detailed-description">3 Detailed description</a>

  33.   <ul class="no-bullet">

  34.     <li><a id="toc-Filtering" href="#Filtering">3.1 Filtering</a>

  35.     <ul class="no-bullet">

  36.       <li><a id="toc-Simple-filtergraphs" href="#Simple-filtergraphs">3.1.1 Simple filtergraphs</a></li>

  37.       <li><a id="toc-Complex-filtergraphs" href="#Complex-filtergraphs">3.1.2 Complex filtergraphs</a></li>

  38.     </ul></li>

  39.     <li><a id="toc-Stream-copy" href="#Stream-copy">3.2 Stream copy</a></li>

  40.   </ul></li>

  41.   <li><a id="toc-Stream-selection" href="#Stream-selection">4 Stream selection</a>

  42.   <ul class="no-bullet">

  43.     <li><a id="toc-Description-1" href="#Description-1">4.1 Description</a>

  44.     <ul class="no-bullet">

  45.       <li><a id="toc-Automatic-stream-selection" href="#Automatic-stream-selection">4.1.1 Automatic stream selection</a></li>

  46.       <li><a id="toc-Manual-stream-selection" href="#Manual-stream-selection">4.1.2 Manual stream selection</a></li>

  47.       <li><a id="toc-Complex-filtergraphs-1" href="#Complex-filtergraphs-1">4.1.3 Complex filtergraphs</a></li>

  48.       <li><a id="toc-Stream-handling" href="#Stream-handling">4.1.4 Stream handling</a></li>

  49.     </ul></li>

  50.     <li><a id="toc-Examples" href="#Examples">4.2 Examples</a></li>

  51.   </ul></li>

  52.   <li><a id="toc-Options" href="#Options">5 Options</a>

  53.   <ul class="no-bullet">

  54.     <li><a id="toc-Stream-specifiers-1" href="#Stream-specifiers-1">5.1 Stream specifiers</a></li>

  55.     <li><a id="toc-Generic-options" href="#Generic-options">5.2 Generic options</a></li>

  56.     <li><a id="toc-AVOptions" href="#AVOptions">5.3 AVOptions</a></li>

  57.     <li><a id="toc-Main-options" href="#Main-options">5.4 Main options</a></li>

  58.     <li><a id="toc-Video-Options" href="#Video-Options">5.5 Video Options</a></li>

  59.     <li><a id="toc-Advanced-Video-options" href="#Advanced-Video-options">5.6 Advanced Video options</a></li>

  60.     <li><a id="toc-Audio-Options" href="#Audio-Options">5.7 Audio Options</a></li>

  61.     <li><a id="toc-Advanced-Audio-options" href="#Advanced-Audio-options">5.8 Advanced Audio options</a></li>

  62.     <li><a id="toc-Subtitle-options" href="#Subtitle-options">5.9 Subtitle options</a></li>

  63.     <li><a id="toc-Advanced-Subtitle-options" href="#Advanced-Subtitle-options">5.10 Advanced Subtitle options</a></li>

  64.     <li><a id="toc-Advanced-options" href="#Advanced-options">5.11 Advanced options</a></li>

  65.     <li><a id="toc-Preset-files" href="#Preset-files">5.12 Preset files</a>

  66.     <ul class="no-bullet">

  67.       <li><a id="toc-ffpreset-files" href="#ffpreset-files">5.12.1 ffpreset files</a></li>

  68.       <li><a id="toc-avpreset-files" href="#avpreset-files">5.12.2 avpreset files</a></li>

  69.     </ul></li>

  70.   </ul></li>

  71.   <li><a id="toc-Examples-1" href="#Examples-1">6 Examples</a>

  72.   <ul class="no-bullet">

  73.     <li><a id="toc-Video-and-Audio-grabbing" href="#Video-and-Audio-grabbing">6.1 Video and Audio grabbing</a></li>

  74.     <li><a id="toc-X11-grabbing" href="#X11-grabbing">6.2 X11 grabbing</a></li>

  75.     <li><a id="toc-Video-and-Audio-file-format-conversion" href="#Video-and-Audio-file-format-conversion">6.3 Video and Audio file format conversion</a></li>

  76.   </ul></li>

  77.   <li><a id="toc-See-Also" href="#See-Also">7 See Also</a></li>

  78.   <li><a id="toc-Authors" href="#Authors">8 Authors</a></li>

  79. </ul>

  80. </div>

  81. </div>

  82. 

  83. <a name="Synopsis"></a>

  84. <h2 class="chapter">1 Synopsis<span class="pull-right"><a class="anchor hidden-xs" href="#Synopsis" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Synopsis" aria-hidden="true">TOC</a></span></h2>

  85. 

  86. <p>ffmpeg [<var>global_options</var>] {[<var>input_file_options</var>] -i <samp>input_url</samp>} ... {[<var>output_file_options</var>] <samp>output_url</samp>} ...

  87. </p>

  88. <a name="Description"></a>

  89. <h2 class="chapter">2 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description" aria-hidden="true">TOC</a></span></h2>

  90. 

  91. <p><code>ffmpeg</code> is a very fast video and audio converter that can also grab from

  92. a live audio/video source. It can also convert between arbitrary sample

  93. rates and resize video on the fly with a high quality polyphase filter.

  94. </p>

  95. <p><code>ffmpeg</code> reads from an arbitrary number of input &quot;files&quot; (which can be regular

  96. files, pipes, network streams, grabbing devices, etc.), specified by the

  97. <code>-i</code> option, and writes to an arbitrary number of output &quot;files&quot;, which are

  98. specified by a plain output url. Anything found on the command line which

  99. cannot be interpreted as an option is considered to be an output url.

  100. </p>

  101. <p>Each input or output url can, in principle, contain any number of streams of

  102. different types (video/audio/subtitle/attachment/data). The allowed number and/or

  103. types of streams may be limited by the container format. Selecting which

  104. streams from which inputs will go into which output is either done automatically

  105. or with the <code>-map</code> option (see the Stream selection chapter).

  106. </p>

  107. <p>To refer to input files in options, you must use their indices (0-based). E.g.

  108. the first input file is <code>0</code>, the second is <code>1</code>, etc. Similarly, streams

  109. within a file are referred to by their indices. E.g. <code>2:3</code> refers to the

  110. fourth stream in the third input file. Also see the Stream specifiers chapter.

  111. </p>

  112. <p>As a general rule, options are applied to the next specified

  113. file. Therefore, order is important, and you can have the same

  114. option on the command line multiple times. Each occurrence is

  115. then applied to the next input or output file.

  116. Exceptions from this rule are the global options (e.g. verbosity level),

  117. which should be specified first.

  118. </p>

  119. <p>Do not mix input and output files &ndash; first specify all input files, then all

  120. output files. Also do not mix options which belong to different files. All

  121. options apply ONLY to the next input or output file and are reset between files.

  122. </p>

  123. <ul>

  124. <li> To set the video bitrate of the output file to 64 kbit/s:

  125. <div class="example">

  126. <pre class="example">ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi

  127. </pre></div>

  128. 

  129. </li><li> To force the frame rate of the output file to 24 fps:

  130. <div class="example">

  131. <pre class="example">ffmpeg -i input.avi -r 24 output.avi

  132. </pre></div>

  133. 

  134. </li><li> To force the frame rate of the input file (valid for raw formats only)

  135. to 1 fps and the frame rate of the output file to 24 fps:

  136. <div class="example">

  137. <pre class="example">ffmpeg -r 1 -i input.m2v -r 24 output.avi

  138. </pre></div>

  139. </li></ul>

  140. 

  141. <p>The format option may be needed for raw input files.

  142. </p>

  143. 

  144. <a name="Detailed-description"></a>

  145. <h2 class="chapter">3 Detailed description<span class="pull-right"><a class="anchor hidden-xs" href="#Detailed-description" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Detailed-description" aria-hidden="true">TOC</a></span></h2>

  146. 

  147. <p>The transcoding process in <code>ffmpeg</code> for each output can be described by

  148. the following diagram:

  149. </p>

  150. <pre class="verbatim"> _______              ______________

  151. |       |            |              |

  152. | input |  demuxer   | encoded data |   decoder

  153. | file  | ---------&gt; | packets      | -----+

  154. |_______|            |______________|      |

  155.                                            v

  156.                                        _________

  157.                                       |         |

  158.                                       | decoded |

  159.                                       | frames  |

  160.                                       |_________|

  161.  ________             ______________       |

  162. |        |           |              |      |

  163. | output | &lt;-------- | encoded data | &lt;----+

  164. | file   |   muxer   | packets      |   encoder

  165. |________|           |______________|

  166. 

  167. 

  168. </pre>

  169. <p><code>ffmpeg</code> calls the libavformat library (containing demuxers) to read

  170. input files and get packets containing encoded data from them. When there are

  171. multiple input files, <code>ffmpeg</code> tries to keep them synchronized by

  172. tracking lowest timestamp on any active input stream.

  173. </p>

  174. <p>Encoded packets are then passed to the decoder (unless streamcopy is selected

  175. for the stream, see further for a description). The decoder produces

  176. uncompressed frames (raw video/PCM audio/...) which can be processed further by

  177. filtering (see next section). After filtering, the frames are passed to the

  178. encoder, which encodes them and outputs encoded packets. Finally those are

  179. passed to the muxer, which writes the encoded packets to the output file.

  180. </p>

  181. <a name="Filtering"></a>

  182. <h3 class="section">3.1 Filtering<span class="pull-right"><a class="anchor hidden-xs" href="#Filtering" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Filtering" aria-hidden="true">TOC</a></span></h3>

  183. <p>Before encoding, <code>ffmpeg</code> can process raw audio and video frames using

  184. filters from the libavfilter library. Several chained filters form a filter

  185. graph. <code>ffmpeg</code> distinguishes between two types of filtergraphs:

  186. simple and complex.

  187. </p>

  188. <a name="Simple-filtergraphs"></a>

  189. <h4 class="subsection">3.1.1 Simple filtergraphs<span class="pull-right"><a class="anchor hidden-xs" href="#Simple-filtergraphs" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Simple-filtergraphs" aria-hidden="true">TOC</a></span></h4>

  190. <p>Simple filtergraphs are those that have exactly one input and output, both of

  191. the same type. In the above diagram they can be represented by simply inserting

  192. an additional step between decoding and encoding:

  193. </p>

  194. <pre class="verbatim"> _________                        ______________

  195. |         |                      |              |

  196. | decoded |                      | encoded data |

  197. | frames  |\                   _ | packets      |

  198. |_________| \                  /||______________|

  199.              \   __________   /

  200.   simple     _\||          | /  encoder

  201.   filtergraph   | filtered |/

  202.                 | frames   |

  203.                 |__________|

  204. 

  205. </pre>

  206. <p>Simple filtergraphs are configured with the per-stream <samp>-filter</samp> option

  207. (with <samp>-vf</samp> and <samp>-af</samp> aliases for video and audio respectively).

  208. A simple filtergraph for video can look for example like this:

  209. </p>

  210. <pre class="verbatim"> _______        _____________        _______        ________

  211. |       |      |             |      |       |      |        |

  212. | input | ---&gt; | deinterlace | ---&gt; | scale | ---&gt; | output |

  213. |_______|      |_____________|      |_______|      |________|

  214. 

  215. </pre>

  216. <p>Note that some filters change frame properties but not frame contents. E.g. the

  217. <code>fps</code> filter in the example above changes number of frames, but does not

  218. touch the frame contents. Another example is the <code>setpts</code> filter, which

  219. only sets timestamps and otherwise passes the frames unchanged.

  220. </p>

  221. <a name="Complex-filtergraphs"></a>

  222. <h4 class="subsection">3.1.2 Complex filtergraphs<span class="pull-right"><a class="anchor hidden-xs" href="#Complex-filtergraphs" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Complex-filtergraphs" aria-hidden="true">TOC</a></span></h4>

  223. <p>Complex filtergraphs are those which cannot be described as simply a linear

  224. processing chain applied to one stream. This is the case, for example, when the graph has

  225. more than one input and/or output, or when output stream type is different from

  226. input. They can be represented with the following diagram:

  227. </p>

  228. <pre class="verbatim"> _________

  229. |         |

  230. | input 0 |\                    __________

  231. |_________| \                  |          |

  232.              \   _________    /| output 0 |

  233.               \ |         |  / |__________|

  234.  _________     \| complex | /

  235. |         |     |         |/

  236. | input 1 |----&gt;| filter  |\

  237. |_________|     |         | \   __________

  238.                /| graph   |  \ |          |

  239.               / |         |   \| output 1 |

  240.  _________   /  |_________|    |__________|

  241. |         | /

  242. | input 2 |/

  243. |_________|

  244. 

  245. </pre>

  246. <p>Complex filtergraphs are configured with the <samp>-filter_complex</samp> option.

  247. Note that this option is global, since a complex filtergraph, by its nature,

  248. cannot be unambiguously associated with a single stream or file.

  249. </p>

  250. <p>The <samp>-lavfi</samp> option is equivalent to <samp>-filter_complex</samp>.

  251. </p>

  252. <p>A trivial example of a complex filtergraph is the <code>overlay</code> filter, which

  253. has two video inputs and one video output, containing one video overlaid on top

  254. of the other. Its audio counterpart is the <code>amix</code> filter.

  255. </p>

  256. <a name="Stream-copy"></a>

  257. <h3 class="section">3.2 Stream copy<span class="pull-right"><a class="anchor hidden-xs" href="#Stream-copy" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Stream-copy" aria-hidden="true">TOC</a></span></h3>

  258. <p>Stream copy is a mode selected by supplying the <code>copy</code> parameter to the

  259. <samp>-codec</samp> option. It makes <code>ffmpeg</code> omit the decoding and encoding

  260. step for the specified stream, so it does only demuxing and muxing. It is useful

  261. for changing the container format or modifying container-level metadata. The

  262. diagram above will, in this case, simplify to this:

  263. </p>

  264. <pre class="verbatim"> _______              ______________            ________

  265. |       |            |              |          |        |

  266. | input |  demuxer   | encoded data |  muxer   | output |

  267. | file  | ---------&gt; | packets      | -------&gt; | file   |

  268. |_______|            |______________|          |________|

  269. 

  270. </pre>

  271. <p>Since there is no decoding or encoding, it is very fast and there is no quality

  272. loss. However, it might not work in some cases because of many factors. Applying

  273. filters is obviously also impossible, since filters work on uncompressed data.

  274. </p>

  275. 

  276. <a name="Stream-selection"></a>

  277. <h2 class="chapter">4 Stream selection<span class="pull-right"><a class="anchor hidden-xs" href="#Stream-selection" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Stream-selection" aria-hidden="true">TOC</a></span></h2>

  278. 

  279. <p><code>ffmpeg</code> provides the <code>-map</code> option for manual control of stream selection in each

  280. output file. Users can skip <code>-map</code> and let ffmpeg perform automatic stream selection as

  281. described below. The <code>-vn / -an / -sn / -dn</code> options can be used to skip inclusion of

  282. video, audio, subtitle and data streams respectively, whether manually mapped or automatically

  283. selected, except for those streams which are outputs of complex filtergraphs.

  284. </p>

  285. <a name="Description-1"></a>

  286. <h3 class="section">4.1 Description<span class="pull-right"><a class="anchor hidden-xs" href="#Description-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Description-1" aria-hidden="true">TOC</a></span></h3>

  287. <p>The sub-sections that follow describe the various rules that are involved in stream selection.

  288. The examples that follow next show how these rules are applied in practice.

  289. </p>

  290. <p>While every effort is made to accurately reflect the behavior of the program, FFmpeg is under

  291. continuous development and the code may have changed since the time of this writing.

  292. </p>

  293. <a name="Automatic-stream-selection"></a>

  294. <h4 class="subsection">4.1.1 Automatic stream selection<span class="pull-right"><a class="anchor hidden-xs" href="#Automatic-stream-selection" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Automatic-stream-selection" aria-hidden="true">TOC</a></span></h4>

  295. 

  296. <p>In the absence of any map options for a particular output file, ffmpeg inspects the output

  297. format to check which type of streams can be included in it, viz. video, audio and/or

  298. subtitles. For each acceptable stream type, ffmpeg will pick one stream, when available,

  299. from among all the inputs.

  300. </p>

  301. <p>It will select that stream based upon the following criteria:

  302. </p><ul>

  303. <li> for video, it is the stream with the highest resolution,

  304. </li><li> for audio, it is the stream with the most channels,

  305. </li><li> for subtitles, it is the first subtitle stream found but there&rsquo;s a caveat.

  306. The output format&rsquo;s default subtitle encoder can be either text-based or image-based,

  307. and only a subtitle stream of the same type will be chosen.

  308. </li></ul>

  309. 

  310. <p>In the case where several streams of the same type rate equally, the stream with the lowest

  311. index is chosen.

  312. </p>

  313. <p>Data or attachment streams are not automatically selected and can only be included

  314. using <code>-map</code>.

  315. </p><a name="Manual-stream-selection"></a>

  316. <h4 class="subsection">4.1.2 Manual stream selection<span class="pull-right"><a class="anchor hidden-xs" href="#Manual-stream-selection" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Manual-stream-selection" aria-hidden="true">TOC</a></span></h4>

  317. 

  318. <p>When <code>-map</code> is used, only user-mapped streams are included in that output file,

  319. with one possible exception for filtergraph outputs described below.

  320. </p>

  321. <a name="Complex-filtergraphs-1"></a>

  322. <h4 class="subsection">4.1.3 Complex filtergraphs<span class="pull-right"><a class="anchor hidden-xs" href="#Complex-filtergraphs-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Complex-filtergraphs-1" aria-hidden="true">TOC</a></span></h4>

  323. 

  324. <p>If there are any complex filtergraph output streams with unlabeled pads, they will be added

  325. to the first output file. This will lead to a fatal error if the stream type is not supported

  326. by the output format. In the absence of the map option, the inclusion of these streams leads

  327. to the automatic stream selection of their types being skipped. If map options are present,

  328. these filtergraph streams are included in addition to the mapped streams.

  329. </p>

  330. <p>Complex filtergraph output streams with labeled pads must be mapped once and exactly once.

  331. </p>

  332. <a name="Stream-handling"></a>

  333. <h4 class="subsection">4.1.4 Stream handling<span class="pull-right"><a class="anchor hidden-xs" href="#Stream-handling" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Stream-handling" aria-hidden="true">TOC</a></span></h4>

  334. 

  335. <p>Stream handling is independent of stream selection, with an exception for subtitles described

  336. below. Stream handling is set via the <code>-codec</code> option addressed to streams within a

  337. specific <em>output</em> file. In particular, codec options are applied by ffmpeg after the

  338. stream selection process and thus do not influence the latter. If no <code>-codec</code> option is

  339. specified for a stream type, ffmpeg will select the default encoder registered by the output

  340. file muxer.

  341. </p>

  342. <p>An exception exists for subtitles. If a subtitle encoder is specified for an output file, the

  343. first subtitle stream found of any type, text or image, will be included. ffmpeg does not validate

  344. if the specified encoder can convert the selected stream or if the converted stream is acceptable

  345. within the output format. This applies generally as well: when the user sets an encoder manually,

  346. the stream selection process cannot check if the encoded stream can be muxed into the output file.

  347. If it cannot, ffmpeg will abort and <em>all</em> output files will fail to be processed.

  348. </p>

  349. <a name="Examples"></a>

  350. <h3 class="section">4.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples" aria-hidden="true">TOC</a></span></h3>

  351. 

  352. <p>The following examples illustrate the behavior, quirks and limitations of ffmpeg&rsquo;s stream

  353. selection methods.

  354. </p>

  355. <p>They assume the following three input files.

  356. </p>

  357. <pre class="verbatim">

  358. input file 'A.avi'

  359.       stream 0: video 640x360

  360.       stream 1: audio 2 channels

  361. 

  362. input file 'B.mp4'

  363.       stream 0: video 1920x1080

  364.       stream 1: audio 2 channels

  365.       stream 2: subtitles (text)

  366.       stream 3: audio 5.1 channels

  367.       stream 4: subtitles (text)

  368. 

  369. input file 'C.mkv'

  370.       stream 0: video 1280x720

  371.       stream 1: audio 2 channels

  372.       stream 2: subtitles (image)

  373. </pre>

  374. <a name="Example_003a-automatic-stream-selection"></a>

  375. <div class="example">

  376. <pre class="example">ffmpeg -i A.avi -i B.mp4 out1.mkv out2.wav -map 1:a -c:a copy out3.mov

  377. </pre></div>

  378. <p>There are three output files specified, and for the first two, no <code>-map</code> options

  379. are set, so ffmpeg will select streams for these two files automatically.

  380. </p>

  381. <p><samp>out1.mkv</samp> is a Matroska container file and accepts video, audio and subtitle streams,

  382. so ffmpeg will try to select one of each type.<br>

  383. For video, it will select <code>stream 0</code> from <samp>B.mp4</samp>, which has the highest

  384. resolution among all the input video streams.<br>

  385. For audio, it will select <code>stream 3</code> from <samp>B.mp4</samp>, since it has the greatest

  386. number of channels.<br>

  387. For subtitles, it will select <code>stream 2</code> from <samp>B.mp4</samp>, which is the first subtitle

  388. stream from among <samp>A.avi</samp> and <samp>B.mp4</samp>.

  389. </p>

  390. <p><samp>out2.wav</samp> accepts only audio streams, so only <code>stream 3</code> from <samp>B.mp4</samp> is

  391. selected.

  392. </p>

  393. <p>For <samp>out3.mov</samp>, since a <code>-map</code> option is set, no automatic stream selection will

  394. occur. The <code>-map 1:a</code> option will select all audio streams from the second input

  395. <samp>B.mp4</samp>. No other streams will be included in this output file.

  396. </p>

  397. <p>For the first two outputs, all included streams will be transcoded. The encoders chosen will

  398. be the default ones registered by each output format, which may not match the codec of the

  399. selected input streams.

  400. </p>

  401. <p>For the third output, codec option for audio streams has been set

  402. to <code>copy</code>, so no decoding-filtering-encoding operations will occur, or <em>can</em> occur.

  403. Packets of selected streams shall be conveyed from the input file and muxed within the output

  404. file.

