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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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  5.     <meta charset="utf-8">

  6.     <title>

  7.       FFmpeg Devices Documentation

  8.     </title>

  9.     <meta name="viewport" content="width=device-width,initial-scale=1.0">

  10.     <link rel="stylesheet" type="text/css" href="bootstrap.min.css">

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  13.   <body>

  14.     <div class="container">

  15.       <h1>

  16.       FFmpeg Devices 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-Description" href="#Description">1 Description</a></li>

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

  32.   <li><a id="toc-Input-Devices" href="#Input-Devices">3 Input Devices</a>

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

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

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

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

  37.     </ul></li>

  38.     <li><a id="toc-android_005fcamera" href="#android_005fcamera">3.2 android_camera</a>

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

  40.       <li><a id="toc-Options-1" href="#Options-1">3.2.1 Options</a></li>

  41.     </ul></li>

  42.     <li><a id="toc-avfoundation" href="#avfoundation">3.3 avfoundation</a>

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

  44.       <li><a id="toc-Options-2" href="#Options-2">3.3.1 Options</a></li>

  45.       <li><a id="toc-Examples" href="#Examples">3.3.2 Examples</a></li>

  46.     </ul></li>

  47.     <li><a id="toc-bktr" href="#bktr">3.4 bktr</a>

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

  49.       <li><a id="toc-Options-3" href="#Options-3">3.4.1 Options</a></li>

  50.     </ul></li>

  51.     <li><a id="toc-decklink" href="#decklink">3.5 decklink</a>

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

  53.       <li><a id="toc-Options-4" href="#Options-4">3.5.1 Options</a></li>

  54.       <li><a id="toc-Examples-1" href="#Examples-1">3.5.2 Examples</a></li>

  55.     </ul></li>

  56.     <li><a id="toc-dshow" href="#dshow">3.6 dshow</a>

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

  58.       <li><a id="toc-Options-5" href="#Options-5">3.6.1 Options</a></li>

  59.       <li><a id="toc-Examples-2" href="#Examples-2">3.6.2 Examples</a></li>

  60.     </ul></li>

  61.     <li><a id="toc-fbdev" href="#fbdev">3.7 fbdev</a>

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

  63.       <li><a id="toc-Options-6" href="#Options-6">3.7.1 Options</a></li>

  64.     </ul></li>

  65.     <li><a id="toc-gdigrab" href="#gdigrab">3.8 gdigrab</a>

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

  67.       <li><a id="toc-Options-7" href="#Options-7">3.8.1 Options</a></li>

  68.     </ul></li>

  69.     <li><a id="toc-iec61883" href="#iec61883">3.9 iec61883</a>