  405. </p>

  406. <a name="Example_003a-automatic-subtitles-selection"></a>

  407. <div class="example">

  408. <pre class="example">ffmpeg -i C.mkv out1.mkv -c:s dvdsub -an out2.mkv

  409. </pre></div>

  410. <p>Although <samp>out1.mkv</samp> is a Matroska container file which accepts subtitle streams, only a

  411. video and audio stream shall be selected. The subtitle stream of <samp>C.mkv</samp> is image-based

  412. and the default subtitle encoder of the Matroska muxer is text-based, so a transcode operation

  413. for the subtitles is expected to fail and hence the stream isn&rsquo;t selected. However, in

  414. <samp>out2.mkv</samp>, a subtitle encoder is specified in the command and so, the subtitle stream is

  415. selected, in addition to the video stream. The presence of <code>-an</code> disables audio stream

  416. selection for <samp>out2.mkv</samp>.

  417. </p>

  418. <a name="Example_003a-unlabeled-filtergraph-outputs"></a>

  419. <div class="example">

  420. <pre class="example">ffmpeg -i A.avi -i C.mkv -i B.mp4 -filter_complex &quot;overlay&quot; out1.mp4 out2.srt

  421. </pre></div>

  422. <p>A filtergraph is setup here using the <code>-filter_complex</code> option and consists of a single

  423. video filter. The <code>overlay</code> filter requires exactly two video inputs, but none are

  424. specified, so the first two available video streams are used, those of <samp>A.avi</samp> and

  425. <samp>C.mkv</samp>. The output pad of the filter has no label and so is sent to the first output file

  426. <samp>out1.mp4</samp>. Due to this, automatic selection of the video stream is skipped, which would

  427. have selected the stream in <samp>B.mp4</samp>. The audio stream with most channels viz. <code>stream 3</code>

  428. in <samp>B.mp4</samp>, is chosen automatically. No subtitle stream is chosen however, since the MP4

  429. format has no default subtitle encoder registered, and the user hasn&rsquo;t specified a subtitle encoder.

  430. </p>

  431. <p>The 2nd output file, <samp>out2.srt</samp>, only accepts text-based subtitle streams. So, even though

  432. the first subtitle stream available belongs to <samp>C.mkv</samp>, it is image-based and hence skipped.

  433. The selected stream, <code>stream 2</code> in <samp>B.mp4</samp>, is the first text-based subtitle stream.

  434. </p>

  435. <a name="Example_003a-labeled-filtergraph-outputs"></a>

  436. <div class="example">

  437. <pre class="example">ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex &quot;[1:v]hue=s=0[outv];overlay;aresample&quot; \

  438.        -map '[outv]' -an        out1.mp4 \

  439.                                 out2.mkv \

  440.        -map '[outv]' -map 1:a:0 out3.mkv

  441. </pre></div>

  442. 

  443. <p>The above command will fail, as the output pad labelled <code>[outv]</code> has been mapped twice.

  444. None of the output files shall be processed.

  445. </p>

  446. <div class="example">

  447. <pre class="example">ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex &quot;[1:v]hue=s=0[outv];overlay;aresample&quot; \

  448.        -an        out1.mp4 \

  449.                   out2.mkv \

  450.        -map 1:a:0 out3.mkv

  451. </pre></div>

  452. 

  453. <p>This command above will also fail as the hue filter output has a label, <code>[outv]</code>,

  454. and hasn&rsquo;t been mapped anywhere.

  455. </p>

  456. <p>The command should be modified as follows,

  457. </p><div class="example">

  458. <pre class="example">ffmpeg -i A.avi -i B.mp4 -i C.mkv -filter_complex &quot;[1:v]hue=s=0,split=2[outv1][outv2];overlay;aresample&quot; \

  459.         -map '[outv1]' -an        out1.mp4 \

  460.                                   out2.mkv \

  461.         -map '[outv2]' -map 1:a:0 out3.mkv

  462. </pre></div>

  463. <p>The video stream from <samp>B.mp4</samp> is sent to the hue filter, whose output is cloned once using

  464. the split filter, and both outputs labelled. Then a copy each is mapped to the first and third

  465. output files.

  466. </p>

  467. <p>The overlay filter, requiring two video inputs, uses the first two unused video streams. Those

  468. are the streams from <samp>A.avi</samp> and <samp>C.mkv</samp>. The overlay output isn&rsquo;t labelled, so it is

  469. sent to the first output file <samp>out1.mp4</samp>, regardless of the presence of the <code>-map</code> option.

  470. </p>

  471. <p>The aresample filter is sent the first unused audio stream, that of <samp>A.avi</samp>. Since this filter

  472. output is also unlabelled, it too is mapped to the first output file. The presence of <code>-an</code>

  473. only suppresses automatic or manual stream selection of audio streams, not outputs sent from

  474. filtergraphs. Both these mapped streams shall be ordered before the mapped stream in <samp>out1.mp4</samp>.

  475. </p>

  476. <p>The video, audio and subtitle streams mapped to <code>out2.mkv</code> are entirely determined by

  477. automatic stream selection.

  478. </p>

  479. <p><samp>out3.mkv</samp> consists of the cloned video output from the hue filter and the first audio

  480. stream from <samp>B.mp4</samp>.

  481. <br>

  482. </p>

  483. 

  484. <a name="Options"></a>

  485. <h2 class="chapter">5 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options" aria-hidden="true">TOC</a></span></h2>

  486. 

  487. <p>All the numerical options, if not specified otherwise, accept a string

  488. representing a number as input, which may be followed by one of the SI

  489. unit prefixes, for example: &rsquo;K&rsquo;, &rsquo;M&rsquo;, or &rsquo;G&rsquo;.

  490. </p>

  491. <p>If &rsquo;i&rsquo; is appended to the SI unit prefix, the complete prefix will be

  492. interpreted as a unit prefix for binary multiples, which are based on

  493. powers of 1024 instead of powers of 1000. Appending &rsquo;B&rsquo; to the SI unit

  494. prefix multiplies the value by 8. This allows using, for example:

  495. &rsquo;KB&rsquo;, &rsquo;MiB&rsquo;, &rsquo;G&rsquo; and &rsquo;B&rsquo; as number suffixes.

  496. </p>

  497. <p>Options which do not take arguments are boolean options, and set the

  498. corresponding value to true. They can be set to false by prefixing

  499. the option name with &quot;no&quot;. For example using &quot;-nofoo&quot;

  500. will set the boolean option with name &quot;foo&quot; to false.

  501. </p>

  502. <span id="Stream-specifiers"></span><a name="Stream-specifiers-1"></a>

  503. <h3 class="section">5.1 Stream specifiers<span class="pull-right"><a class="anchor hidden-xs" href="#Stream-specifiers-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Stream-specifiers-1" aria-hidden="true">TOC</a></span></h3>

  504. <p>Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers

  505. are used to precisely specify which stream(s) a given option belongs to.

  506. </p>

  507. <p>A stream specifier is a string generally appended to the option name and

  508. separated from it by a colon. E.g. <code>-codec:a:1 ac3</code> contains the

  509. <code>a:1</code> stream specifier, which matches the second audio stream. Therefore, it

  510. would select the ac3 codec for the second audio stream.

  511. </p>

  512. <p>A stream specifier can match several streams, so that the option is applied to all

  513. of them. E.g. the stream specifier in <code>-b:a 128k</code> matches all audio

  514. streams.

  515. </p>

  516. <p>An empty stream specifier matches all streams. For example, <code>-codec copy</code>

  517. or <code>-codec: copy</code> would copy all the streams without reencoding.

  518. </p>

  519. <p>Possible forms of stream specifiers are:

  520. </p><dl compact="compact">

  521. <dt><span><samp><var>stream_index</var></samp></span></dt>

  522. <dd><p>Matches the stream with this index. E.g. <code>-threads:1 4</code> would set the

  523. thread count for the second stream to 4. If <var>stream_index</var> is used as an

  524. additional stream specifier (see below), then it selects stream number

  525. <var>stream_index</var> from the matching streams. Stream numbering is based on the

  526. order of the streams as detected by libavformat except when a program ID is

  527. also specified. In this case it is based on the ordering of the streams in the

  528. program.

  529. </p></dd>

  530. <dt><span><samp><var>stream_type</var>[:<var>additional_stream_specifier</var>]</samp></span></dt>

  531. <dd><p><var>stream_type</var> is one of following: &rsquo;v&rsquo; or &rsquo;V&rsquo; for video, &rsquo;a&rsquo; for audio, &rsquo;s&rsquo;

  532. for subtitle, &rsquo;d&rsquo; for data, and &rsquo;t&rsquo; for attachments. &rsquo;v&rsquo; matches all video

  533. streams, &rsquo;V&rsquo; only matches video streams which are not attached pictures, video

  534. thumbnails or cover arts. If <var>additional_stream_specifier</var> is used, then

  535. it matches streams which both have this type and match the

  536. <var>additional_stream_specifier</var>. Otherwise, it matches all streams of the

  537. specified type.

  538. </p></dd>

  539. <dt><span><samp>p:<var>program_id</var>[:<var>additional_stream_specifier</var>]</samp></span></dt>

  540. <dd><p>Matches streams which are in the program with the id <var>program_id</var>. If

  541. <var>additional_stream_specifier</var> is used, then it matches streams which both

  542. are part of the program and match the <var>additional_stream_specifier</var>.

  543. </p>

  544. </dd>

  545. <dt><span><samp>#<var>stream_id</var> or i:<var>stream_id</var></samp></span></dt>

  546. <dd><p>Match the stream by stream id (e.g. PID in MPEG-TS container).

  547. </p></dd>

  548. <dt><span><samp>m:<var>key</var>[:<var>value</var>]</samp></span></dt>

  549. <dd><p>Matches streams with the metadata tag <var>key</var> having the specified value. If

  550. <var>value</var> is not given, matches streams that contain the given tag with any

  551. value.

  552. </p></dd>

  553. <dt><span><samp>u</samp></span></dt>

  554. <dd><p>Matches streams with usable configuration, the codec must be defined and the

  555. essential information such as video dimension or audio sample rate must be present.

  556. </p>

  557. <p>Note that in <code>ffmpeg</code>, matching by metadata will only work properly for

  558. input files.

  559. </p></dd>

  560. </dl>

  561. 

  562. <a name="Generic-options"></a>

  563. <h3 class="section">5.2 Generic options<span class="pull-right"><a class="anchor hidden-xs" href="#Generic-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Generic-options" aria-hidden="true">TOC</a></span></h3>

  564. 

  565. <p>These options are shared amongst the ff* tools.

  566. </p>

  567. <dl compact="compact">

  568. <dt><span><samp>-L</samp></span></dt>

  569. <dd><p>Show license.

  570. </p>

  571. </dd>

  572. <dt><span><samp>-h, -?, -help, --help [<var>arg</var>]</samp></span></dt>

  573. <dd><p>Show help. An optional parameter may be specified to print help about a specific

  574. item. If no argument is specified, only basic (non advanced) tool

  575. options are shown.

  576. </p>

  577. <p>Possible values of <var>arg</var> are:

  578. </p><dl compact="compact">

  579. <dt><span><samp>long</samp></span></dt>

  580. <dd><p>Print advanced tool options in addition to the basic tool options.

  581. </p>

  582. </dd>

  583. <dt><span><samp>full</samp></span></dt>

  584. <dd><p>Print complete list of options, including shared and private options

  585. for encoders, decoders, demuxers, muxers, filters, etc.

  586. </p>

  587. </dd>

  588. <dt><span><samp>decoder=<var>decoder_name</var></samp></span></dt>

  589. <dd><p>Print detailed information about the decoder named <var>decoder_name</var>. Use the

  590. <samp>-decoders</samp> option to get a list of all decoders.

  591. </p>

  592. </dd>

  593. <dt><span><samp>encoder=<var>encoder_name</var></samp></span></dt>

  594. <dd><p>Print detailed information about the encoder named <var>encoder_name</var>. Use the

  595. <samp>-encoders</samp> option to get a list of all encoders.

  596. </p>

  597. </dd>

  598. <dt><span><samp>demuxer=<var>demuxer_name</var></samp></span></dt>

  599. <dd><p>Print detailed information about the demuxer named <var>demuxer_name</var>. Use the

  600. <samp>-formats</samp> option to get a list of all demuxers and muxers.

  601. </p>

  602. </dd>

  603. <dt><span><samp>muxer=<var>muxer_name</var></samp></span></dt>

  604. <dd><p>Print detailed information about the muxer named <var>muxer_name</var>. Use the

  605. <samp>-formats</samp> option to get a list of all muxers and demuxers.

  606. </p>

  607. </dd>

  608. <dt><span><samp>filter=<var>filter_name</var></samp></span></dt>

  609. <dd><p>Print detailed information about the filter named <var>filter_name</var>. Use the

  610. <samp>-filters</samp> option to get a list of all filters.

  611. </p>

  612. </dd>

  613. <dt><span><samp>bsf=<var>bitstream_filter_name</var></samp></span></dt>

  614. <dd><p>Print detailed information about the bitstream filter named <var>bitstream_filter_name</var>.

  615. Use the <samp>-bsfs</samp> option to get a list of all bitstream filters.

  616. </p>

  617. </dd>

  618. <dt><span><samp>protocol=<var>protocol_name</var></samp></span></dt>

  619. <dd><p>Print detailed information about the protocol named <var>protocol_name</var>.

  620. Use the <samp>-protocols</samp> option to get a list of all protocols.

  621. </p></dd>

  622. </dl>

  623. 

  624. </dd>

  625. <dt><span><samp>-version</samp></span></dt>

  626. <dd><p>Show version.

  627. </p>

  628. </dd>

  629. <dt><span><samp>-buildconf</samp></span></dt>

  630. <dd><p>Show the build configuration, one option per line.

  631. </p>

  632. </dd>

  633. <dt><span><samp>-formats</samp></span></dt>

  634. <dd><p>Show available formats (including devices).

  635. </p>

  636. </dd>

  637. <dt><span><samp>-demuxers</samp></span></dt>

  638. <dd><p>Show available demuxers.

  639. </p>

  640. </dd>

  641. <dt><span><samp>-muxers</samp></span></dt>

  642. <dd><p>Show available muxers.

  643. </p>

  644. </dd>

  645. <dt><span><samp>-devices</samp></span></dt>

  646. <dd><p>Show available devices.

  647. </p>

  648. </dd>

  649. <dt><span><samp>-codecs</samp></span></dt>

  650. <dd><p>Show all codecs known to libavcodec.

  651. </p>

  652. <p>Note that the term &rsquo;codec&rsquo; is used throughout this documentation as a shortcut

  653. for what is more correctly called a media bitstream format.

  654. </p>

  655. </dd>

  656. <dt><span><samp>-decoders</samp></span></dt>

  657. <dd><p>Show available decoders.

  658. </p>

  659. </dd>

  660. <dt><span><samp>-encoders</samp></span></dt>

  661. <dd><p>Show all available encoders.

  662. </p>

  663. </dd>

  664. <dt><span><samp>-bsfs</samp></span></dt>

  665. <dd><p>Show available bitstream filters.

  666. </p>

  667. </dd>

  668. <dt><span><samp>-protocols</samp></span></dt>

  669. <dd><p>Show available protocols.

  670. </p>

  671. </dd>

  672. <dt><span><samp>-filters</samp></span></dt>

  673. <dd><p>Show available libavfilter filters.

  674. </p>

  675. </dd>

  676. <dt><span><samp>-pix_fmts</samp></span></dt>

  677. <dd><p>Show available pixel formats.

  678. </p>

  679. </dd>

  680. <dt><span><samp>-sample_fmts</samp></span></dt>

  681. <dd><p>Show available sample formats.

  682. </p>

  683. </dd>

  684. <dt><span><samp>-layouts</samp></span></dt>

  685. <dd><p>Show channel names and standard channel layouts.

  686. </p>

  687. </dd>

  688. <dt><span><samp>-dispositions</samp></span></dt>

  689. <dd><p>Show stream dispositions.

  690. </p>

  691. </dd>

  692. <dt><span><samp>-colors</samp></span></dt>

  693. <dd><p>Show recognized color names.

  694. </p>

  695. </dd>

  696. <dt><span><samp>-sources <var>device</var>[,<var>opt1</var>=<var>val1</var>[,<var>opt2</var>=<var>val2</var>]...]</samp></span></dt>

  697. <dd><p>Show autodetected sources of the input device.

  698. Some devices may provide system-dependent source names that cannot be autodetected.

  699. The returned list cannot be assumed to be always complete.

  700. </p><div class="example">

  701. <pre class="example">ffmpeg -sources pulse,server=192.168.0.4

  702. </pre></div>

  703. 

  704. </dd>

  705. <dt><span><samp>-sinks <var>device</var>[,<var>opt1</var>=<var>val1</var>[,<var>opt2</var>=<var>val2</var>]...]</samp></span></dt>

  706. <dd><p>Show autodetected sinks of the output device.

  707. Some devices may provide system-dependent sink names that cannot be autodetected.

  708. The returned list cannot be assumed to be always complete.

  709. </p><div class="example">

  710. <pre class="example">ffmpeg -sinks pulse,server=192.168.0.4

  711. </pre></div>

  712. 

  713. </dd>

  714. <dt><span><samp>-loglevel [<var>flags</var>+]<var>loglevel</var> | -v [<var>flags</var>+]<var>loglevel</var></samp></span></dt>

  715. <dd><p>Set logging level and flags used by the library.

  716. </p>

  717. <p>The optional <var>flags</var> prefix can consist of the following values:

  718. </p><dl compact="compact">

  719. <dt><span>&lsquo;<samp>repeat</samp>&rsquo;</span></dt>

  720. <dd><p>Indicates that repeated log output should not be compressed to the first line

  721. and the &quot;Last message repeated n times&quot; line will be omitted.

  722. </p></dd>

  723. <dt><span>&lsquo;<samp>level</samp>&rsquo;</span></dt>

  724. <dd><p>Indicates that log output should add a <code>[level]</code> prefix to each message

  725. line. This can be used as an alternative to log coloring, e.g. when dumping the

  726. log to file.

  727. </p></dd>

  728. </dl>

  729. <p>Flags can also be used alone by adding a &rsquo;+&rsquo;/&rsquo;-&rsquo; prefix to set/reset a single

  730. flag without affecting other <var>flags</var> or changing <var>loglevel</var>. When

  731. setting both <var>flags</var> and <var>loglevel</var>, a &rsquo;+&rsquo; separator is expected

  732. between the last <var>flags</var> value and before <var>loglevel</var>.

  733. </p>

  734. <p><var>loglevel</var> is a string or a number containing one of the following values:

  735. </p><dl compact="compact">

  736. <dt><span>&lsquo;<samp>quiet, -8</samp>&rsquo;</span></dt>

  737. <dd><p>Show nothing at all; be silent.

  738. </p></dd>

  739. <dt><span>&lsquo;<samp>panic, 0</samp>&rsquo;</span></dt>

  740. <dd><p>Only show fatal errors which could lead the process to crash, such as

  741. an assertion failure. This is not currently used for anything.

  742. </p></dd>

  743. <dt><span>&lsquo;<samp>fatal, 8</samp>&rsquo;</span></dt>

  744. <dd><p>Only show fatal errors. These are errors after which the process absolutely

  745. cannot continue.

  746. </p></dd>

  747. <dt><span>&lsquo;<samp>error, 16</samp>&rsquo;</span></dt>

  748. <dd><p>Show all errors, including ones which can be recovered from.

  749. </p></dd>

  750. <dt><span>&lsquo;<samp>warning, 24</samp>&rsquo;</span></dt>

  751. <dd><p>Show all warnings and errors. Any message related to possibly

  752. incorrect or unexpected events will be shown.

  753. </p></dd>

  754. <dt><span>&lsquo;<samp>info, 32</samp>&rsquo;</span></dt>

  755. <dd><p>Show informative messages during processing. This is in addition to

  756. warnings and errors. This is the default value.

  757. </p></dd>

  758. <dt><span>&lsquo;<samp>verbose, 40</samp>&rsquo;</span></dt>

  759. <dd><p>Same as <code>info</code>, except more verbose.

  760. </p></dd>

  761. <dt><span>&lsquo;<samp>debug, 48</samp>&rsquo;</span></dt>

  762. <dd><p>Show everything, including debugging information.

  763. </p></dd>

  764. <dt><span>&lsquo;<samp>trace, 56</samp>&rsquo;</span></dt>

  765. </dl>

  766. 

  767. <p>For example to enable repeated log output, add the <code>level</code> prefix, and set

  768. <var>loglevel</var> to <code>verbose</code>:

  769. </p><div class="example">

  770. <pre class="example">ffmpeg -loglevel repeat+level+verbose -i input output

  771. </pre></div>

  772. <p>Another example that enables repeated log output without affecting current

  773. state of <code>level</code> prefix flag or <var>loglevel</var>:

  774. </p><div class="example">

  775. <pre class="example">ffmpeg [...] -loglevel +repeat

  776. </pre></div>

  777. 

  778. <p>By default the program logs to stderr. If coloring is supported by the

  779. terminal, colors are used to mark errors and warnings. Log coloring

  780. can be disabled setting the environment variable

  781. <code>AV_LOG_FORCE_NOCOLOR</code>, or can be forced setting

  782. the environment variable <code>AV_LOG_FORCE_COLOR</code>.

  783. </p>

  784. </dd>

  785. <dt><span><samp>-report</samp></span></dt>

  786. <dd><p>Dump full command line and log output to a file named

  787. <code><var>program</var>-<var>YYYYMMDD</var>-<var>HHMMSS</var>.log</code> in the current

  788. directory.

  789. This file can be useful for bug reports.

  790. It also implies <code>-loglevel debug</code>.

  791. </p>

  792. <p>Setting the environment variable <code>FFREPORT</code> to any value has the

  793. same effect. If the value is a &rsquo;:&rsquo;-separated key=value sequence, these

  794. options will affect the report; option values must be escaped if they

  795. contain special characters or the options delimiter &rsquo;:&rsquo; (see the

  796. &ldquo;Quoting and escaping&rdquo; section in the ffmpeg-utils manual).

  797. </p>

  798. <p>The following options are recognized:

  799. </p><dl compact="compact">

  800. <dt><span><samp>file</samp></span></dt>

  801. <dd><p>set the file name to use for the report; <code>%p</code> is expanded to the name

  802. of the program, <code>%t</code> is expanded to a timestamp, <code>%%</code> is expanded

  803. to a plain <code>%</code>

  804. </p></dd>

  805. <dt><span><samp>level</samp></span></dt>

  806. <dd><p>set the log verbosity level using a numerical value (see <code>-loglevel</code>).

  807. </p></dd>

  808. </dl>

  809. 

  810. <p>For example, to output a report to a file named <samp>ffreport.log</samp>

  811. using a log level of <code>32</code> (alias for log level <code>info</code>):

  812. </p>

  813. <div class="example">

  814. <pre class="example">FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output

  815. </pre></div>

  816. 

  817. <p>Errors in parsing the environment variable are not fatal, and will not

  818. appear in the report.

  819. </p>

  820. </dd>

  821. <dt><span><samp>-hide_banner</samp></span></dt>

  822. <dd><p>Suppress printing banner.

  823. </p>

  824. <p>All FFmpeg tools will normally show a copyright notice, build options

  825. and library versions. This option can be used to suppress printing

  826. this information.

  827. </p>

  828. </dd>

  829. <dt><span><samp>-cpuflags flags (<em>global</em>)</samp></span></dt>

  830. <dd><p>Allows setting and clearing cpu flags. This option is intended

  831. for testing. Do not use it unless you know what you&rsquo;re doing.

  832. </p><div class="example">

  833. <pre class="example">ffmpeg -cpuflags -sse+mmx ...

  834. ffmpeg -cpuflags mmx ...

  835. ffmpeg -cpuflags 0 ...

  836. </pre></div>

  837. <p>Possible flags for this option are:

  838. </p><dl compact="compact">

  839. <dt><span>&lsquo;<samp>x86</samp>&rsquo;</span></dt>

  840. <dd><dl compact="compact">

  841. <dt><span>&lsquo;<samp>mmx</samp>&rsquo;</span></dt>

  842. <dt><span>&lsquo;<samp>mmxext</samp>&rsquo;</span></dt>

  843. <dt><span>&lsquo;<samp>sse</samp>&rsquo;</span></dt>

  844. <dt><span>&lsquo;<samp>sse2</samp>&rsquo;</span></dt>

  845. <dt><span>&lsquo;<samp>sse2slow</samp>&rsquo;</span></dt>

  846. <dt><span>&lsquo;<samp>sse3</samp>&rsquo;</span></dt>

  847. <dt><span>&lsquo;<samp>sse3slow</samp>&rsquo;</span></dt>

  848. <dt><span>&lsquo;<samp>ssse3</samp>&rsquo;</span></dt>

  849. <dt><span>&lsquo;<samp>atom</samp>&rsquo;</span></dt>

  850. <dt><span>&lsquo;<samp>sse4.1</samp>&rsquo;</span></dt>

  851. <dt><span>&lsquo;<samp>sse4.2</samp>&rsquo;</span></dt>

  852. <dt><span>&lsquo;<samp>avx</samp>&rsquo;</span></dt>

  853. <dt><span>&lsquo;<samp>avx2</samp>&rsquo;</span></dt>

  854. <dt><span>&lsquo;<samp>xop</samp>&rsquo;</span></dt>

  855. <dt><span>&lsquo;<samp>fma3</samp>&rsquo;</span></dt>

  856. <dt><span>&lsquo;<samp>fma4</samp>&rsquo;</span></dt>

  857. <dt><span>&lsquo;<samp>3dnow</samp>&rsquo;</span></dt>

  858. <dt><span>&lsquo;<samp>3dnowext</samp>&rsquo;</span></dt>

  859. <dt><span>&lsquo;<samp>bmi1</samp>&rsquo;</span></dt>

  860. <dt><span>&lsquo;<samp>bmi2</samp>&rsquo;</span></dt>

  861. <dt><span>&lsquo;<samp>cmov</samp>&rsquo;</span></dt>

  862. </dl>

  863. </dd>

  864. <dt><span>&lsquo;<samp>ARM</samp>&rsquo;</span></dt>

  865. <dd><dl compact="compact">

  866. <dt><span>&lsquo;<samp>armv5te</samp>&rsquo;</span></dt>

  867. <dt><span>&lsquo;<samp>armv6</samp>&rsquo;</span></dt>

  868. <dt><span>&lsquo;<samp>armv6t2</samp>&rsquo;</span></dt>

  869. <dt><span>&lsquo;<samp>vfp</samp>&rsquo;</span></dt>

  870. <dt><span>&lsquo;<samp>vfpv3</samp>&rsquo;</span></dt>

  871. <dt><span>&lsquo;<samp>neon</samp>&rsquo;</span></dt>

  872. <dt><span>&lsquo;<samp>setend</samp>&rsquo;</span></dt>

  873. </dl>

  874. </dd>

  875. <dt><span>&lsquo;<samp>AArch64</samp>&rsquo;</span></dt>

  876. <dd><dl compact="compact">

  877. <dt><span>&lsquo;<samp>armv8</samp>&rsquo;</span></dt>

  878. <dt><span>&lsquo;<samp>vfp</samp>&rsquo;</span></dt>

  879. <dt><span>&lsquo;<samp>neon</samp>&rsquo;</span></dt>

  880. </dl>

  881. </dd>

  882. <dt><span>&lsquo;<samp>PowerPC</samp>&rsquo;</span></dt>

  883. <dd><dl compact="compact">

  884. <dt><span>&lsquo;<samp>altivec</samp>&rsquo;</span></dt>

  885. </dl>

  886. </dd>

  887. <dt><span>&lsquo;<samp>Specific Processors</samp>&rsquo;</span></dt>

  888. <dd><dl compact="compact">

  889. <dt><span>&lsquo;<samp>pentium2</samp>&rsquo;</span></dt>

  890. <dt><span>&lsquo;<samp>pentium3</samp>&rsquo;</span></dt>

  891. <dt><span>&lsquo;<samp>pentium4</samp>&rsquo;</span></dt>

  892. <dt><span>&lsquo;<samp>k6</samp>&rsquo;</span></dt>

  893. <dt><span>&lsquo;<samp>k62</samp>&rsquo;</span></dt>

  894. <dt><span>&lsquo;<samp>athlon</samp>&rsquo;</span></dt>

  895. <dt><span>&lsquo;<samp>athlonxp</samp>&rsquo;</span></dt>

  896. <dt><span>&lsquo;<samp>k8</samp>&rsquo;</span></dt>

  897. </dl>

  898. </dd>

  899. </dl>

  900. 

  901. </dd>

  902. <dt><span><samp>-cpucount <var>count</var> (<em>global</em>)</samp></span></dt>

  903. <dd><p>Override detection of CPU count. This option is intended

  904. for testing. Do not use it unless you know what you&rsquo;re doing.

  905. </p><div class="example">

  906. <pre class="example">ffmpeg -cpucount 2

  907. </pre></div>

  908. 

  909. </dd>

  910. <dt><span><samp>-max_alloc <var>bytes</var></samp></span></dt>

  911. <dd><p>Set the maximum size limit for allocating a block on the heap by ffmpeg&rsquo;s

  912. family of malloc functions. Exercise <strong>extreme caution</strong> when using

  913. this option. Don&rsquo;t use if you do not understand the full consequence of doing so.

  914. Default is INT_MAX.

  915. </p></dd>

  916. </dl>

  917. 

  918. <a name="AVOptions"></a>

  919. <h3 class="section">5.3 AVOptions<span class="pull-right"><a class="anchor hidden-xs" href="#AVOptions" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-AVOptions" aria-hidden="true">TOC</a></span></h3>

  920. 

  921. <p>These options are provided directly by the libavformat, libavdevice and

  922. libavcodec libraries. To see the list of available AVOptions, use the

  923. <samp>-help</samp> option. They are separated into two categories:

  924. </p><dl compact="compact">

  925. <dt><span><samp>generic</samp></span></dt>

  926. <dd><p>These options can be set for any container, codec or device. Generic options

  927. are listed under AVFormatContext options for containers/devices and under

  928. AVCodecContext options for codecs.

  929. </p></dd>

  930. <dt><span><samp>private</samp></span></dt>

  931. <dd><p>These options are specific to the given container, device or codec. Private

  932. options are listed under their corresponding containers/devices/codecs.

  933. </p></dd>

  934. </dl>

  935. 

  936. <p>For example to write an ID3v2.3 header instead of a default ID3v2.4 to

  937. an MP3 file, use the <samp>id3v2_version</samp> private option of the MP3

  938. muxer:

  939. </p><div class="example">

  940. <pre class="example">ffmpeg -i input.flac -id3v2_version 3 out.mp3

  941. </pre></div>

  942. 

  943. <p>All codec AVOptions are per-stream, and thus a stream specifier

  944. should be attached to them:

  945. </p><div class="example">

  946. <pre class="example">ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4

  947. </pre></div>

  948. 

  949. <p>In the above example, a multichannel audio stream is mapped twice for output.

  950. The first instance is encoded with codec ac3 and bitrate 640k.

  951. The second instance is downmixed to 2 channels and encoded with codec aac. A bitrate of 128k is specified for it using

  952. absolute index of the output stream.

  953. </p>

  954. <p>Note: the <samp>-nooption</samp> syntax cannot be used for boolean

  955. AVOptions, use <samp>-option 0</samp>/<samp>-option 1</samp>.

  956. </p>

  957. <p>Note: the old undocumented way of specifying per-stream AVOptions by

  958. prepending v/a/s to the options name is now obsolete and will be

  959. removed soon.

  960. </p>

  961. <a name="Main-options"></a>

  962. <h3 class="section">5.4 Main options<span class="pull-right"><a class="anchor hidden-xs" href="#Main-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Main-options" aria-hidden="true">TOC</a></span></h3>

  963. 

  964. <dl compact="compact">

  965. <dt><span><samp>-f <var>fmt</var> (<em>input/output</em>)</samp></span></dt>

  966. <dd><p>Force input or output file format. The format is normally auto detected for input

  967. files and guessed from the file extension for output files, so this option is not

  968. needed in most cases.

  969. </p>

  970. </dd>

  971. <dt><span><samp>-i <var>url</var> (<em>input</em>)</samp></span></dt>

  972. <dd><p>input file url

  973. </p>

  974. </dd>

  975. <dt><span><samp>-y (<em>global</em>)</samp></span></dt>

  976. <dd><p>Overwrite output files without asking.

  977. </p>

  978. </dd>

  979. <dt><span><samp>-n (<em>global</em>)</samp></span></dt>

  980. <dd><p>Do not overwrite output files, and exit immediately if a specified

  981. output file already exists.

  982. </p>

  983. </dd>

  984. <dt><span><samp>-stream_loop <var>number</var> (<em>input</em>)</samp></span></dt>

  985. <dd><p>Set number of times input stream shall be looped. Loop 0 means no loop,

  986. loop -1 means infinite loop.

  987. </p>

  988. </dd>

  989. <dt><span><samp>-recast_media (<em>global</em>)</samp></span></dt>

  990. <dd><p>Allow forcing a decoder of a different media type than the one

  991. detected or designated by the demuxer. Useful for decoding media

  992. data muxed as data streams.

  993. </p>

  994. </dd>

  995. <dt><span><samp>-c[:<var>stream_specifier</var>] <var>codec</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  996. <dt><span><samp>-codec[:<var>stream_specifier</var>] <var>codec</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  997. <dd><p>Select an encoder (when used before an output file) or a decoder (when used

  998. before an input file) for one or more streams. <var>codec</var> is the name of a

  999. decoder/encoder or a special value <code>copy</code> (output only) to indicate that

  1000. the stream is not to be re-encoded.

  1001. </p>

  1002. <p>For example

  1003. </p><div class="example">

  1004. <pre class="example">ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT

  1005. </pre></div>

  1006. <p>encodes all video streams with libx264 and copies all audio streams.

  1007. </p>

  1008. <p>For each stream, the last matching <code>c</code> option is applied, so

  1009. </p><div class="example">

  1010. <pre class="example">ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT

  1011. </pre></div>

  1012. <p>will copy all the streams except the second video, which will be encoded with

  1013. libx264, and the 138th audio, which will be encoded with libvorbis.

  1014. </p>

  1015. </dd>

  1016. <dt><span><samp>-t <var>duration</var> (<em>input/output</em>)</samp></span></dt>

  1017. <dd><p>When used as an input option (before <code>-i</code>), limit the <var>duration</var> of

  1018. data read from the input file.

  1019. </p>

  1020. <p>When used as an output option (before an output url), stop writing the

  1021. output after its duration reaches <var>duration</var>.

  1022. </p>

  1023. <p><var>duration</var> must be a time duration specification,

  1024. see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>.

  1025. </p>

  1026. <p>-to and -t are mutually exclusive and -t has priority.

  1027. </p>

  1028. </dd>

  1029. <dt><span><samp>-to <var>position</var> (<em>input/output</em>)</samp></span></dt>

  1030. <dd><p>Stop writing the output or reading the input at <var>position</var>.

  1031. <var>position</var> must be a time duration specification,

  1032. see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>.

  1033. </p>

  1034. <p>-to and -t are mutually exclusive and -t has priority.

  1035. </p>

  1036. </dd>

  1037. <dt><span><samp>-fs <var>limit_size</var> (<em>output</em>)</samp></span></dt>

  1038. <dd><p>Set the file size limit, expressed in bytes. No further chunk of bytes is written

  1039. after the limit is exceeded. The size of the output file is slightly more than the

  1040. requested file size.

  1041. </p>

  1042. </dd>

  1043. <dt><span><samp>-ss <var>position</var> (<em>input/output</em>)</samp></span></dt>

  1044. <dd><p>When used as an input option (before <code>-i</code>), seeks in this input file to

  1045. <var>position</var>. Note that in most formats it is not possible to seek exactly,

  1046. so <code>ffmpeg</code> will seek to the closest seek point before <var>position</var>.

  1047. When transcoding and <samp>-accurate_seek</samp> is enabled (the default), this

  1048. extra segment between the seek point and <var>position</var> will be decoded and

  1049. discarded. When doing stream copy or when <samp>-noaccurate_seek</samp> is used, it

  1050. will be preserved.

  1051. </p>

  1052. <p>When used as an output option (before an output url), decodes but discards

  1053. input until the timestamps reach <var>position</var>.

  1054. </p>

  1055. <p><var>position</var> must be a time duration specification,

  1056. see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>.

  1057. </p>

  1058. </dd>

  1059. <dt><span><samp>-sseof <var>position</var> (<em>input</em>)</samp></span></dt>

  1060. <dd>

  1061. <p>Like the <code>-ss</code> option but relative to the &quot;end of file&quot;. That is negative

  1062. values are earlier in the file, 0 is at EOF.

  1063. </p>

  1064. </dd>

  1065. <dt><span><samp>-isync <var>input_index</var> (<em>input</em>)</samp></span></dt>

  1066. <dd><p>Assign an input as a sync source.

  1067. </p>

  1068. <p>This will take the difference between the start times of the target and reference inputs and

  1069. offset the timestamps of the target file by that difference. The source timestamps of the two

  1070. inputs should derive from the same clock source for expected results. If <code>copyts</code> is set

  1071. then <code>start_at_zero</code> must also be set. If either of the inputs has no starting timestamp

  1072. then no sync adjustment is made.

  1073. </p>

  1074. <p>Acceptable values are those that refer to a valid ffmpeg input index. If the sync reference is

  1075. the target index itself or <var>-1</var>, then no adjustment is made to target timestamps. A sync

  1076. reference may not itself be synced to any other input.

  1077. </p>

  1078. <p>Default value is <var>-1</var>.

  1079. </p>

  1080. </dd>

  1081. <dt><span><samp>-itsoffset <var>offset</var> (<em>input</em>)</samp></span></dt>

  1082. <dd><p>Set the input time offset.

  1083. </p>

  1084. <p><var>offset</var> must be a time duration specification,

  1085. see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#time-duration-syntax">(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual</a>.

  1086. </p>

  1087. <p>The offset is added to the timestamps of the input files. Specifying

  1088. a positive offset means that the corresponding streams are delayed by

  1089. the time duration specified in <var>offset</var>.

  1090. </p>

  1091. </dd>

  1092. <dt><span><samp>-itsscale <var>scale</var> (<em>input,per-stream</em>)</samp></span></dt>

  1093. <dd><p>Rescale input timestamps. <var>scale</var> should be a floating point number.

  1094. </p>

  1095. </dd>

  1096. <dt><span><samp>-timestamp <var>date</var> (<em>output</em>)</samp></span></dt>

  1097. <dd><p>Set the recording timestamp in the container.

  1098. </p>

  1099. <p><var>date</var> must be a date specification,

  1100. see <a data-manual="ffmpeg-utils" href="ffmpeg-utils.html#date-syntax">(ffmpeg-utils)the Date section in the ffmpeg-utils(1) manual</a>.

  1101. </p>

  1102. </dd>

  1103. <dt><span><samp>-metadata[:metadata_specifier] <var>key</var>=<var>value</var> (<em>output,per-metadata</em>)</samp></span></dt>

  1104. <dd><p>Set a metadata key/value pair.

  1105. </p>

  1106. <p>An optional <var>metadata_specifier</var> may be given to set metadata

  1107. on streams, chapters or programs. See <code>-map_metadata</code>

  1108. documentation for details.

  1109. </p>

  1110. <p>This option overrides metadata set with <code>-map_metadata</code>. It is

  1111. also possible to delete metadata by using an empty value.

  1112. </p>

  1113. <p>For example, for setting the title in the output file:

  1114. </p><div class="example">

  1115. <pre class="example">ffmpeg -i in.avi -metadata title=&quot;my title&quot; out.flv

  1116. </pre></div>

  1117. 

  1118. <p>To set the language of the first audio stream:

  1119. </p><div class="example">

  1120. <pre class="example">ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT

  1121. </pre></div>

  1122. 

  1123. </dd>

  1124. <dt><span><samp>-disposition[:stream_specifier] <var>value</var> (<em>output,per-stream</em>)</samp></span></dt>

  1125. <dd><p>Sets the disposition for a stream.

  1126. </p>

  1127. <p>By default, the disposition is copied from the input stream, unless the output

  1128. stream this option applies to is fed by a complex filtergraph - in that case the

  1129. disposition is unset by default.

  1130. </p>

  1131. <p><var>value</var> is a sequence of items separated by &rsquo;+&rsquo; or &rsquo;-&rsquo;. The first item may

  1132. also be prefixed with &rsquo;+&rsquo; or &rsquo;-&rsquo;, in which case this option modifies the default

  1133. value. Otherwise (the first item is not prefixed) this options overrides the

  1134. default value. A &rsquo;+&rsquo; prefix adds the given disposition, &rsquo;-&rsquo; removes it. It is

  1135. also possible to clear the disposition by setting it to 0.

  1136. </p>

  1137. <p>If no <code>-disposition</code> options were specified for an output file, ffmpeg will

  1138. automatically set the &rsquo;default&rsquo; disposition on the first stream of each type,

  1139. when there are multiple streams of this type in the output file and no stream of

  1140. that type is already marked as default.

  1141. </p>

  1142. <p>The <code>-dispositions</code> option lists the known dispositions.

  1143. </p>

  1144. <p>For example, to make the second audio stream the default stream:

  1145. </p><div class="example">

  1146. <pre class="example">ffmpeg -i in.mkv -c copy -disposition:a:1 default out.mkv

  1147. </pre></div>

  1148. 

  1149. <p>To make the second subtitle stream the default stream and remove the default

  1150. disposition from the first subtitle stream:

  1151. </p><div class="example">

  1152. <pre class="example">ffmpeg -i in.mkv -c copy -disposition:s:0 0 -disposition:s:1 default out.mkv

  1153. </pre></div>

  1154. 

  1155. <p>To add an embedded cover/thumbnail:

  1156. </p><div class="example">

  1157. <pre class="example">ffmpeg -i in.mp4 -i IMAGE -map 0 -map 1 -c copy -c:v:1 png -disposition:v:1 attached_pic out.mp4

  1158. </pre></div>

  1159. 

  1160. <p>Not all muxers support embedded thumbnails, and those who do, only support a few formats, like JPEG or PNG.

  1161. </p>

  1162. </dd>

  1163. <dt><span><samp>-program [title=<var>title</var>:][program_num=<var>program_num</var>:]st=<var>stream</var>[:st=<var>stream</var>...] (<em>output</em>)</samp></span></dt>

  1164. <dd>

  1165. <p>Creates a program with the specified <var>title</var>, <var>program_num</var> and adds the specified

  1166. <var>stream</var>(s) to it.

  1167. </p>

  1168. </dd>

  1169. <dt><span><samp>-target <var>type</var> (<em>output</em>)</samp></span></dt>

  1170. <dd><p>Specify target file type (<code>vcd</code>, <code>svcd</code>, <code>dvd</code>, <code>dv</code>,

  1171. <code>dv50</code>). <var>type</var> may be prefixed with <code>pal-</code>, <code>ntsc-</code> or

  1172. <code>film-</code> to use the corresponding standard. All the format options

  1173. (bitrate, codecs, buffer sizes) are then set automatically. You can just type:

  1174. </p>

  1175. <div class="example">

  1176. <pre class="example">ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg

  1177. </pre></div>

  1178. 

  1179. <p>Nevertheless you can specify additional options as long as you know

  1180. they do not conflict with the standard, as in:

  1181. </p>

  1182. <div class="example">

  1183. <pre class="example">ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg

  1184. </pre></div>

  1185. 

  1186. <p>The parameters set for each target are as follows.

  1187. </p>

  1188. <p><strong>VCD</strong>

  1189. </p><div class="example">

  1190. <pre class="example"><var>pal</var>:

  1191. -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324

  1192. -s 352x288 -r 25

  1193. -codec:v mpeg1video -g 15 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680

  1194. -ar 44100 -ac 2

  1195. -codec:a mp2 -b:a 224k

  1196. 

  1197. <var>ntsc</var>:

  1198. -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324

  1199. -s 352x240 -r 30000/1001

  1200. -codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680

  1201. -ar 44100 -ac 2

  1202. -codec:a mp2 -b:a 224k

  1203. 

  1204. <var>film</var>:

  1205. -f vcd -muxrate 1411200 -muxpreload 0.44 -packetsize 2324

  1206. -s 352x240 -r 24000/1001

  1207. -codec:v mpeg1video -g 18 -b:v 1150k -maxrate:v 1150k -minrate:v 1150k -bufsize:v 327680

  1208. -ar 44100 -ac 2

  1209. -codec:a mp2 -b:a 224k

  1210. </pre></div>

  1211. 

  1212. <p><strong>SVCD</strong>

  1213. </p><div class="example">

  1214. <pre class="example"><var>pal</var>:

  1215. -f svcd -packetsize 2324

  1216. -s 480x576 -pix_fmt yuv420p -r 25

  1217. -codec:v mpeg2video -g 15 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1

  1218. -ar 44100

  1219. -codec:a mp2 -b:a 224k

  1220. 

  1221. <var>ntsc</var>:

  1222. -f svcd -packetsize 2324

  1223. -s 480x480 -pix_fmt yuv420p -r 30000/1001

  1224. -codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1

  1225. -ar 44100

  1226. -codec:a mp2 -b:a 224k

  1227. 

  1228. <var>film</var>:

  1229. -f svcd -packetsize 2324

  1230. -s 480x480 -pix_fmt yuv420p -r 24000/1001

  1231. -codec:v mpeg2video -g 18 -b:v 2040k -maxrate:v 2516k -minrate:v 0 -bufsize:v 1835008 -scan_offset 1

  1232. -ar 44100

  1233. -codec:a mp2 -b:a 224k

  1234. </pre></div>

  1235. 

  1236. <p><strong>DVD</strong>

  1237. </p><div class="example">

  1238. <pre class="example"><var>pal</var>:

  1239. -f dvd -muxrate 10080k -packetsize 2048

  1240. -s 720x576 -pix_fmt yuv420p -r 25

  1241. -codec:v mpeg2video -g 15 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008

  1242. -ar 48000

  1243. -codec:a ac3 -b:a 448k

  1244. 

  1245. <var>ntsc</var>:

  1246. -f dvd -muxrate 10080k -packetsize 2048

  1247. -s 720x480 -pix_fmt yuv420p -r 30000/1001

  1248. -codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008

  1249. -ar 48000

  1250. -codec:a ac3 -b:a 448k

  1251. 

  1252. <var>film</var>:

  1253. -f dvd -muxrate 10080k -packetsize 2048

  1254. -s 720x480 -pix_fmt yuv420p -r 24000/1001

  1255. -codec:v mpeg2video -g 18 -b:v 6000k -maxrate:v 9000k -minrate:v 0 -bufsize:v 1835008

  1256. -ar 48000

  1257. -codec:a ac3 -b:a 448k

  1258. </pre></div>

  1259. 

  1260. <p><strong>DV</strong>

  1261. </p><div class="example">

  1262. <pre class="example"><var>pal</var>:

  1263. -f dv

  1264. -s 720x576 -pix_fmt yuv420p -r 25

  1265. -ar 48000 -ac 2

  1266. 

  1267. <var>ntsc</var>:

  1268. -f dv

  1269. -s 720x480 -pix_fmt yuv411p -r 30000/1001

  1270. -ar 48000 -ac 2

  1271. 

  1272. <var>film</var>:

  1273. -f dv

  1274. -s 720x480 -pix_fmt yuv411p -r 24000/1001

  1275. -ar 48000 -ac 2

  1276. </pre></div>

  1277. <p>The <code>dv50</code> target is identical to the <code>dv</code> target except that the pixel format set is <code>yuv422p</code> for all three standards.

  1278. </p>

  1279. <p>Any user-set value for a parameter above will override the target preset value. In that case, the output may

  1280. not comply with the target standard.

  1281. </p>

  1282. </dd>

  1283. <dt><span><samp>-dn (<em>input/output</em>)</samp></span></dt>

  1284. <dd><p>As an input option, blocks all data streams of a file from being filtered or

  1285. being automatically selected or mapped for any output. See <code>-discard</code>

  1286. option to disable streams individually.

  1287. </p>

  1288. <p>As an output option, disables data recording i.e. automatic selection or

  1289. mapping of any data stream. For full manual control see the <code>-map</code>

  1290. option.

  1291. </p>

  1292. </dd>

  1293. <dt><span><samp>-dframes <var>number</var> (<em>output</em>)</samp></span></dt>

  1294. <dd><p>Set the number of data frames to output. This is an obsolete alias for

  1295. <code>-frames:d</code>, which you should use instead.

  1296. </p>

  1297. </dd>

  1298. <dt><span><samp>-frames[:<var>stream_specifier</var>] <var>framecount</var> (<em>output,per-stream</em>)</samp></span></dt>

  1299. <dd><p>Stop writing to the stream after <var>framecount</var> frames.

  1300. </p>

  1301. </dd>

  1302. <dt><span><samp>-q[:<var>stream_specifier</var>] <var>q</var> (<em>output,per-stream</em>)</samp></span></dt>

  1303. <dt><span><samp>-qscale[:<var>stream_specifier</var>] <var>q</var> (<em>output,per-stream</em>)</samp></span></dt>

  1304. <dd><p>Use fixed quality scale (VBR). The meaning of <var>q</var>/<var>qscale</var> is

  1305. codec-dependent.

  1306. If <var>qscale</var> is used without a <var>stream_specifier</var> then it applies only

  1307. to the video stream, this is to maintain compatibility with previous behavior

  1308. and as specifying the same codec specific value to 2 different codecs that is

  1309. audio and video generally is not what is intended when no stream_specifier is

  1310. used.

  1311. </p>

  1312. <span id="filter_005foption"></span></dd>

  1313. <dt><span><samp>-filter[:<var>stream_specifier</var>] <var>filtergraph</var> (<em>output,per-stream</em>)</samp></span></dt>

  1314. <dd><p>Create the filtergraph specified by <var>filtergraph</var> and use it to

  1315. filter the stream.

  1316. </p>

  1317. <p><var>filtergraph</var> is a description of the filtergraph to apply to

  1318. the stream, and must have a single input and a single output of the

  1319. same type of the stream. In the filtergraph, the input is associated

  1320. to the label <code>in</code>, and the output to the label <code>out</code>. See

  1321. the ffmpeg-filters manual for more information about the filtergraph

  1322. syntax.

  1323. </p>

  1324. <p>See the <a href="#filter_005fcomplex_005foption">-filter_complex option</a> if you

  1325. want to create filtergraphs with multiple inputs and/or outputs.

  1326. </p>

  1327. </dd>

  1328. <dt><span><samp>-filter_script[:<var>stream_specifier</var>] <var>filename</var> (<em>output,per-stream</em>)</samp></span></dt>

  1329. <dd><p>This option is similar to <samp>-filter</samp>, the only difference is that its

  1330. argument is the name of the file from which a filtergraph description is to be

  1331. read.

  1332. </p>

  1333. </dd>

  1334. <dt><span><samp>-reinit_filter[:<var>stream_specifier</var>] <var>integer</var> (<em>input,per-stream</em>)</samp></span></dt>

  1335. <dd><p>This boolean option determines if the filtergraph(s) to which this stream is fed gets

  1336. reinitialized when input frame parameters change mid-stream. This option is enabled by

  1337. default as most video and all audio filters cannot handle deviation in input frame properties.

  1338. Upon reinitialization, existing filter state is lost, like e.g. the frame count <code>n</code>

  1339. reference available in some filters. Any frames buffered at time of reinitialization are lost.

  1340. The properties where a change triggers reinitialization are,

  1341. for video, frame resolution or pixel format;

  1342. for audio, sample format, sample rate, channel count or channel layout.

  1343. </p>

  1344. </dd>

  1345. <dt><span><samp>-filter_threads <var>nb_threads</var> (<em>global</em>)</samp></span></dt>

  1346. <dd><p>Defines how many threads are used to process a filter pipeline. Each pipeline

  1347. will produce a thread pool with this many threads available for parallel processing.

  1348. The default is the number of available CPUs.

  1349. </p>

  1350. </dd>

  1351. <dt><span><samp>-pre[:<var>stream_specifier</var>] <var>preset_name</var> (<em>output,per-stream</em>)</samp></span></dt>

  1352. <dd><p>Specify the preset for matching stream(s).

  1353. </p>

  1354. </dd>

  1355. <dt><span><samp>-stats (<em>global</em>)</samp></span></dt>

  1356. <dd><p>Print encoding progress/statistics. It is on by default, to explicitly

  1357. disable it you need to specify <code>-nostats</code>.

  1358. </p>

  1359. </dd>

  1360. <dt><span><samp>-stats_period <var>time</var> (<em>global</em>)</samp></span></dt>

  1361. <dd><p>Set period at which encoding progress/statistics are updated. Default is 0.5 seconds.

  1362. </p>

  1363. </dd>

  1364. <dt><span><samp>-progress <var>url</var> (<em>global</em>)</samp></span></dt>

  1365. <dd><p>Send program-friendly progress information to <var>url</var>.

  1366. </p>

  1367. <p>Progress information is written periodically and at the end of

  1368. the encoding process. It is made of &quot;<var>key</var>=<var>value</var>&quot; lines. <var>key</var>

  1369. consists of only alphanumeric characters. The last key of a sequence of

  1370. progress information is always &quot;progress&quot;.

  1371. </p>

  1372. <p>The update period is set using <code>-stats_period</code>.

  1373. </p>

  1374. <span id="stdin-option"></span></dd>

  1375. <dt><span><samp>-stdin</samp></span></dt>

  1376. <dd><p>Enable interaction on standard input. On by default unless standard input is

  1377. used as an input. To explicitly disable interaction you need to specify

  1378. <code>-nostdin</code>.

  1379. </p>

  1380. <p>Disabling interaction on standard input is useful, for example, if

  1381. ffmpeg is in the background process group. Roughly the same result can

  1382. be achieved with <code>ffmpeg ... &lt; /dev/null</code> but it requires a

  1383. shell.

  1384. </p>

  1385. </dd>

  1386. <dt><span><samp>-debug_ts (<em>global</em>)</samp></span></dt>

  1387. <dd><p>Print timestamp information. It is off by default. This option is

  1388. mostly useful for testing and debugging purposes, and the output

  1389. format may change from one version to another, so it should not be

  1390. employed by portable scripts.

  1391. </p>

  1392. <p>See also the option <code>-fdebug ts</code>.

  1393. </p>

  1394. </dd>

  1395. <dt><span><samp>-attach <var>filename</var> (<em>output</em>)</samp></span></dt>

  1396. <dd><p>Add an attachment to the output file. This is supported by a few formats

  1397. like Matroska for e.g. fonts used in rendering subtitles. Attachments

  1398. are implemented as a specific type of stream, so this option will add

  1399. a new stream to the file. It is then possible to use per-stream options

  1400. on this stream in the usual way. Attachment streams created with this

  1401. option will be created after all the other streams (i.e. those created

  1402. with <code>-map</code> or automatic mappings).

  1403. </p>

  1404. <p>Note that for Matroska you also have to set the mimetype metadata tag:

  1405. </p><div class="example">

  1406. <pre class="example">ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv

  1407. </pre></div>

  1408. <p>(assuming that the attachment stream will be third in the output file).

  1409. </p>

  1410. </dd>

  1411. <dt><span><samp>-dump_attachment[:<var>stream_specifier</var>] <var>filename</var> (<em>input,per-stream</em>)</samp></span></dt>

  1412. <dd><p>Extract the matching attachment stream into a file named <var>filename</var>. If

  1413. <var>filename</var> is empty, then the value of the <code>filename</code> metadata tag

  1414. will be used.

  1415. </p>

  1416. <p>E.g. to extract the first attachment to a file named &rsquo;out.ttf&rsquo;:

  1417. </p><div class="example">

  1418. <pre class="example">ffmpeg -dump_attachment:t:0 out.ttf -i INPUT

  1419. </pre></div>

  1420. <p>To extract all attachments to files determined by the <code>filename</code> tag:

  1421. </p><div class="example">

  1422. <pre class="example">ffmpeg -dump_attachment:t &quot;&quot; -i INPUT

  1423. </pre></div>

  1424. 

  1425. <p>Technical note &ndash; attachments are implemented as codec extradata, so this

  1426. option can actually be used to extract extradata from any stream, not just

  1427. attachments.

  1428. </p></dd>

  1429. </dl>

  1430. 

  1431. <a name="Video-Options"></a>

  1432. <h3 class="section">5.5 Video Options<span class="pull-right"><a class="anchor hidden-xs" href="#Video-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-Options" aria-hidden="true">TOC</a></span></h3>

  1433. 

  1434. <dl compact="compact">

  1435. <dt><span><samp>-vframes <var>number</var> (<em>output</em>)</samp></span></dt>

  1436. <dd><p>Set the number of video frames to output. This is an obsolete alias for

  1437. <code>-frames:v</code>, which you should use instead.

  1438. </p></dd>

  1439. <dt><span><samp>-r[:<var>stream_specifier</var>] <var>fps</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  1440. <dd><p>Set frame rate (Hz value, fraction or abbreviation).

  1441. </p>

  1442. <p>As an input option, ignore any timestamps stored in the file and instead

  1443. generate timestamps assuming constant frame rate <var>fps</var>.

  1444. This is not the same as the <samp>-framerate</samp> option used for some input formats

  1445. like image2 or v4l2 (it used to be the same in older versions of FFmpeg).

  1446. If in doubt use <samp>-framerate</samp> instead of the input option <samp>-r</samp>.

  1447. </p>

  1448. <p>As an output option:

  1449. </p><dl compact="compact">

  1450. <dt><span><samp>video encoding</samp></span></dt>

  1451. <dd><p>Duplicate or drop frames right before encoding them to achieve constant output

  1452. frame rate <var>fps</var>.

  1453. </p>

  1454. </dd>

  1455. <dt><span><samp>video streamcopy</samp></span></dt>

  1456. <dd><p>Indicate to the muxer that <var>fps</var> is the stream frame rate. No data is

  1457. dropped or duplicated in this case. This may produce invalid files if <var>fps</var>

  1458. does not match the actual stream frame rate as determined by packet timestamps.

  1459. See also the <code>setts</code> bitstream filter.

  1460. </p>

  1461. </dd>

  1462. </dl>

  1463. 

  1464. </dd>

  1465. <dt><span><samp>-fpsmax[:<var>stream_specifier</var>] <var>fps</var> (<em>output,per-stream</em>)</samp></span></dt>

  1466. <dd><p>Set maximum frame rate (Hz value, fraction or abbreviation).

  1467. </p>

  1468. <p>Clamps output frame rate when output framerate is auto-set and is higher than this value.

  1469. Useful in batch processing or when input framerate is wrongly detected as very high.

  1470. It cannot be set together with <code>-r</code>. It is ignored during streamcopy.

  1471. </p>

  1472. </dd>

  1473. <dt><span><samp>-s[:<var>stream_specifier</var>] <var>size</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  1474. <dd><p>Set frame size.

  1475. </p>

  1476. <p>As an input option, this is a shortcut for the <samp>video_size</samp> private

  1477. option, recognized by some demuxers for which the frame size is either not

  1478. stored in the file or is configurable &ndash; e.g. raw video or video grabbers.

  1479. </p>

  1480. <p>As an output option, this inserts the <code>scale</code> video filter to the

  1481. <em>end</em> of the corresponding filtergraph. Please use the <code>scale</code> filter

  1482. directly to insert it at the beginning or some other place.

  1483. </p>

  1484. <p>The format is &lsquo;<samp>wxh</samp>&rsquo; (default - same as source).

  1485. </p>

  1486. </dd>

  1487. <dt><span><samp>-aspect[:<var>stream_specifier</var>] <var>aspect</var> (<em>output,per-stream</em>)</samp></span></dt>

  1488. <dd><p>Set the video display aspect ratio specified by <var>aspect</var>.

  1489. </p>

  1490. <p><var>aspect</var> can be a floating point number string, or a string of the

  1491. form <var>num</var>:<var>den</var>, where <var>num</var> and <var>den</var> are the

  1492. numerator and denominator of the aspect ratio. For example &quot;4:3&quot;,

  1493. &quot;16:9&quot;, &quot;1.3333&quot;, and &quot;1.7777&quot; are valid argument values.

  1494. </p>

  1495. <p>If used together with <samp>-vcodec copy</samp>, it will affect the aspect ratio

  1496. stored at container level, but not the aspect ratio stored in encoded

  1497. frames, if it exists.

  1498. </p>

  1499. </dd>

  1500. <dt><span><samp>-display_rotation[:<var>stream_specifier</var>] <var>rotation</var> (<em>input,per-stream</em>)</samp></span></dt>

  1501. <dd><p>Set video rotation metadata.

  1502. </p>

  1503. <p><var>rotation</var> is a decimal number specifying the amount in degree by

  1504. which the video should be rotated counter-clockwise before being

  1505. displayed.

  1506. </p>

  1507. <p>This option overrides the rotation/display transform metadata stored in

  1508. the file, if any. When the video is being transcoded (rather than

  1509. copied) and <code>-autorotate</code> is enabled, the video will be rotated at

  1510. the filtering stage. Otherwise, the metadata will be written into the

  1511. output file if the muxer supports it.

  1512. </p>

  1513. <p>If the <code>-display_hflip</code> and/or <code>-display_vflip</code> options are

  1514. given, they are applied after the rotation specified by this option.

  1515. </p>

  1516. </dd>

  1517. <dt><span><samp>-display_hflip[:<var>stream_specifier</var>] (<em>input,per-stream</em>)</samp></span></dt>

  1518. <dd><p>Set whether on display the image should be horizontally flipped.

  1519. </p>

  1520. <p>See the <code>-display_rotation</code> option for more details.

  1521. </p>

  1522. </dd>

  1523. <dt><span><samp>-display_vflip[:<var>stream_specifier</var>] (<em>input,per-stream</em>)</samp></span></dt>

  1524. <dd><p>Set whether on display the image should be vertically flipped.

  1525. </p>

  1526. <p>See the <code>-display_rotation</code> option for more details.

  1527. </p>

  1528. </dd>

  1529. <dt><span><samp>-vn (<em>input/output</em>)</samp></span></dt>

  1530. <dd><p>As an input option, blocks all video streams of a file from being filtered or

  1531. being automatically selected or mapped for any output. See <code>-discard</code>

  1532. option to disable streams individually.

  1533. </p>

  1534. <p>As an output option, disables video recording i.e. automatic selection or

  1535. mapping of any video stream. For full manual control see the <code>-map</code>

  1536. option.

  1537. </p>

  1538. </dd>

  1539. <dt><span><samp>-vcodec <var>codec</var> (<em>output</em>)</samp></span></dt>

  1540. <dd><p>Set the video codec. This is an alias for <code>-codec:v</code>.

  1541. </p>

  1542. </dd>

  1543. <dt><span><samp>-pass[:<var>stream_specifier</var>] <var>n</var> (<em>output,per-stream</em>)</samp></span></dt>

  1544. <dd><p>Select the pass number (1 or 2). It is used to do two-pass

  1545. video encoding. The statistics of the video are recorded in the first

  1546. pass into a log file (see also the option -passlogfile),

  1547. and in the second pass that log file is used to generate the video

  1548. at the exact requested bitrate.

  1549. On pass 1, you may just deactivate audio and set output to null,

  1550. examples for Windows and Unix:

  1551. </p><div class="example">

  1552. <pre class="example">ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL

  1553. ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null

  1554. </pre></div>

  1555. 

  1556. </dd>

  1557. <dt><span><samp>-passlogfile[:<var>stream_specifier</var>] <var>prefix</var> (<em>output,per-stream</em>)</samp></span></dt>

  1558. <dd><p>Set two-pass log file name prefix to <var>prefix</var>, the default file name

  1559. prefix is &ldquo;ffmpeg2pass&rdquo;. The complete file name will be

  1560. <samp>PREFIX-N.log</samp>, where N is a number specific to the output

  1561. stream

  1562. </p>

  1563. </dd>

  1564. <dt><span><samp>-vf <var>filtergraph</var> (<em>output</em>)</samp></span></dt>

  1565. <dd><p>Create the filtergraph specified by <var>filtergraph</var> and use it to

  1566. filter the stream.

  1567. </p>

  1568. <p>This is an alias for <code>-filter:v</code>, see the <a href="#filter_005foption">-filter option</a>.

  1569. </p>

  1570. </dd>

  1571. <dt><span><samp>-autorotate</samp></span></dt>

  1572. <dd><p>Automatically rotate the video according to file metadata. Enabled by

  1573. default, use <samp>-noautorotate</samp> to disable it.

  1574. </p>

  1575. </dd>

  1576. <dt><span><samp>-autoscale</samp></span></dt>

  1577. <dd><p>Automatically scale the video according to the resolution of first frame.

  1578. Enabled by default, use <samp>-noautoscale</samp> to disable it. When autoscale is

  1579. disabled, all output frames of filter graph might not be in the same resolution

  1580. and may be inadequate for some encoder/muxer. Therefore, it is not recommended

  1581. to disable it unless you really know what you are doing.

  1582. Disable autoscale at your own risk.

  1583. </p></dd>

  1584. </dl>

  1585. 

  1586. <a name="Advanced-Video-options"></a>

  1587. <h3 class="section">5.6 Advanced Video options<span class="pull-right"><a class="anchor hidden-xs" href="#Advanced-Video-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Advanced-Video-options" aria-hidden="true">TOC</a></span></h3>

  1588. 

  1589. <dl compact="compact">

  1590. <dt><span><samp>-pix_fmt[:<var>stream_specifier</var>] <var>format</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  1591. <dd><p>Set pixel format. Use <code>-pix_fmts</code> to show all the supported

  1592. pixel formats.

  1593. If the selected pixel format can not be selected, ffmpeg will print a

  1594. warning and select the best pixel format supported by the encoder.

  1595. If <var>pix_fmt</var> is prefixed by a <code>+</code>, ffmpeg will exit with an error

  1596. if the requested pixel format can not be selected, and automatic conversions

  1597. inside filtergraphs are disabled.

  1598. If <var>pix_fmt</var> is a single <code>+</code>, ffmpeg selects the same pixel format

  1599. as the input (or graph output) and automatic conversions are disabled.

  1600. </p>

  1601. </dd>

  1602. <dt><span><samp>-sws_flags <var>flags</var> (<em>input/output</em>)</samp></span></dt>

  1603. <dd><p>Set SwScaler flags.

  1604. </p>

  1605. </dd>

  1606. <dt><span><samp>-rc_override[:<var>stream_specifier</var>] <var>override</var> (<em>output,per-stream</em>)</samp></span></dt>

  1607. <dd><p>Rate control override for specific intervals, formatted as &quot;int,int,int&quot;

  1608. list separated with slashes. Two first values are the beginning and

  1609. end frame numbers, last one is quantizer to use if positive, or quality

  1610. factor if negative.

  1611. </p>

  1612. </dd>

  1613. <dt><span><samp>-psnr</samp></span></dt>

  1614. <dd><p>Calculate PSNR of compressed frames. This option is deprecated, pass the

  1615. PSNR flag to the encoder instead, using <code>-flags +psnr</code>.

  1616. </p></dd>

  1617. <dt><span><samp>-vstats</samp></span></dt>

  1618. <dd><p>Dump video coding statistics to <samp>vstats_HHMMSS.log</samp>.

  1619. </p></dd>

  1620. <dt><span><samp>-vstats_file <var>file</var></samp></span></dt>

  1621. <dd><p>Dump video coding statistics to <var>file</var>.

  1622. </p></dd>

  1623. <dt><span><samp>-vstats_version <var>file</var></samp></span></dt>

  1624. <dd><p>Specifies which version of the vstats format to use. Default is 2.

  1625. </p>

  1626. <p>version = 1 :

  1627. </p>

  1628. <p><code>frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s</code>

  1629. </p>

  1630. <p>version &gt; 1:

  1631. </p>

  1632. <p><code>out= %2d st= %2d frame= %5d q= %2.1f PSNR= %6.2f f_size= %6d s_size= %8.0fkB time= %0.3f br= %7.1fkbits/s avg_br= %7.1fkbits/s</code>

  1633. </p></dd>

  1634. <dt><span><samp>-top[:<var>stream_specifier</var>] <var>n</var> (<em>output,per-stream</em>)</samp></span></dt>

  1635. <dd><p>top=1/bottom=0/auto=-1 field first

  1636. </p></dd>

  1637. <dt><span><samp>-vtag <var>fourcc/tag</var> (<em>output</em>)</samp></span></dt>

  1638. <dd><p>Force video tag/fourcc. This is an alias for <code>-tag:v</code>.

  1639. </p></dd>

  1640. <dt><span><samp>-qphist (<em>global</em>)</samp></span></dt>

  1641. <dd><p>Show QP histogram

  1642. </p></dd>

  1643. <dt><span><samp>-vbsf <var>bitstream_filter</var></samp></span></dt>

  1644. <dd><p>Deprecated see -bsf

  1645. </p>

  1646. </dd>

  1647. <dt><span><samp>-force_key_frames[:<var>stream_specifier</var>] <var>time</var>[,<var>time</var>...] (<em>output,per-stream</em>)</samp></span></dt>

  1648. <dt><span><samp>-force_key_frames[:<var>stream_specifier</var>] expr:<var>expr</var> (<em>output,per-stream</em>)</samp></span></dt>

  1649. <dt><span><samp>-force_key_frames[:<var>stream_specifier</var>] source (<em>output,per-stream</em>)</samp></span></dt>

  1650. <dt><span><samp>-force_key_frames[:<var>stream_specifier</var>] source_no_drop (<em>output,per-stream</em>)</samp></span></dt>

  1651. <dd>

  1652. <p><var>force_key_frames</var> can take arguments of the following form:

  1653. </p>

  1654. <dl compact="compact">

  1655. <dt><span><samp><var>time</var>[,<var>time</var>...]</samp></span></dt>

  1656. <dd><p>If the argument consists of timestamps, ffmpeg will round the specified times to the nearest

  1657. output timestamp as per the encoder time base and force a keyframe at the first frame having

  1658. timestamp equal or greater than the computed timestamp. Note that if the encoder time base is too

  1659. coarse, then the keyframes may be forced on frames with timestamps lower than the specified time.

  1660. The default encoder time base is the inverse of the output framerate but may be set otherwise

  1661. via <code>-enc_time_base</code>.

  1662. </p>

  1663. <p>If one of the times is &quot;<code>chapters</code>[<var>delta</var>]&quot;, it is expanded into

  1664. the time of the beginning of all chapters in the file, shifted by

  1665. <var>delta</var>, expressed as a time in seconds.

  1666. This option can be useful to ensure that a seek point is present at a

  1667. chapter mark or any other designated place in the output file.

  1668. </p>

  1669. <p>For example, to insert a key frame at 5 minutes, plus key frames 0.1 second

  1670. before the beginning of every chapter:

  1671. </p><div class="example">

  1672. <pre class="example">-force_key_frames 0:05:00,chapters-0.1

  1673. </pre></div>

  1674. 

  1675. </dd>

  1676. <dt><span><samp>expr:<var>expr</var></samp></span></dt>

  1677. <dd><p>If the argument is prefixed with <code>expr:</code>, the string <var>expr</var>

  1678. is interpreted like an expression and is evaluated for each frame. A

  1679. key frame is forced in case the evaluation is non-zero.

  1680. </p>

  1681. <p>The expression in <var>expr</var> can contain the following constants:

  1682. </p><dl compact="compact">

  1683. <dt><span><samp>n</samp></span></dt>

  1684. <dd><p>the number of current processed frame, starting from 0

  1685. </p></dd>

  1686. <dt><span><samp>n_forced</samp></span></dt>

  1687. <dd><p>the number of forced frames

  1688. </p></dd>

  1689. <dt><span><samp>prev_forced_n</samp></span></dt>

  1690. <dd><p>the number of the previous forced frame, it is <code>NAN</code> when no

  1691. keyframe was forced yet

  1692. </p></dd>

  1693. <dt><span><samp>prev_forced_t</samp></span></dt>

  1694. <dd><p>the time of the previous forced frame, it is <code>NAN</code> when no

  1695. keyframe was forced yet

  1696. </p></dd>

  1697. <dt><span><samp>t</samp></span></dt>

  1698. <dd><p>the time of the current processed frame

  1699. </p></dd>

  1700. </dl>

  1701. 

  1702. <p>For example to force a key frame every 5 seconds, you can specify:

  1703. </p><div class="example">

  1704. <pre class="example">-force_key_frames expr:gte(t,n_forced*5)

  1705. </pre></div>

  1706. 

  1707. <p>To force a key frame 5 seconds after the time of the last forced one,

  1708. starting from second 13:

  1709. </p><div class="example">

  1710. <pre class="example">-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))

  1711. </pre></div>

  1712. 

  1713. </dd>

  1714. <dt><span><samp>source</samp></span></dt>

  1715. <dd><p>If the argument is <code>source</code>, ffmpeg will force a key frame if

  1716. the current frame being encoded is marked as a key frame in its source.

  1717. </p>

  1718. </dd>

  1719. <dt><span><samp>source_no_drop</samp></span></dt>

  1720. <dd><p>If the argument is <code>source_no_drop</code>, ffmpeg will force a key frame if

  1721. the current frame being encoded is marked as a key frame in its source.

  1722. In cases where this particular source frame has to be dropped,

  1723. enforce the next available frame to become a key frame instead.

  1724. </p>

  1725. </dd>

  1726. </dl>

  1727. 

  1728. <p>Note that forcing too many keyframes is very harmful for the lookahead

  1729. algorithms of certain encoders: using fixed-GOP options or similar

  1730. would be more efficient.

  1731. </p>

  1732. </dd>

  1733. <dt><span><samp>-copyinkf[:<var>stream_specifier</var>] (<em>output,per-stream</em>)</samp></span></dt>

  1734. <dd><p>When doing stream copy, copy also non-key frames found at the

  1735. beginning.

  1736. </p>

  1737. </dd>

  1738. <dt><span><samp>-init_hw_device <var>type</var>[=<var>name</var>][:<var>device</var>[,<var>key=value</var>...]]</samp></span></dt>

  1739. <dd><p>Initialise a new hardware device of type <var>type</var> called <var>name</var>, using the

  1740. given device parameters.

  1741. If no name is specified it will receive a default name of the form &quot;<var>type</var>%d&quot;.

  1742. </p>

  1743. <p>The meaning of <var>device</var> and the following arguments depends on the

  1744. device type:

  1745. </p><dl compact="compact">

  1746. <dt><span><samp>cuda</samp></span></dt>

  1747. <dd><p><var>device</var> is the number of the CUDA device.

  1748. </p>

  1749. <p>The following options are recognized:

  1750. </p><dl compact="compact">

  1751. <dt><span><samp>primary_ctx</samp></span></dt>

  1752. <dd><p>If set to 1, uses the primary device context instead of creating a new one.

  1753. </p></dd>

  1754. </dl>

  1755. 

  1756. <p>Examples:

  1757. </p><dl compact="compact">

  1758. <dt><span><em>-init_hw_device cuda:1</em></span></dt>

  1759. <dd><p>Choose the second device on the system.

  1760. </p>

  1761. </dd>

  1762. <dt><span><em>-init_hw_device cuda:0,primary_ctx=1</em></span></dt>

  1763. <dd><p>Choose the first device and use the primary device context.

  1764. </p></dd>

  1765. </dl>

  1766. 

  1767. </dd>

  1768. <dt><span><samp>dxva2</samp></span></dt>

  1769. <dd><p><var>device</var> is the number of the Direct3D 9 display adapter.

  1770. </p>

  1771. </dd>

  1772. <dt><span><samp>d3d11va</samp></span></dt>

  1773. <dd><p><var>device</var> is the number of the Direct3D 11 display adapter.

  1774. </p>

  1775. </dd>

  1776. <dt><span><samp>vaapi</samp></span></dt>

  1777. <dd><p><var>device</var> is either an X11 display name or a DRM render node.

  1778. If not specified, it will attempt to open the default X11 display (<em>$DISPLAY</em>)

  1779. and then the first DRM render node (<em>/dev/dri/renderD128</em>).

  1780. </p>

  1781. </dd>

  1782. <dt><span><samp>vdpau</samp></span></dt>

  1783. <dd><p><var>device</var> is an X11 display name.

  1784. If not specified, it will attempt to open the default X11 display (<em>$DISPLAY</em>).

  1785. </p>

  1786. </dd>

  1787. <dt><span><samp>qsv</samp></span></dt>

  1788. <dd><p><var>device</var> selects a value in &lsquo;<samp>MFX_IMPL_*</samp>&rsquo;. Allowed values are:

  1789. </p><dl compact="compact">

  1790. <dt><span><samp>auto</samp></span></dt>

  1791. <dt><span><samp>sw</samp></span></dt>

  1792. <dt><span><samp>hw</samp></span></dt>

  1793. <dt><span><samp>auto_any</samp></span></dt>

  1794. <dt><span><samp>hw_any</samp></span></dt>

  1795. <dt><span><samp>hw2</samp></span></dt>

  1796. <dt><span><samp>hw3</samp></span></dt>

  1797. <dt><span><samp>hw4</samp></span></dt>

  1798. </dl>

  1799. <p>If not specified, &lsquo;<samp>auto_any</samp>&rsquo; is used.

  1800. (Note that it may be easier to achieve the desired result for QSV by creating the

  1801. platform-appropriate subdevice (&lsquo;<samp>dxva2</samp>&rsquo; or &lsquo;<samp>d3d11va</samp>&rsquo; or &lsquo;<samp>vaapi</samp>&rsquo;) and then deriving a

  1802. QSV device from that.)

  1803. </p>

  1804. <p>Alternatively, &lsquo;<samp>child_device_type</samp>&rsquo; helps to choose platform-appropriate subdevice type.

  1805. On Windows &lsquo;<samp>d3d11va</samp>&rsquo; is used as default subdevice type.

  1806. </p>

  1807. <p>Examples:

  1808. </p><dl compact="compact">

  1809. <dt><span><em>-init_hw_device qsv:hw,child_device_type=d3d11va</em></span></dt>

  1810. <dd><p>Choose the GPU subdevice with type &lsquo;<samp>d3d11va</samp>&rsquo; and create QSV device with &lsquo;<samp>MFX_IMPL_HARDWARE</samp>&rsquo;.

  1811. </p>

  1812. </dd>

  1813. <dt><span><em>-init_hw_device qsv:hw,child_device_type=dxva2</em></span></dt>

  1814. <dd><p>Choose the GPU subdevice with type &lsquo;<samp>dxva2</samp>&rsquo; and create QSV device with &lsquo;<samp>MFX_IMPL_HARDWARE</samp>&rsquo;.

  1815. </p></dd>

  1816. </dl>

  1817. 

  1818. </dd>

  1819. <dt><span><samp>opencl</samp></span></dt>

  1820. <dd><p><var>device</var> selects the platform and device as <em>platform_index.device_index</em>.

  1821. </p>

  1822. <p>The set of devices can also be filtered using the key-value pairs to find only

  1823. devices matching particular platform or device strings.

  1824. </p>

  1825. <p>The strings usable as filters are:

  1826. </p><dl compact="compact">

  1827. <dt><span><samp>platform_profile</samp></span></dt>

  1828. <dt><span><samp>platform_version</samp></span></dt>

  1829. <dt><span><samp>platform_name</samp></span></dt>

  1830. <dt><span><samp>platform_vendor</samp></span></dt>

  1831. <dt><span><samp>platform_extensions</samp></span></dt>

  1832. <dt><span><samp>device_name</samp></span></dt>

  1833. <dt><span><samp>device_vendor</samp></span></dt>

  1834. <dt><span><samp>driver_version</samp></span></dt>

  1835. <dt><span><samp>device_version</samp></span></dt>

  1836. <dt><span><samp>device_profile</samp></span></dt>

  1837. <dt><span><samp>device_extensions</samp></span></dt>

  1838. <dt><span><samp>device_type</samp></span></dt>

  1839. </dl>

  1840. 

  1841. <p>The indices and filters must together uniquely select a device.

  1842. </p>

  1843. <p>Examples:

  1844. </p><dl compact="compact">

  1845. <dt><span><em>-init_hw_device opencl:0.1</em></span></dt>

  1846. <dd><p>Choose the second device on the first platform.

  1847. </p>

  1848. </dd>

  1849. <dt><span><em>-init_hw_device opencl:,device_name=Foo9000</em></span></dt>

  1850. <dd><p>Choose the device with a name containing the string <em>Foo9000</em>.

  1851. </p>

  1852. </dd>

  1853. <dt><span><em>-init_hw_device opencl:1,device_type=gpu,device_extensions=cl_khr_fp16</em></span></dt>

  1854. <dd><p>Choose the GPU device on the second platform supporting the <em>cl_khr_fp16</em>

  1855. extension.

  1856. </p></dd>

  1857. </dl>

  1858. 

  1859. </dd>

  1860. <dt><span><samp>vulkan</samp></span></dt>

  1861. <dd><p>If <var>device</var> is an integer, it selects the device by its index in a

  1862. system-dependent list of devices.  If <var>device</var> is any other string, it

  1863. selects the first device with a name containing that string as a substring.

  1864. </p>

  1865. <p>The following options are recognized:

  1866. </p><dl compact="compact">

  1867. <dt><span><samp>debug</samp></span></dt>

  1868. <dd><p>If set to 1, enables the validation layer, if installed.

  1869. </p></dd>

  1870. <dt><span><samp>linear_images</samp></span></dt>

  1871. <dd><p>If set to 1, images allocated by the hwcontext will be linear and locally mappable.

  1872. </p></dd>

  1873. <dt><span><samp>instance_extensions</samp></span></dt>

  1874. <dd><p>A plus separated list of additional instance extensions to enable.

  1875. </p></dd>

  1876. <dt><span><samp>device_extensions</samp></span></dt>

  1877. <dd><p>A plus separated list of additional device extensions to enable.

  1878. </p></dd>

  1879. </dl>

  1880. 

  1881. <p>Examples:

  1882. </p><dl compact="compact">

  1883. <dt><span><em>-init_hw_device vulkan:1</em></span></dt>

  1884. <dd><p>Choose the second device on the system.

  1885. </p>

  1886. </dd>

  1887. <dt><span><em>-init_hw_device vulkan:RADV</em></span></dt>

  1888. <dd><p>Choose the first device with a name containing the string <em>RADV</em>.

  1889. </p>

  1890. </dd>

  1891. <dt><span><em>-init_hw_device vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface</em></span></dt>

  1892. <dd><p>Choose the first device and enable the Wayland and XCB instance extensions.

  1893. </p></dd>

  1894. </dl>

  1895. 

  1896. </dd>

  1897. </dl>

  1898. 

  1899. </dd>

  1900. <dt><span><samp>-init_hw_device <var>type</var>[=<var>name</var>]@<var>source</var></samp></span></dt>

  1901. <dd><p>Initialise a new hardware device of type <var>type</var> called <var>name</var>,

  1902. deriving it from the existing device with the name <var>source</var>.

  1903. </p>

  1904. </dd>

  1905. <dt><span><samp>-init_hw_device list</samp></span></dt>

  1906. <dd><p>List all hardware device types supported in this build of ffmpeg.

  1907. </p>

  1908. </dd>

  1909. <dt><span><samp>-filter_hw_device <var>name</var></samp></span></dt>

  1910. <dd><p>Pass the hardware device called <var>name</var> to all filters in any filter graph.

  1911. This can be used to set the device to upload to with the <code>hwupload</code> filter,

  1912. or the device to map to with the <code>hwmap</code> filter.  Other filters may also

  1913. make use of this parameter when they require a hardware device.  Note that this

  1914. is typically only required when the input is not already in hardware frames -

  1915. when it is, filters will derive the device they require from the context of the

  1916. frames they receive as input.

  1917. </p>

  1918. <p>This is a global setting, so all filters will receive the same device.

  1919. </p>

  1920. </dd>

  1921. <dt><span><samp>-hwaccel[:<var>stream_specifier</var>] <var>hwaccel</var> (<em>input,per-stream</em>)</samp></span></dt>

  1922. <dd><p>Use hardware acceleration to decode the matching stream(s). The allowed values

  1923. of <var>hwaccel</var> are:

  1924. </p><dl compact="compact">

  1925. <dt><span><samp>none</samp></span></dt>

  1926. <dd><p>Do not use any hardware acceleration (the default).

  1927. </p>

  1928. </dd>

  1929. <dt><span><samp>auto</samp></span></dt>

  1930. <dd><p>Automatically select the hardware acceleration method.

  1931. </p>

  1932. </dd>

  1933. <dt><span><samp>vdpau</samp></span></dt>

  1934. <dd><p>Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.

  1935. </p>

  1936. </dd>

  1937. <dt><span><samp>dxva2</samp></span></dt>

  1938. <dd><p>Use DXVA2 (DirectX Video Acceleration) hardware acceleration.

  1939. </p>

  1940. </dd>

  1941. <dt><span><samp>d3d11va</samp></span></dt>

  1942. <dd><p>Use D3D11VA (DirectX Video Acceleration) hardware acceleration.

  1943. </p>

  1944. </dd>

  1945. <dt><span><samp>vaapi</samp></span></dt>

  1946. <dd><p>Use VAAPI (Video Acceleration API) hardware acceleration.

  1947. </p>

  1948. </dd>

  1949. <dt><span><samp>qsv</samp></span></dt>

  1950. <dd><p>Use the Intel QuickSync Video acceleration for video transcoding.

  1951. </p>

  1952. <p>Unlike most other values, this option does not enable accelerated decoding (that

  1953. is used automatically whenever a qsv decoder is selected), but accelerated

  1954. transcoding, without copying the frames into the system memory.

  1955. </p>

  1956. <p>For it to work, both the decoder and the encoder must support QSV acceleration

  1957. and no filters must be used.

  1958. </p></dd>

  1959. </dl>

  1960. 

  1961. <p>This option has no effect if the selected hwaccel is not available or not

  1962. supported by the chosen decoder.

  1963. </p>

  1964. <p>Note that most acceleration methods are intended for playback and will not be

  1965. faster than software decoding on modern CPUs. Additionally, <code>ffmpeg</code>

  1966. will usually need to copy the decoded frames from the GPU memory into the system

  1967. memory, resulting in further performance loss. This option is thus mainly

  1968. useful for testing.

  1969. </p>

  1970. </dd>

  1971. <dt><span><samp>-hwaccel_device[:<var>stream_specifier</var>] <var>hwaccel_device</var> (<em>input,per-stream</em>)</samp></span></dt>

  1972. <dd><p>Select a device to use for hardware acceleration.

  1973. </p>

  1974. <p>This option only makes sense when the <samp>-hwaccel</samp> option is also specified.

  1975. It can either refer to an existing device created with <samp>-init_hw_device</samp>

  1976. by name, or it can create a new device as if

  1977. &lsquo;<samp>-init_hw_device</samp>&rsquo; <var>type</var>:<var>hwaccel_device</var>

  1978. were called immediately before.

  1979. </p>

  1980. </dd>

  1981. <dt><span><samp>-hwaccels</samp></span></dt>

  1982. <dd><p>List all hardware acceleration components enabled in this build of ffmpeg.

  1983. Actual runtime availability depends on the hardware and its suitable driver

  1984. being installed.

  1985. </p>

  1986. </dd>

  1987. <dt><span><samp>-fix_sub_duration_heartbeat[:<var>stream_specifier</var>]</samp></span></dt>

  1988. <dd><p>Set a specific output video stream as the heartbeat stream according to which

  1989. to split and push through currently in-progress subtitle upon receipt of a

  1990. random access packet.

  1991. </p>

  1992. <p>This lowers the latency of subtitles for which the end packet or the following

  1993. subtitle has not yet been received. As a drawback, this will most likely lead

  1994. to duplication of subtitle events in order to cover the full duration, so

  1995. when dealing with use cases where latency of when the subtitle event is passed

  1996. on to output is not relevant this option should not be utilized.

  1997. </p>

  1998. <p>Requires <samp>-fix_sub_duration</samp> to be set for the relevant input subtitle

  1999. stream for this to have any effect, as well as for the input subtitle stream

  2000. having to be directly mapped to the same output in which the heartbeat stream

  2001. resides.

  2002. </p>

  2003. </dd>

  2004. </dl>

  2005. 

  2006. <a name="Audio-Options"></a>

  2007. <h3 class="section">5.7 Audio Options<span class="pull-right"><a class="anchor hidden-xs" href="#Audio-Options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Audio-Options" aria-hidden="true">TOC</a></span></h3>

  2008. 

  2009. <dl compact="compact">

  2010. <dt><span><samp>-aframes <var>number</var> (<em>output</em>)</samp></span></dt>

  2011. <dd><p>Set the number of audio frames to output. This is an obsolete alias for

  2012. <code>-frames:a</code>, which you should use instead.

  2013. </p></dd>

  2014. <dt><span><samp>-ar[:<var>stream_specifier</var>] <var>freq</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  2015. <dd><p>Set the audio sampling frequency. For output streams it is set by

  2016. default to the frequency of the corresponding input stream. For input

  2017. streams this option only makes sense for audio grabbing devices and raw

  2018. demuxers and is mapped to the corresponding demuxer options.

  2019. </p></dd>

  2020. <dt><span><samp>-aq <var>q</var> (<em>output</em>)</samp></span></dt>

  2021. <dd><p>Set the audio quality (codec-specific, VBR). This is an alias for -q:a.

  2022. </p></dd>

  2023. <dt><span><samp>-ac[:<var>stream_specifier</var>] <var>channels</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  2024. <dd><p>Set the number of audio channels. For output streams it is set by

  2025. default to the number of input audio channels. For input streams

  2026. this option only makes sense for audio grabbing devices and raw demuxers

  2027. and is mapped to the corresponding demuxer options.

  2028. </p></dd>

  2029. <dt><span><samp>-an (<em>input/output</em>)</samp></span></dt>

  2030. <dd><p>As an input option, blocks all audio streams of a file from being filtered or

  2031. being automatically selected or mapped for any output. See <code>-discard</code>

  2032. option to disable streams individually.

  2033. </p>

  2034. <p>As an output option, disables audio recording i.e. automatic selection or

  2035. mapping of any audio stream. For full manual control see the <code>-map</code>

  2036. option.

  2037. </p></dd>

  2038. <dt><span><samp>-acodec <var>codec</var> (<em>input/output</em>)</samp></span></dt>

  2039. <dd><p>Set the audio codec. This is an alias for <code>-codec:a</code>.

  2040. </p></dd>

  2041. <dt><span><samp>-sample_fmt[:<var>stream_specifier</var>] <var>sample_fmt</var> (<em>output,per-stream</em>)</samp></span></dt>

  2042. <dd><p>Set the audio sample format. Use <code>-sample_fmts</code> to get a list

  2043. of supported sample formats.

  2044. </p>

  2045. </dd>

  2046. <dt><span><samp>-af <var>filtergraph</var> (<em>output</em>)</samp></span></dt>

  2047. <dd><p>Create the filtergraph specified by <var>filtergraph</var> and use it to

  2048. filter the stream.

  2049. </p>

  2050. <p>This is an alias for <code>-filter:a</code>, see the <a href="#filter_005foption">-filter option</a>.

  2051. </p></dd>

  2052. </dl>

  2053. 

  2054. <a name="Advanced-Audio-options"></a>

  2055. <h3 class="section">5.8 Advanced Audio options<span class="pull-right"><a class="anchor hidden-xs" href="#Advanced-Audio-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Advanced-Audio-options" aria-hidden="true">TOC</a></span></h3>

  2056. 

  2057. <dl compact="compact">

  2058. <dt><span><samp>-atag <var>fourcc/tag</var> (<em>output</em>)</samp></span></dt>

  2059. <dd><p>Force audio tag/fourcc. This is an alias for <code>-tag:a</code>.

  2060. </p></dd>

  2061. <dt><span><samp>-absf <var>bitstream_filter</var></samp></span></dt>

  2062. <dd><p>Deprecated, see -bsf

  2063. </p></dd>

  2064. <dt><span><samp>-guess_layout_max <var>channels</var> (<em>input,per-stream</em>)</samp></span></dt>

  2065. <dd><p>If some input channel layout is not known, try to guess only if it

  2066. corresponds to at most the specified number of channels. For example, 2

  2067. tells to <code>ffmpeg</code> to recognize 1 channel as mono and 2 channels as

  2068. stereo but not 6 channels as 5.1. The default is to always try to guess. Use

  2069. 0 to disable all guessing.

  2070. </p></dd>

  2071. </dl>

  2072. 

  2073. <a name="Subtitle-options"></a>

  2074. <h3 class="section">5.9 Subtitle options<span class="pull-right"><a class="anchor hidden-xs" href="#Subtitle-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Subtitle-options" aria-hidden="true">TOC</a></span></h3>

  2075. 

  2076. <dl compact="compact">

  2077. <dt><span><samp>-scodec <var>codec</var> (<em>input/output</em>)</samp></span></dt>

  2078. <dd><p>Set the subtitle codec. This is an alias for <code>-codec:s</code>.

  2079. </p></dd>

  2080. <dt><span><samp>-sn (<em>input/output</em>)</samp></span></dt>

  2081. <dd><p>As an input option, blocks all subtitle streams of a file from being filtered or

  2082. being automatically selected or mapped for any output. See <code>-discard</code>

  2083. option to disable streams individually.

  2084. </p>

  2085. <p>As an output option, disables subtitle recording i.e. automatic selection or

  2086. mapping of any subtitle stream. For full manual control see the <code>-map</code>

  2087. option.

  2088. </p></dd>

  2089. <dt><span><samp>-sbsf <var>bitstream_filter</var></samp></span></dt>

  2090. <dd><p>Deprecated, see -bsf

  2091. </p></dd>

  2092. </dl>

  2093. 

  2094. <a name="Advanced-Subtitle-options"></a>

  2095. <h3 class="section">5.10 Advanced Subtitle options<span class="pull-right"><a class="anchor hidden-xs" href="#Advanced-Subtitle-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Advanced-Subtitle-options" aria-hidden="true">TOC</a></span></h3>

  2096. 

  2097. <dl compact="compact">

  2098. <dt><span><samp>-fix_sub_duration</samp></span></dt>

  2099. <dd><p>Fix subtitles durations. For each subtitle, wait for the next packet in the

  2100. same stream and adjust the duration of the first to avoid overlap. This is

  2101. necessary with some subtitles codecs, especially DVB subtitles, because the

  2102. duration in the original packet is only a rough estimate and the end is

  2103. actually marked by an empty subtitle frame. Failing to use this option when

  2104. necessary can result in exaggerated durations or muxing failures due to

  2105. non-monotonic timestamps.

  2106. </p>

  2107. <p>Note that this option will delay the output of all data until the next

  2108. subtitle packet is decoded: it may increase memory consumption and latency a

  2109. lot.

  2110. </p>

  2111. </dd>

  2112. <dt><span><samp>-canvas_size <var>size</var></samp></span></dt>

  2113. <dd><p>Set the size of the canvas used to render subtitles.

  2114. </p>

  2115. </dd>

  2116. </dl>

  2117. 

  2118. <a name="Advanced-options"></a>

  2119. <h3 class="section">5.11 Advanced options<span class="pull-right"><a class="anchor hidden-xs" href="#Advanced-options" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Advanced-options" aria-hidden="true">TOC</a></span></h3>

  2120. 

  2121. <dl compact="compact">

  2122. <dt><span><samp>-map [-]<var>input_file_id</var>[:<var>stream_specifier</var>][?] | <var>[linklabel]</var> (<em>output</em>)</samp></span></dt>

  2123. <dd>

  2124. <p>Create one or more streams in the output file. This option has two forms for

  2125. specifying the data source(s): the first selects one or more streams from some

  2126. input file (specified with <code>-i</code>), the second takes an output from some

  2127. complex filtergraph (specified with <code>-filter_complex</code> or

  2128. <code>-filter_complex_script</code>).

  2129. </p>

  2130. <p>In the first form, an output stream is created for every stream from the input

  2131. file with the index <var>input_file_id</var>. If <var>stream_specifier</var> is given,

  2132. only those streams that match the specifier are used (see the

  2133. <a href="#Stream-specifiers">Stream specifiers</a> section for the <var>stream_specifier</var> syntax).

  2134. </p>

  2135. <p>A <code>-</code> character before the stream identifier creates a &quot;negative&quot; mapping.

  2136. It disables matching streams from already created mappings.

  2137. </p>

  2138. <p>A trailing <code>?</code> after the stream index will allow the map to be

  2139. optional: if the map matches no streams the map will be ignored instead

  2140. of failing. Note the map will still fail if an invalid input file index

  2141. is used; such as if the map refers to a non-existent input.

  2142. </p>

  2143. <p>An alternative <var>[linklabel]</var> form will map outputs from complex filter

  2144. graphs (see the <samp>-filter_complex</samp> option) to the output file.

  2145. <var>linklabel</var> must correspond to a defined output link label in the graph.

  2146. </p>

  2147. <p>This option may be specified multiple times, each adding more streams to the

  2148. output file. Any given input stream may also be mapped any number of times as a

  2149. source for different output streams, e.g. in order to use different encoding

  2150. options and/or filters. The streams are created in the output in the same order

  2151. in which the <code>-map</code> options are given on the commandline.

  2152. </p>

  2153. <p>Using this option disables the default mappings for this output file.

  2154. </p>

  2155. <p>Examples:

  2156. </p>

  2157. <dl compact="compact">

  2158. <dt><span><em>map everything</em></span></dt>

  2159. <dd><p>To map ALL streams from the first input file to output

  2160. </p><div class="example">

  2161. <pre class="example">ffmpeg -i INPUT -map 0 output

  2162. </pre></div>

  2163. 

  2164. </dd>

  2165. <dt><span><em>select specific stream</em></span></dt>

  2166. <dd><p>If you have two audio streams in the first input file, these streams are

  2167. identified by <var>0:0</var> and <var>0:1</var>. You can use <code>-map</code> to select which

  2168. streams to place in an output file. For example:

  2169. </p><div class="example">

  2170. <pre class="example">ffmpeg -i INPUT -map 0:1 out.wav

  2171. </pre></div>

  2172. <p>will map the second input stream in <samp>INPUT</samp> to the (single) output stream

  2173. in <samp>out.wav</samp>.

  2174. </p>

  2175. </dd>

  2176. <dt><span><em>create multiple streams</em></span></dt>

  2177. <dd><p>To select the stream with index 2 from input file <samp>a.mov</samp> (specified by the

  2178. identifier <var>0:2</var>), and stream with index 6 from input <samp>b.mov</samp>

  2179. (specified by the identifier <var>1:6</var>), and copy them to the output file

  2180. <samp>out.mov</samp>:

  2181. </p><div class="example">

  2182. <pre class="example">ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov

  2183. </pre></div>

  2184. 

  2185. </dd>

  2186. <dt><span><em>create multiple streams 2</em></span></dt>

  2187. <dd><p>To select all video and the third audio stream from an input file:

  2188. </p><div class="example">

  2189. <pre class="example">ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT

  2190. </pre></div>

  2191. 

  2192. </dd>

  2193. <dt><span><em>negative map</em></span></dt>

  2194. <dd><p>To map all the streams except the second audio, use negative mappings

  2195. </p><div class="example">

  2196. <pre class="example">ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT

  2197. </pre></div>

  2198. 

  2199. </dd>

  2200. <dt><span><em>optional map</em></span></dt>

  2201. <dd><p>To map the video and audio streams from the first input, and using the

  2202. trailing <code>?</code>, ignore the audio mapping if no audio streams exist in

  2203. the first input:

  2204. </p><div class="example">

  2205. <pre class="example">ffmpeg -i INPUT -map 0:v -map 0:a? OUTPUT

  2206. </pre></div>

  2207. 

  2208. </dd>

  2209. <dt><span><em>map by language</em></span></dt>

  2210. <dd><p>To pick the English audio stream:

  2211. </p><div class="example">

  2212. <pre class="example">ffmpeg -i INPUT -map 0:m:language:eng OUTPUT

  2213. </pre></div>

  2214. 

  2215. </dd>

  2216. </dl>

  2217. 

  2218. </dd>

  2219. <dt><span><samp>-ignore_unknown</samp></span></dt>

  2220. <dd><p>Ignore input streams with unknown type instead of failing if copying

  2221. such streams is attempted.

  2222. </p>

  2223. </dd>

  2224. <dt><span><samp>-copy_unknown</samp></span></dt>

  2225. <dd><p>Allow input streams with unknown type to be copied instead of failing if copying

  2226. such streams is attempted.

  2227. </p>

  2228. </dd>

  2229. <dt><span><samp>-map_channel [<var>input_file_id</var>.<var>stream_specifier</var>.<var>channel_id</var>|-1][?][:<var>output_file_id</var>.<var>stream_specifier</var>]</samp></span></dt>

  2230. <dd><p>This option is deprecated and will be removed. It can be replaced by the

  2231. <var>pan</var> filter. In some cases it may be easier to use some combination of the

  2232. <var>channelsplit</var>, <var>channelmap</var>, or <var>amerge</var> filters.

  2233. </p>

  2234. <p>Map an audio channel from a given input to an output. If

  2235. <var>output_file_id</var>.<var>stream_specifier</var> is not set, the audio channel will

  2236. be mapped on all the audio streams.

  2237. </p>

  2238. <p>Using &quot;-1&quot; instead of

  2239. <var>input_file_id</var>.<var>stream_specifier</var>.<var>channel_id</var> will map a muted

  2240. channel.

  2241. </p>

  2242. <p>A trailing <code>?</code> will allow the map_channel to be

  2243. optional: if the map_channel matches no channel the map_channel will be ignored instead

  2244. of failing.

  2245. </p>

  2246. <p>For example, assuming <var>INPUT</var> is a stereo audio file, you can switch the

  2247. two audio channels with the following command:

  2248. </p><div class="example">

  2249. <pre class="example">ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT

  2250. </pre></div>

  2251. 

  2252. <p>If you want to mute the first channel and keep the second:

  2253. </p><div class="example">

  2254. <pre class="example">ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT

  2255. </pre></div>

  2256. 

  2257. <p>The order of the &quot;-map_channel&quot; option specifies the order of the channels in

  2258. the output stream. The output channel layout is guessed from the number of

  2259. channels mapped (mono if one &quot;-map_channel&quot;, stereo if two, etc.). Using &quot;-ac&quot;

  2260. in combination of &quot;-map_channel&quot; makes the channel gain levels to be updated if

  2261. input and output channel layouts don&rsquo;t match (for instance two &quot;-map_channel&quot;

  2262. options and &quot;-ac 6&quot;).

  2263. </p>

  2264. <p>You can also extract each channel of an input to specific outputs; the following

  2265. command extracts two channels of the <var>INPUT</var> audio stream (file 0, stream 0)

  2266. to the respective <var>OUTPUT_CH0</var> and <var>OUTPUT_CH1</var> outputs:

  2267. </p><div class="example">

  2268. <pre class="example">ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1

  2269. </pre></div>

  2270. 

  2271. <p>The following example splits the channels of a stereo input into two separate

  2272. streams, which are put into the same output file:

  2273. </p><div class="example">

  2274. <pre class="example">ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg

  2275. </pre></div>

  2276. 

  2277. <p>Note that currently each output stream can only contain channels from a single

  2278. input stream; you can&rsquo;t for example use &quot;-map_channel&quot; to pick multiple input

  2279. audio channels contained in different streams (from the same or different files)

  2280. and merge them into a single output stream. It is therefore not currently

  2281. possible, for example, to turn two separate mono streams into a single stereo

  2282. stream. However splitting a stereo stream into two single channel mono streams

  2283. is possible.

  2284. </p>

  2285. <p>If you need this feature, a possible workaround is to use the <em>amerge</em>

  2286. filter. For example, if you need to merge a media (here <samp>input.mkv</samp>) with 2

  2287. mono audio streams into one single stereo channel audio stream (and keep the

  2288. video stream), you can use the following command:

  2289. </p><div class="example">

  2290. <pre class="example">ffmpeg -i input.mkv -filter_complex &quot;[0:1] [0:2] amerge&quot; -c:a pcm_s16le -c:v copy output.mkv

  2291. </pre></div>

  2292. 

  2293. <p>To map the first two audio channels from the first input, and using the

  2294. trailing <code>?</code>, ignore the audio channel mapping if the first input is

  2295. mono instead of stereo:

  2296. </p><div class="example">

  2297. <pre class="example">ffmpeg -i INPUT -map_channel 0.0.0 -map_channel 0.0.1? OUTPUT

  2298. </pre></div>

  2299. 

  2300. </dd>

  2301. <dt><span><samp>-map_metadata[:<var>metadata_spec_out</var>] <var>infile</var>[:<var>metadata_spec_in</var>] (<em>output,per-metadata</em>)</samp></span></dt>

  2302. <dd><p>Set metadata information of the next output file from <var>infile</var>. Note that

  2303. those are file indices (zero-based), not filenames.

  2304. Optional <var>metadata_spec_in/out</var> parameters specify, which metadata to copy.

  2305. A metadata specifier can have the following forms:

  2306. </p><dl compact="compact">

  2307. <dt><span><samp><var>g</var></samp></span></dt>

  2308. <dd><p>global metadata, i.e. metadata that applies to the whole file

  2309. </p>

  2310. </dd>

  2311. <dt><span><samp><var>s</var>[:<var>stream_spec</var>]</samp></span></dt>

  2312. <dd><p>per-stream metadata. <var>stream_spec</var> is a stream specifier as described

  2313. in the <a href="#Stream-specifiers">Stream specifiers</a> chapter. In an input metadata specifier, the first

  2314. matching stream is copied from. In an output metadata specifier, all matching

  2315. streams are copied to.

  2316. </p>

  2317. </dd>

  2318. <dt><span><samp><var>c</var>:<var>chapter_index</var></samp></span></dt>

  2319. <dd><p>per-chapter metadata. <var>chapter_index</var> is the zero-based chapter index.

  2320. </p>

  2321. </dd>

  2322. <dt><span><samp><var>p</var>:<var>program_index</var></samp></span></dt>

  2323. <dd><p>per-program metadata. <var>program_index</var> is the zero-based program index.

  2324. </p></dd>

  2325. </dl>

  2326. <p>If metadata specifier is omitted, it defaults to global.

  2327. </p>

  2328. <p>By default, global metadata is copied from the first input file,

  2329. per-stream and per-chapter metadata is copied along with streams/chapters. These

  2330. default mappings are disabled by creating any mapping of the relevant type. A negative

  2331. file index can be used to create a dummy mapping that just disables automatic copying.

  2332. </p>

  2333. <p>For example to copy metadata from the first stream of the input file to global metadata

  2334. of the output file:

  2335. </p><div class="example">

  2336. <pre class="example">ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3

  2337. </pre></div>

  2338. 

  2339. <p>To do the reverse, i.e. copy global metadata to all audio streams:

  2340. </p><div class="example">

  2341. <pre class="example">ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv

  2342. </pre></div>

  2343. <p>Note that simple <code>0</code> would work as well in this example, since global

  2344. metadata is assumed by default.

  2345. </p>

  2346. </dd>

  2347. <dt><span><samp>-map_chapters <var>input_file_index</var> (<em>output</em>)</samp></span></dt>

  2348. <dd><p>Copy chapters from input file with index <var>input_file_index</var> to the next

  2349. output file. If no chapter mapping is specified, then chapters are copied from

  2350. the first input file with at least one chapter. Use a negative file index to

  2351. disable any chapter copying.

  2352. </p>

  2353. </dd>

  2354. <dt><span><samp>-benchmark (<em>global</em>)</samp></span></dt>

  2355. <dd><p>Show benchmarking information at the end of an encode.

  2356. Shows real, system and user time used and maximum memory consumption.

  2357. Maximum memory consumption is not supported on all systems,

  2358. it will usually display as 0 if not supported.

  2359. </p></dd>

  2360. <dt><span><samp>-benchmark_all (<em>global</em>)</samp></span></dt>

  2361. <dd><p>Show benchmarking information during the encode.

  2362. Shows real, system and user time used in various steps (audio/video encode/decode).

  2363. </p></dd>

  2364. <dt><span><samp>-timelimit <var>duration</var> (<em>global</em>)</samp></span></dt>

  2365. <dd><p>Exit after ffmpeg has been running for <var>duration</var> seconds in CPU user time.

  2366. </p></dd>

  2367. <dt><span><samp>-dump (<em>global</em>)</samp></span></dt>

  2368. <dd><p>Dump each input packet to stderr.

  2369. </p></dd>

  2370. <dt><span><samp>-hex (<em>global</em>)</samp></span></dt>

  2371. <dd><p>When dumping packets, also dump the payload.

  2372. </p></dd>

  2373. <dt><span><samp>-readrate <var>speed</var> (<em>input</em>)</samp></span></dt>

  2374. <dd><p>Limit input read speed.

  2375. </p>

  2376. <p>Its value is a floating-point positive number which represents the maximum duration of

  2377. media, in seconds, that should be ingested in one second of wallclock time.

  2378. Default value is zero and represents no imposed limitation on speed of ingestion.

  2379. Value <code>1</code> represents real-time speed and is equivalent to <code>-re</code>.

  2380. </p>

  2381. <p>Mainly used to simulate a capture device or live input stream (e.g. when reading from a file).

  2382. Should not be used with a low value when input is an actual capture device or live stream as

  2383. it may cause packet loss.

  2384. </p>

  2385. <p>It is useful for when flow speed of output packets is important, such as live streaming.

  2386. </p></dd>

  2387. <dt><span><samp>-re (<em>input</em>)</samp></span></dt>

  2388. <dd><p>Read input at native frame rate. This is equivalent to setting <code>-readrate 1</code>.

  2389. </p></dd>

  2390. <dt><span><samp>-vsync <var>parameter</var> (<em>global</em>)</samp></span></dt>

  2391. <dt><span><samp>-fps_mode[:<var>stream_specifier</var>] <var>parameter</var> (<em>output,per-stream</em>)</samp></span></dt>

  2392. <dd><p>Set video sync method / framerate mode. vsync is applied to all output video streams

  2393. but can be overridden for a stream by setting fps_mode. vsync is deprecated and will be

  2394. removed in the future.

  2395. </p>

  2396. <p>For compatibility reasons some of the values for vsync can be specified as numbers (shown

  2397. in parentheses in the following table).

  2398. </p>

  2399. <dl compact="compact">

  2400. <dt><span><samp>passthrough (0)</samp></span></dt>

  2401. <dd><p>Each frame is passed with its timestamp from the demuxer to the muxer.

  2402. </p></dd>

  2403. <dt><span><samp>cfr (1)</samp></span></dt>

  2404. <dd><p>Frames will be duplicated and dropped to achieve exactly the requested

  2405. constant frame rate.

  2406. </p></dd>

  2407. <dt><span><samp>vfr (2)</samp></span></dt>

  2408. <dd><p>Frames are passed through with their timestamp or dropped so as to

  2409. prevent 2 frames from having the same timestamp.

  2410. </p></dd>

  2411. <dt><span><samp>drop</samp></span></dt>

  2412. <dd><p>As passthrough but destroys all timestamps, making the muxer generate

  2413. fresh timestamps based on frame-rate.

  2414. </p></dd>

  2415. <dt><span><samp>auto (-1)</samp></span></dt>

  2416. <dd><p>Chooses between cfr and vfr depending on muxer capabilities. This is the

  2417. default method.

  2418. </p></dd>

  2419. </dl>

  2420. 

  2421. <p>Note that the timestamps may be further modified by the muxer, after this.

  2422. For example, in the case that the format option <samp>avoid_negative_ts</samp>

  2423. is enabled.

  2424. </p>

  2425. <p>With -map you can select from which stream the timestamps should be

  2426. taken. You can leave either video or audio unchanged and sync the

  2427. remaining stream(s) to the unchanged one.

  2428. </p>

  2429. </dd>

  2430. <dt><span><samp>-frame_drop_threshold <var>parameter</var></samp></span></dt>

  2431. <dd><p>Frame drop threshold, which specifies how much behind video frames can

  2432. be before they are dropped. In frame rate units, so 1.0 is one frame.

  2433. The default is -1.1. One possible usecase is to avoid framedrops in case

  2434. of noisy timestamps or to increase frame drop precision in case of exact

  2435. timestamps.

  2436. </p>

  2437. </dd>

  2438. <dt><span><samp>-adrift_threshold <var>time</var></samp></span></dt>

  2439. <dd><p>Set the minimum difference between timestamps and audio data (in seconds) to trigger

  2440. adding/dropping samples to make it match the timestamps. This option effectively is

  2441. a threshold to select between hard (add/drop) and soft (squeeze/stretch) compensation.

  2442. <code>-async</code> must be set to a positive value.

  2443. </p>

  2444. </dd>

  2445. <dt><span><samp>-apad <var>parameters</var> (<em>output,per-stream</em>)</samp></span></dt>

  2446. <dd><p>Pad the output audio stream(s). This is the same as applying <code>-af apad</code>.

  2447. Argument is a string of filter parameters composed the same as with the <code>apad</code> filter.

  2448. <code>-shortest</code> must be set for this output for the option to take effect.

  2449. </p>

  2450. </dd>

  2451. <dt><span><samp>-copyts</samp></span></dt>

  2452. <dd><p>Do not process input timestamps, but keep their values without trying

  2453. to sanitize them. In particular, do not remove the initial start time

  2454. offset value.

  2455. </p>

  2456. <p>Note that, depending on the <samp>vsync</samp> option or on specific muxer

  2457. processing (e.g. in case the format option <samp>avoid_negative_ts</samp>

  2458. is enabled) the output timestamps may mismatch with the input

  2459. timestamps even when this option is selected.

  2460. </p>

  2461. </dd>

  2462. <dt><span><samp>-start_at_zero</samp></span></dt>

  2463. <dd><p>When used with <samp>copyts</samp>, shift input timestamps so they start at zero.

  2464. </p>

  2465. <p>This means that using e.g. <code>-ss 50</code> will make output timestamps start at

  2466. 50 seconds, regardless of what timestamp the input file started at.

  2467. </p>

  2468. </dd>

  2469. <dt><span><samp>-copytb <var>mode</var></samp></span></dt>

  2470. <dd><p>Specify how to set the encoder timebase when stream copying.  <var>mode</var> is an

  2471. integer numeric value, and can assume one of the following values:

  2472. </p>

  2473. <dl compact="compact">

  2474. <dt><span><samp>1</samp></span></dt>

  2475. <dd><p>Use the demuxer timebase.

  2476. </p>

  2477. <p>The time base is copied to the output encoder from the corresponding input

  2478. demuxer. This is sometimes required to avoid non monotonically increasing

  2479. timestamps when copying video streams with variable frame rate.

  2480. </p>

  2481. </dd>

  2482. <dt><span><samp>0</samp></span></dt>

  2483. <dd><p>Use the decoder timebase.

  2484. </p>

  2485. <p>The time base is copied to the output encoder from the corresponding input

  2486. decoder.

  2487. </p>

  2488. </dd>

  2489. <dt><span><samp>-1</samp></span></dt>

  2490. <dd><p>Try to make the choice automatically, in order to generate a sane output.

  2491. </p></dd>

  2492. </dl>

  2493. 

  2494. <p>Default value is -1.

  2495. </p>

  2496. </dd>

  2497. <dt><span><samp>-enc_time_base[:<var>stream_specifier</var>] <var>timebase</var> (<em>output,per-stream</em>)</samp></span></dt>

  2498. <dd><p>Set the encoder timebase. <var>timebase</var> is a floating point number,

  2499. and can assume one of the following values:

  2500. </p>

  2501. <dl compact="compact">

  2502. <dt><span><samp>0</samp></span></dt>

  2503. <dd><p>Assign a default value according to the media type.

  2504. </p>

  2505. <p>For video - use 1/framerate, for audio - use 1/samplerate.

  2506. </p>

  2507. </dd>

  2508. <dt><span><samp>-1</samp></span></dt>

  2509. <dd><p>Use the input stream timebase when possible.

  2510. </p>

  2511. <p>If an input stream is not available, the default timebase will be used.

  2512. </p>

  2513. </dd>

  2514. <dt><span><samp>&gt;0</samp></span></dt>

  2515. <dd><p>Use the provided number as the timebase.

  2516. </p>

  2517. <p>This field can be provided as a ratio of two integers (e.g. 1:24, 1:48000)

  2518. or as a floating point number (e.g. 0.04166, 2.0833e-5)

  2519. </p></dd>

  2520. </dl>

  2521. 

  2522. <p>Default value is 0.

  2523. </p>

  2524. </dd>

  2525. <dt><span><samp>-bitexact (<em>input/output</em>)</samp></span></dt>

  2526. <dd><p>Enable bitexact mode for (de)muxer and (de/en)coder

  2527. </p></dd>

  2528. <dt><span><samp>-shortest (<em>output</em>)</samp></span></dt>

  2529. <dd><p>Finish encoding when the shortest output stream ends.

  2530. </p>

  2531. <p>Note that this option may require buffering frames, which introduces extra

  2532. latency. The maximum amount of this latency may be controlled with the

  2533. <code>-shortest_buf_duration</code> option.

  2534. </p>

  2535. </dd>

  2536. <dt><span><samp>-shortest_buf_duration <var>duration</var> (<em>output</em>)</samp></span></dt>

  2537. <dd><p>The <code>-shortest</code> option may require buffering potentially large amounts

  2538. of data when at least one of the streams is &quot;sparse&quot; (i.e. has large gaps

  2539. between frames – this is typically the case for subtitles).

  2540. </p>

  2541. <p>This option controls the maximum duration of buffered frames in seconds.

  2542. Larger values may allow the <code>-shortest</code> option to produce more accurate

  2543. results, but increase memory use and latency.

  2544. </p>

  2545. <p>The default value is 10 seconds.

  2546. </p>

  2547. </dd>

  2548. <dt><span><samp>-dts_delta_threshold <var>threshold</var></samp></span></dt>

  2549. <dd><p>Timestamp discontinuity delta threshold, expressed as a decimal number

  2550. of seconds.

  2551. </p>

  2552. <p>The timestamp discontinuity correction enabled by this option is only

  2553. applied to input formats accepting timestamp discontinuity (for which

  2554. the <code>AV_FMT_DISCONT</code> flag is enabled), e.g. MPEG-TS and HLS, and

  2555. is automatically disabled when employing the <code>-copy_ts</code> option

  2556. (unless wrapping is detected).

  2557. </p>

  2558. <p>If a timestamp discontinuity is detected whose absolute value is

  2559. greater than <var>threshold</var>, ffmpeg will remove the discontinuity by

  2560. decreasing/increasing the current DTS and PTS by the corresponding

  2561. delta value.

  2562. </p>

  2563. <p>The default value is 10.

  2564. </p>

  2565. </dd>

  2566. <dt><span><samp>-dts_error_threshold <var>threshold</var></samp></span></dt>

  2567. <dd><p>Timestamp error delta threshold, expressed as a decimal number of

  2568. seconds.

  2569. </p>

  2570. <p>The timestamp correction enabled by this option is only applied to

  2571. input formats not accepting timestamp discontinuity (for which the

  2572. <code>AV_FMT_DISCONT</code> flag is not enabled).

  2573. </p>

  2574. <p>If a timestamp discontinuity is detected whose absolute value is

  2575. greater than <var>threshold</var>, ffmpeg will drop the PTS/DTS timestamp

  2576. value.

  2577. </p>

  2578. <p>The default value is <code>3600*30</code> (30 hours), which is arbitrarily

  2579. picked and quite conservative.

  2580. </p>

  2581. </dd>

  2582. <dt><span><samp>-muxdelay <var>seconds</var> (<em>output</em>)</samp></span></dt>

  2583. <dd><p>Set the maximum demux-decode delay.

  2584. </p></dd>

  2585. <dt><span><samp>-muxpreload <var>seconds</var> (<em>output</em>)</samp></span></dt>

  2586. <dd><p>Set the initial demux-decode delay.

  2587. </p></dd>

  2588. <dt><span><samp>-streamid <var>output-stream-index</var>:<var>new-value</var> (<em>output</em>)</samp></span></dt>

  2589. <dd><p>Assign a new stream-id value to an output stream. This option should be

  2590. specified prior to the output filename to which it applies.

  2591. For the situation where multiple output files exist, a streamid

  2592. may be reassigned to a different value.

  2593. </p>

  2594. <p>For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for

  2595. an output mpegts file:

  2596. </p><div class="example">

  2597. <pre class="example">ffmpeg -i inurl -streamid 0:33 -streamid 1:36 out.ts

  2598. </pre></div>

  2599. 

  2600. </dd>

  2601. <dt><span><samp>-bsf[:<var>stream_specifier</var>] <var>bitstream_filters</var> (<em>output,per-stream</em>)</samp></span></dt>

  2602. <dd><p>Set bitstream filters for matching streams. <var>bitstream_filters</var> is

  2603. a comma-separated list of bitstream filters. Use the <code>-bsfs</code> option

  2604. to get the list of bitstream filters.

  2605. </p><div class="example">

  2606. <pre class="example">ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264

  2607. </pre></div>

  2608. <div class="example">

  2609. <pre class="example">ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt

  2610. </pre></div>

  2611. 

  2612. </dd>

  2613. <dt><span><samp>-tag[:<var>stream_specifier</var>] <var>codec_tag</var> (<em>input/output,per-stream</em>)</samp></span></dt>

  2614. <dd><p>Force a tag/fourcc for matching streams.

  2615. </p>

  2616. </dd>

  2617. <dt><span><samp>-timecode <var>hh</var>:<var>mm</var>:<var>ss</var>SEP<var>ff</var></samp></span></dt>

  2618. <dd><p>Specify Timecode for writing. <var>SEP</var> is &rsquo;:&rsquo; for non drop timecode and &rsquo;;&rsquo;

  2619. (or &rsquo;.&rsquo;) for drop.

  2620. </p><div class="example">

  2621. <pre class="example">ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg

  2622. </pre></div>

  2623. 

  2624. <span id="filter_005fcomplex_005foption"></span></dd>

  2625. <dt><span><samp>-filter_complex <var>filtergraph</var> (<em>global</em>)</samp></span></dt>

  2626. <dd><p>Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or

  2627. outputs. For simple graphs &ndash; those with one input and one output of the same

  2628. type &ndash; see the <samp>-filter</samp> options. <var>filtergraph</var> is a description of

  2629. the filtergraph, as described in the &ldquo;Filtergraph syntax&rdquo; section of the

  2630. ffmpeg-filters manual.

  2631. </p>

  2632. <p>Input link labels must refer to input streams using the

  2633. <code>[file_index:stream_specifier]</code> syntax (i.e. the same as <samp>-map</samp>

  2634. uses). If <var>stream_specifier</var> matches multiple streams, the first one will be

  2635. used. An unlabeled input will be connected to the first unused input stream of

  2636. the matching type.

  2637. </p>

  2638. <p>Output link labels are referred to with <samp>-map</samp>. Unlabeled outputs are

  2639. added to the first output file.

  2640. </p>

  2641. <p>Note that with this option it is possible to use only lavfi sources without

  2642. normal input files.

  2643. </p>

  2644. <p>For example, to overlay an image over video

  2645. </p><div class="example">

  2646. <pre class="example">ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map

  2647. '[out]' out.mkv

  2648. </pre></div>

  2649. <p>Here <code>[0:v]</code> refers to the first video stream in the first input file,

  2650. which is linked to the first (main) input of the overlay filter. Similarly the

  2651. first video stream in the second input is linked to the second (overlay) input

  2652. of overlay.

  2653. </p>

  2654. <p>Assuming there is only one video stream in each input file, we can omit input

  2655. labels, so the above is equivalent to

  2656. </p><div class="example">

  2657. <pre class="example">ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map

  2658. '[out]' out.mkv

  2659. </pre></div>

  2660. 

  2661. <p>Furthermore we can omit the output label and the single output from the filter

  2662. graph will be added to the output file automatically, so we can simply write

  2663. </p><div class="example">

  2664. <pre class="example">ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv

  2665. </pre></div>

  2666. 

  2667. <p>As a special exception, you can use a bitmap subtitle stream as input: it

  2668. will be converted into a video with the same size as the largest video in

  2669. the file, or 720x576 if no video is present. Note that this is an

  2670. experimental and temporary solution. It will be removed once libavfilter has

  2671. proper support for subtitles.

  2672. </p>

  2673. <p>For example, to hardcode subtitles on top of a DVB-T recording stored in

  2674. MPEG-TS format, delaying the subtitles by 1 second:

  2675. </p><div class="example">

  2676. <pre class="example">ffmpeg -i input.ts -filter_complex \

  2677.   '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \

  2678.   -sn -map '#0x2dc' output.mkv

  2679. </pre></div>

  2680. <p>(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,

  2681. audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)

  2682. </p>

  2683. <p>To generate 5 seconds of pure red video using lavfi <code>color</code> source:

  2684. </p><div class="example">

  2685. <pre class="example">ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv

  2686. </pre></div>

  2687. 

  2688. </dd>

  2689. <dt><span><samp>-filter_complex_threads <var>nb_threads</var> (<em>global</em>)</samp></span></dt>

  2690. <dd><p>Defines how many threads are used to process a filter_complex graph.

  2691. Similar to filter_threads but used for <code>-filter_complex</code> graphs only.

  2692. The default is the number of available CPUs.

  2693. </p>

  2694. </dd>

  2695. <dt><span><samp>-lavfi <var>filtergraph</var> (<em>global</em>)</samp></span></dt>

  2696. <dd><p>Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or

  2697. outputs. Equivalent to <samp>-filter_complex</samp>.

  2698. </p>

  2699. </dd>

  2700. <dt><span><samp>-filter_complex_script <var>filename</var> (<em>global</em>)</samp></span></dt>

  2701. <dd><p>This option is similar to <samp>-filter_complex</samp>, the only difference is that

  2702. its argument is the name of the file from which a complex filtergraph

  2703. description is to be read.

  2704. </p>

  2705. </dd>

  2706. <dt><span><samp>-accurate_seek (<em>input</em>)</samp></span></dt>

  2707. <dd><p>This option enables or disables accurate seeking in input files with the

  2708. <samp>-ss</samp> option. It is enabled by default, so seeking is accurate when

  2709. transcoding. Use <samp>-noaccurate_seek</samp> to disable it, which may be useful

  2710. e.g. when copying some streams and transcoding the others.

  2711. </p>

  2712. </dd>

  2713. <dt><span><samp>-seek_timestamp (<em>input</em>)</samp></span></dt>

  2714. <dd><p>This option enables or disables seeking by timestamp in input files with the

  2715. <samp>-ss</samp> option. It is disabled by default. If enabled, the argument

  2716. to the <samp>-ss</samp> option is considered an actual timestamp, and is not

  2717. offset by the start time of the file. This matters only for files which do

  2718. not start from timestamp 0, such as transport streams.

  2719. </p>

  2720. </dd>

  2721. <dt><span><samp>-thread_queue_size <var>size</var> (<em>input/output</em>)</samp></span></dt>

  2722. <dd><p>For input, this option sets the maximum number of queued packets when reading

  2723. from the file or device. With low latency / high rate live streams, packets may

  2724. be discarded if they are not read in a timely manner; setting this value can

  2725. force ffmpeg to use a separate input thread and read packets as soon as they

  2726. arrive. By default ffmpeg only does this if multiple inputs are specified.

  2727. </p>

  2728. <p>For output, this option specified the maximum number of packets that may be

  2729. queued to each muxing thread.

  2730. </p>

  2731. </dd>

  2732. <dt><span><samp>-sdp_file <var>file</var> (<em>global</em>)</samp></span></dt>

  2733. <dd><p>Print sdp information for an output stream to <var>file</var>.

  2734. This allows dumping sdp information when at least one output isn&rsquo;t an

  2735. rtp stream. (Requires at least one of the output formats to be rtp).

  2736. </p>

  2737. </dd>

  2738. <dt><span><samp>-discard (<em>input</em>)</samp></span></dt>

  2739. <dd><p>Allows discarding specific streams or frames from streams.

  2740. Any input stream can be fully discarded, using value <code>all</code> whereas

  2741. selective discarding of frames from a stream occurs at the demuxer

  2742. and is not supported by all demuxers.

  2743. </p>

  2744. <dl compact="compact">

  2745. <dt><span><samp>none</samp></span></dt>

  2746. <dd><p>Discard no frame.

  2747. </p>

  2748. </dd>

  2749. <dt><span><samp>default</samp></span></dt>

  2750. <dd><p>Default, which discards no frames.

  2751. </p>

  2752. </dd>

  2753. <dt><span><samp>noref</samp></span></dt>

  2754. <dd><p>Discard all non-reference frames.

  2755. </p>

  2756. </dd>

  2757. <dt><span><samp>bidir</samp></span></dt>

  2758. <dd><p>Discard all bidirectional frames.

  2759. </p>

  2760. </dd>

  2761. <dt><span><samp>nokey</samp></span></dt>

  2762. <dd><p>Discard all frames excepts keyframes.

  2763. </p>

  2764. </dd>

  2765. <dt><span><samp>all</samp></span></dt>

  2766. <dd><p>Discard all frames.

  2767. </p></dd>

  2768. </dl>

  2769. 

  2770. </dd>

  2771. <dt><span><samp>-abort_on <var>flags</var> (<em>global</em>)</samp></span></dt>

  2772. <dd><p>Stop and abort on various conditions. The following flags are available:

  2773. </p>

  2774. <dl compact="compact">

  2775. <dt><span><samp>empty_output</samp></span></dt>

  2776. <dd><p>No packets were passed to the muxer, the output is empty.

  2777. </p></dd>

  2778. <dt><span><samp>empty_output_stream</samp></span></dt>

  2779. <dd><p>No packets were passed to the muxer in some of the output streams.

  2780. </p></dd>

  2781. </dl>

  2782. 

  2783. </dd>

  2784. <dt><span><samp>-max_error_rate (<em>global</em>)</samp></span></dt>

  2785. <dd><p>Set fraction of decoding frame failures across all inputs which when crossed

  2786. ffmpeg will return exit code 69. Crossing this threshold does not terminate

  2787. processing. Range is a floating-point number between 0 to 1. Default is 2/3.

  2788. </p>

  2789. </dd>

  2790. <dt><span><samp>-xerror (<em>global</em>)</samp></span></dt>

  2791. <dd><p>Stop and exit on error

  2792. </p>

  2793. </dd>

  2794. <dt><span><samp>-max_muxing_queue_size <var>packets</var> (<em>output,per-stream</em>)</samp></span></dt>

  2795. <dd><p>When transcoding audio and/or video streams, ffmpeg will not begin writing into

  2796. the output until it has one packet for each such stream. While waiting for that

  2797. to happen, packets for other streams are buffered. This option sets the size of

  2798. this buffer, in packets, for the matching output stream.

  2799. </p>

  2800. <p>The default value of this option should be high enough for most uses, so only

  2801. touch this option if you are sure that you need it.

  2802. </p>

  2803. </dd>

  2804. <dt><span><samp>-muxing_queue_data_threshold <var>bytes</var> (<em>output,per-stream</em>)</samp></span></dt>

  2805. <dd><p>This is a minimum threshold until which the muxing queue size is not taken into

  2806. account. Defaults to 50 megabytes per stream, and is based on the overall size

  2807. of packets passed to the muxer.

  2808. </p>

  2809. </dd>

  2810. <dt><span><samp>-auto_conversion_filters (<em>global</em>)</samp></span></dt>

  2811. <dd><p>Enable automatically inserting format conversion filters in all filter

  2812. graphs, including those defined by <samp>-vf</samp>, <samp>-af</samp>,

  2813. <samp>-filter_complex</samp> and <samp>-lavfi</samp>. If filter format negotiation

  2814. requires a conversion, the initialization of the filters will fail.

  2815. Conversions can still be performed by inserting the relevant conversion

  2816. filter (scale, aresample) in the graph.

  2817. On by default, to explicitly disable it you need to specify

  2818. <code>-noauto_conversion_filters</code>.

  2819. </p>

  2820. </dd>

  2821. <dt><span><samp>-bits_per_raw_sample[:<var>stream_specifier</var>] <var>value</var> (<em>output,per-stream</em>)</samp></span></dt>

  2822. <dd><p>Declare the number of bits per raw sample in the given output stream to be

  2823. <var>value</var>. Note that this option sets the information provided to the

  2824. encoder/muxer, it does not change the stream to conform to this value. Setting

  2825. values that do not match the stream properties may result in encoding failures

  2826. or invalid output files.

  2827. </p>

  2828. </dd>

  2829. <dt><span><samp>-stats_enc_pre[:<var>stream_specifier</var>] <var>path</var> (<em>output,per-stream</em>)</samp></span></dt>

  2830. <dt><span><samp>-stats_enc_post[:<var>stream_specifier</var>] <var>path</var> (<em>output,per-stream</em>)</samp></span></dt>

  2831. <dt><span><samp>-stats_mux_pre[:<var>stream_specifier</var>] <var>path</var> (<em>output,per-stream</em>)</samp></span></dt>

  2832. <dd><p>Write per-frame encoding information about the matching streams into the file

  2833. given by <var>path</var>.

  2834. </p>

  2835. <p><samp>-stats_enc_pre</samp> writes information about raw video or audio frames right

  2836. before they are sent for encoding, while <samp>-stats_enc_post</samp> writes

  2837. information about encoded packets as they are received from the encoder.

  2838. <samp>-stats_mux_pre</samp> writes information about packets just as they are about to

  2839. be sent to the muxer. Every frame or packet produces one line in the specified

  2840. file. The format of this line is controlled by <samp>-stats_enc_pre_fmt</samp> /

  2841. <samp>-stats_enc_post_fmt</samp> / <samp>-stats_mux_pre_fmt</samp>.

  2842. </p>

  2843. <p>When stats for multiple streams are written into a single file, the lines

  2844. corresponding to different streams will be interleaved. The precise order of

  2845. this interleaving is not specified and not guaranteed to remain stable between

  2846. different invocations of the program, even with the same options.

  2847. </p>

  2848. </dd>

  2849. <dt><span><samp>-stats_enc_pre_fmt[:<var>stream_specifier</var>] <var>format_spec</var> (<em>output,per-stream</em>)</samp></span></dt>

  2850. <dt><span><samp>-stats_enc_post_fmt[:<var>stream_specifier</var>] <var>format_spec</var> (<em>output,per-stream</em>)</samp></span></dt>

  2851. <dt><span><samp>-stats_mux_pre_fmt[:<var>stream_specifier</var>] <var>format_spec</var> (<em>output,per-stream</em>)</samp></span></dt>

  2852. <dd><p>Specify the format for the lines written with <samp>-stats_enc_pre</samp> /

  2853. <samp>-stats_enc_post</samp> / <samp>-stats_mux_pre</samp>.

  2854. </p>

  2855. <p><var>format_spec</var> is a string that may contain directives of the form

  2856. <var>{fmt}</var>. <var>format_spec</var> is backslash-escaped &mdash; use \{, \}, and \\

  2857. to write a literal {, }, or \, respectively, into the output.

  2858. </p>

  2859. <p>The directives given with <var>fmt</var> may be one of the following:

  2860. </p><dl compact="compact">

  2861. <dt><span><samp>fidx</samp></span></dt>

  2862. <dd><p>Index of the output file.

  2863. </p>

  2864. </dd>

  2865. <dt><span><samp>sidx</samp></span></dt>

  2866. <dd><p>Index of the output stream in the file.

  2867. </p>

  2868. </dd>

  2869. <dt><span><samp>n</samp></span></dt>

  2870. <dd><p>Frame number. Pre-encoding: number of frames sent to the encoder so far.

  2871. Post-encoding: number of packets received from the encoder so far.

  2872. Muxing: number of packets submitted to the muxer for this stream so far.

  2873. </p>

  2874. </dd>

  2875. <dt><span><samp>ni</samp></span></dt>

  2876. <dd><p>Input frame number. Index of the input frame (i.e. output by a decoder) that

  2877. corresponds to this output frame or packet. -1 if unavailable.

  2878. </p>

  2879. </dd>

  2880. <dt><span><samp>tb</samp></span></dt>

  2881. <dd><p>Encoder timebase, as a rational number <var>num/den</var>. Note that this may be

  2882. different from the timebase used by the muxer.

  2883. </p>

  2884. </dd>

  2885. <dt><span><samp>tbi</samp></span></dt>

  2886. <dd><p>Timebase for <var>ptsi</var>, as a rational number <var>num/den</var>. Available when

  2887. <var>ptsi</var> is available, <var>0/1</var> otherwise.

  2888. </p>

  2889. </dd>

  2890. <dt><span><samp>pts</samp></span></dt>

  2891. <dd><p>Presentation timestamp of the frame or packet, as an integer. Should be

  2892. multiplied by the timebase to compute presentation time.

  2893. </p>

  2894. </dd>

  2895. <dt><span><samp>ptsi</samp></span></dt>

  2896. <dd><p>Presentation timestamp of the input frame (see <var>ni</var>), as an integer. Should

  2897. be multiplied by <var>tbi</var> to compute presentation time. Printed as

  2898. (2^63 - 1 = 9223372036854775807) when not available.

  2899. </p>

  2900. </dd>

  2901. <dt><span><samp>t</samp></span></dt>

  2902. <dd><p>Presentation time of the frame or packet, as a decimal number. Equal to

  2903. <var>pts</var> multiplied by <var>tb</var>.

  2904. </p>

  2905. </dd>

  2906. <dt><span><samp>ti</samp></span></dt>

  2907. <dd><p>Presentation time of the input frame (see <var>ni</var>), as a decimal number. Equal

  2908. to <var>ptsi</var> multiplied by <var>tbi</var>. Printed as inf when not available.

  2909. </p>

  2910. </dd>

  2911. <dt><span><samp>dts</samp></span></dt>

  2912. <dd><p>Decoding timestamp of the packet, as an integer. Should be multiplied by the

  2913. timebase to compute presentation time. Post-encoding only.

  2914. </p>

  2915. </dd>

  2916. <dt><span><samp>dt</samp></span></dt>

  2917. <dd><p>Decoding time of the frame or packet, as a decimal number. Equal to

  2918. <var>dts</var> multiplied by <var>tb</var>.

  2919. </p>

  2920. </dd>

  2921. <dt><span><samp>sn</samp></span></dt>

  2922. <dd><p>Number of audio samples sent to the encoder so far. Audio and pre-encoding only.

  2923. </p>

  2924. </dd>

  2925. <dt><span><samp>samp</samp></span></dt>

  2926. <dd><p>Number of audio samples in the frame. Audio and pre-encoding only.

  2927. </p>

  2928. </dd>

  2929. <dt><span><samp>size</samp></span></dt>

  2930. <dd><p>Size of the encoded packet in bytes. Post-encoding only.

  2931. </p>

  2932. </dd>

  2933. <dt><span><samp>br</samp></span></dt>

  2934. <dd><p>Current bitrate in bits per second. Post-encoding only.

  2935. </p>

  2936. </dd>

  2937. <dt><span><samp>abr</samp></span></dt>

  2938. <dd><p>Average bitrate for the whole stream so far, in bits per second, -1 if it cannot

  2939. be determined at this point. Post-encoding only.

  2940. </p></dd>

  2941. </dl>

  2942. 

  2943. <p>The default format strings are:

  2944. </p><dl compact="compact">

  2945. <dt><span><samp>pre-encoding</samp></span></dt>

  2946. <dd><p>{fidx} {sidx} {n} {t}

  2947. </p></dd>

  2948. <dt><span><samp>post-encoding</samp></span></dt>

  2949. <dd><p>{fidx} {sidx} {n} {t}

  2950. </p></dd>

  2951. </dl>

  2952. <p>In the future, new items may be added to the end of the default formatting

  2953. strings. Users who depend on the format staying exactly the same, should

  2954. prescribe it manually.

  2955. </p>

  2956. <p>Note that stats for different streams written into the same file may have

  2957. different formats.

  2958. </p>

  2959. </dd>

  2960. </dl>

  2961. 

  2962. <a name="Preset-files"></a>

  2963. <h3 class="section">5.12 Preset files<span class="pull-right"><a class="anchor hidden-xs" href="#Preset-files" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Preset-files" aria-hidden="true">TOC</a></span></h3>

  2964. <p>A preset file contains a sequence of <var>option</var>=<var>value</var> pairs,

  2965. one for each line, specifying a sequence of options which would be

  2966. awkward to specify on the command line. Lines starting with the hash

  2967. (&rsquo;#&rsquo;) character are ignored and are used to provide comments. Check

  2968. the <samp>presets</samp> directory in the FFmpeg source tree for examples.

  2969. </p>

  2970. <p>There are two types of preset files: ffpreset and avpreset files.

  2971. </p>

  2972. <a name="ffpreset-files"></a>

  2973. <h4 class="subsection">5.12.1 ffpreset files<span class="pull-right"><a class="anchor hidden-xs" href="#ffpreset-files" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-ffpreset-files" aria-hidden="true">TOC</a></span></h4>

  2974. <p>ffpreset files are specified with the <code>vpre</code>, <code>apre</code>,

  2975. <code>spre</code>, and <code>fpre</code> options. The <code>fpre</code> option takes the

  2976. filename of the preset instead of a preset name as input and can be

  2977. used for any kind of codec. For the <code>vpre</code>, <code>apre</code>, and

  2978. <code>spre</code> options, the options specified in a preset file are

  2979. applied to the currently selected codec of the same type as the preset

  2980. option.

  2981. </p>

  2982. <p>The argument passed to the <code>vpre</code>, <code>apre</code>, and <code>spre</code>

  2983. preset options identifies the preset file to use according to the

  2984. following rules:

  2985. </p>

  2986. <p>First ffmpeg searches for a file named <var>arg</var>.ffpreset in the

  2987. directories <samp>$FFMPEG_DATADIR</samp> (if set), and <samp>$HOME/.ffmpeg</samp>, and in

  2988. the datadir defined at configuration time (usually <samp>PREFIX/share/ffmpeg</samp>)

  2989. or in a <samp>ffpresets</samp> folder along the executable on win32,

  2990. in that order. For example, if the argument is <code>libvpx-1080p</code>, it will

  2991. search for the file <samp>libvpx-1080p.ffpreset</samp>.

  2992. </p>

  2993. <p>If no such file is found, then ffmpeg will search for a file named

  2994. <var>codec_name</var>-<var>arg</var>.ffpreset in the above-mentioned

  2995. directories, where <var>codec_name</var> is the name of the codec to which

  2996. the preset file options will be applied. For example, if you select

  2997. the video codec with <code>-vcodec libvpx</code> and use <code>-vpre 1080p</code>,

  2998. then it will search for the file <samp>libvpx-1080p.ffpreset</samp>.

  2999. </p>

  3000. <a name="avpreset-files"></a>

  3001. <h4 class="subsection">5.12.2 avpreset files<span class="pull-right"><a class="anchor hidden-xs" href="#avpreset-files" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-avpreset-files" aria-hidden="true">TOC</a></span></h4>

  3002. <p>avpreset files are specified with the <code>pre</code> option. They work similar to

  3003. ffpreset files, but they only allow encoder- specific options. Therefore, an

  3004. <var>option</var>=<var>value</var> pair specifying an encoder cannot be used.

  3005. </p>

  3006. <p>When the <code>pre</code> option is specified, ffmpeg will look for files with the

  3007. suffix .avpreset in the directories <samp>$AVCONV_DATADIR</samp> (if set), and

  3008. <samp>$HOME/.avconv</samp>, and in the datadir defined at configuration time (usually

  3009. <samp>PREFIX/share/ffmpeg</samp>), in that order.

  3010. </p>

  3011. <p>First ffmpeg searches for a file named <var>codec_name</var>-<var>arg</var>.avpreset in

  3012. the above-mentioned directories, where <var>codec_name</var> is the name of the codec

  3013. to which the preset file options will be applied. For example, if you select the

  3014. video codec with <code>-vcodec libvpx</code> and use <code>-pre 1080p</code>, then it will

  3015. search for the file <samp>libvpx-1080p.avpreset</samp>.

  3016. </p>

  3017. <p>If no such file is found, then ffmpeg will search for a file named

  3018. <var>arg</var>.avpreset in the same directories.

  3019. </p>

  3020. 

  3021. <a name="Examples-1"></a>

  3022. <h2 class="chapter">6 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-1" aria-hidden="true">TOC</a></span></h2>

  3023. 

  3024. <a name="Video-and-Audio-grabbing"></a>

  3025. <h3 class="section">6.1 Video and Audio grabbing<span class="pull-right"><a class="anchor hidden-xs" href="#Video-and-Audio-grabbing" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-and-Audio-grabbing" aria-hidden="true">TOC</a></span></h3>

  3026. 

  3027. <p>If you specify the input format and device then ffmpeg can grab video

  3028. and audio directly.

  3029. </p>

  3030. <div class="example">

  3031. <pre class="example">ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg

  3032. </pre></div>

  3033. 

  3034. <p>Or with an ALSA audio source (mono input, card id 1) instead of OSS:

  3035. </p><div class="example">

  3036. <pre class="example">ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg

  3037. </pre></div>

  3038. 

  3039. <p>Note that you must activate the right video source and channel before

  3040. launching ffmpeg with any TV viewer such as

  3041. <a href="http://linux.bytesex.org/xawtv/">xawtv</a> by Gerd Knorr. You also

  3042. have to set the audio recording levels correctly with a

  3043. standard mixer.

  3044. </p>

  3045. <a name="X11-grabbing"></a>

  3046. <h3 class="section">6.2 X11 grabbing<span class="pull-right"><a class="anchor hidden-xs" href="#X11-grabbing" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-X11-grabbing" aria-hidden="true">TOC</a></span></h3>

  3047. 

  3048. <p>Grab the X11 display with ffmpeg via

  3049. </p>

  3050. <div class="example">

  3051. <pre class="example">ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg

  3052. </pre></div>

  3053. 

  3054. <p>0.0 is display.screen number of your X11 server, same as

  3055. the DISPLAY environment variable.

  3056. </p>

  3057. <div class="example">

  3058. <pre class="example">ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg

  3059. </pre></div>

  3060. 

  3061. <p>0.0 is display.screen number of your X11 server, same as the DISPLAY environment

  3062. variable. 10 is the x-offset and 20 the y-offset for the grabbing.

  3063. </p>

  3064. <a name="Video-and-Audio-file-format-conversion"></a>

  3065. <h3 class="section">6.3 Video and Audio file format conversion<span class="pull-right"><a class="anchor hidden-xs" href="#Video-and-Audio-file-format-conversion" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Video-and-Audio-file-format-conversion" aria-hidden="true">TOC</a></span></h3>

  3066. 

  3067. <p>Any supported file format and protocol can serve as input to ffmpeg:

  3068. </p>

  3069. <p>Examples:

  3070. </p><ul>

  3071. <li> You can use YUV files as input:

  3072. 

  3073. <div class="example">

  3074. <pre class="example">ffmpeg -i /tmp/test%d.Y /tmp/out.mpg

  3075. </pre></div>

  3076. 

  3077. <p>It will use the files:

  3078. </p><div class="example">

  3079. <pre class="example">/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,

  3080. /tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...

  3081. </pre></div>

  3082. 

  3083. <p>The Y files use twice the resolution of the U and V files. They are

  3084. raw files, without header. They can be generated by all decent video

  3085. decoders. You must specify the size of the image with the <samp>-s</samp> option

  3086. if ffmpeg cannot guess it.

  3087. </p>

  3088. </li><li> You can input from a raw YUV420P file:

  3089. 

  3090. <div class="example">

  3091. <pre class="example">ffmpeg -i /tmp/test.yuv /tmp/out.avi

  3092. </pre></div>

  3093. 

  3094. <p>test.yuv is a file containing raw YUV planar data. Each frame is composed

  3095. of the Y plane followed by the U and V planes at half vertical and

  3096. horizontal resolution.

  3097. </p>

  3098. </li><li> You can output to a raw YUV420P file:

  3099. 

  3100. <div class="example">

  3101. <pre class="example">ffmpeg -i mydivx.avi hugefile.yuv

  3102. </pre></div>

  3103. 

  3104. </li><li> You can set several input files and output files:

  3105. 

  3106. <div class="example">

  3107. <pre class="example">ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg

  3108. </pre></div>

  3109. 

  3110. <p>Converts the audio file a.wav and the raw YUV video file a.yuv

  3111. to MPEG file a.mpg.

  3112. </p>

  3113. </li><li> You can also do audio and video conversions at the same time:

  3114. 

  3115. <div class="example">

  3116. <pre class="example">ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2

  3117. </pre></div>

  3118. 

  3119. <p>Converts a.wav to MPEG audio at 22050 Hz sample rate.

  3120. </p>

  3121. </li><li> You can encode to several formats at the same time and define a

  3122. mapping from input stream to output streams:

  3123. 

  3124. <div class="example">

  3125. <pre class="example">ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2

  3126. </pre></div>

  3127. 

  3128. <p>Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. &rsquo;-map

  3129. file:index&rsquo; specifies which input stream is used for each output

  3130. stream, in the order of the definition of output streams.

  3131. </p>

  3132. </li><li> You can transcode decrypted VOBs:

  3133. 

  3134. <div class="example">

  3135. <pre class="example">ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi

  3136. </pre></div>

  3137. 

  3138. <p>This is a typical DVD ripping example; the input is a VOB file, the

  3139. output an AVI file with MPEG-4 video and MP3 audio. Note that in this

  3140. command we use B-frames so the MPEG-4 stream is DivX5 compatible, and

  3141. GOP size is 300 which means one intra frame every 10 seconds for 29.97fps

  3142. input video. Furthermore, the audio stream is MP3-encoded so you need

  3143. to enable LAME support by passing <code>--enable-libmp3lame</code> to configure.

  3144. The mapping is particularly useful for DVD transcoding

  3145. to get the desired audio language.

  3146. </p>

  3147. <p>NOTE: To see the supported input formats, use <code>ffmpeg -demuxers</code>.

  3148. </p>

  3149. </li><li> You can extract images from a video, or create a video from many images:

  3150. 

  3151. <p>For extracting images from a video:

  3152. </p><div class="example">

  3153. <pre class="example">ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg

  3154. </pre></div>

  3155. 

  3156. <p>This will extract one video frame per second from the video and will

  3157. output them in files named <samp>foo-001.jpeg</samp>, <samp>foo-002.jpeg</samp>,

  3158. etc. Images will be rescaled to fit the new WxH values.

  3159. </p>

  3160. <p>If you want to extract just a limited number of frames, you can use the

  3161. above command in combination with the <code>-frames:v</code> or <code>-t</code> option,

  3162. or in combination with -ss to start extracting from a certain point in time.

  3163. </p>

  3164. <p>For creating a video from many images:

  3165. </p><div class="example">

  3166. <pre class="example">ffmpeg -f image2 -framerate 12 -i foo-%03d.jpeg -s WxH foo.avi

  3167. </pre></div>

  3168. 

  3169. <p>The syntax <code>foo-%03d.jpeg</code> specifies to use a decimal number

  3170. composed of three digits padded with zeroes to express the sequence

  3171. number. It is the same syntax supported by the C printf function, but

  3172. only formats accepting a normal integer are suitable.

  3173. </p>

  3174. <p>When importing an image sequence, -i also supports expanding

  3175. shell-like wildcard patterns (globbing) internally, by selecting the

  3176. image2-specific <code>-pattern_type glob</code> option.

  3177. </p>

  3178. <p>For example, for creating a video from filenames matching the glob pattern

  3179. <code>foo-*.jpeg</code>:

  3180. </p><div class="example">

  3181. <pre class="example">ffmpeg -f image2 -pattern_type glob -framerate 12 -i 'foo-*.jpeg' -s WxH foo.avi

  3182. </pre></div>

  3183. 

  3184. </li><li> You can put many streams of the same type in the output:

  3185. 

  3186. <div class="example">

  3187. <pre class="example">ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut

  3188. </pre></div>

  3189. 

  3190. <p>The resulting output file <samp>test12.nut</samp> will contain the first four streams

  3191. from the input files in reverse order.

  3192. </p>

  3193. </li><li> To force CBR video output:

  3194. <div class="example">

  3195. <pre class="example">ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v

  3196. </pre></div>

  3197. 

  3198. </li><li> The four options lmin, lmax, mblmin and mblmax use &rsquo;lambda&rsquo; units,

  3199. but you may use the QP2LAMBDA constant to easily convert from &rsquo;q&rsquo; units:

  3200. <div class="example">

  3201. <pre class="example">ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext

  3202. </pre></div>

  3203. 

  3204. </li></ul>

  3205. 

  3206. 

  3207. <a name="See-Also"></a>

  3208. <h2 class="chapter">7 See Also<span class="pull-right"><a class="anchor hidden-xs" href="#See-Also" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-See-Also" aria-hidden="true">TOC</a></span></h2>

  3209. 

  3210. <p><a href="ffmpeg-all.html">ffmpeg-all</a>,

  3211. <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>,

  3212. <a href="ffmpeg-utils.html">ffmpeg-utils</a>,

  3213. <a href="ffmpeg-scaler.html">ffmpeg-scaler</a>,

  3214. <a href="ffmpeg-resampler.html">ffmpeg-resampler</a>,

  3215. <a href="ffmpeg-codecs.html">ffmpeg-codecs</a>,

  3216. <a href="ffmpeg-bitstream-filters.html">ffmpeg-bitstream-filters</a>,

  3217. <a href="ffmpeg-formats.html">ffmpeg-formats</a>,

  3218. <a href="ffmpeg-devices.html">ffmpeg-devices</a>,

  3219. <a href="ffmpeg-protocols.html">ffmpeg-protocols</a>,

  3220. <a href="ffmpeg-filters.html">ffmpeg-filters</a>

  3221. </p>

  3222. 

  3223. <a name="Authors"></a>

  3224. <h2 class="chapter">8 Authors<span class="pull-right"><a class="anchor hidden-xs" href="#Authors" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Authors" aria-hidden="true">TOC</a></span></h2>

  3225. 

  3226. <p>The FFmpeg developers.

  3227. </p>

  3228. <p>For details about the authorship, see the Git history of the project

  3229. (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command

  3230. <code>git log</code> in the FFmpeg source directory, or browsing the

  3231. online repository at <a href="https://git.ffmpeg.org/ffmpeg">https://git.ffmpeg.org/ffmpeg</a>.

  3232. </p>

  3233. <p>Maintainers for the specific components are listed in the file

  3234. <samp>MAINTAINERS</samp> in the source code tree.

  3235. </p>

  3236. 

  3237.       <p style="font-size: small;">

  3238.         This document was generated using <a href="https://www.gnu.org/software/texinfo/"><em>makeinfo</em></a>.

  3239.       </p>

  3240.     </div>

  3241.   </body>

  3242. </html>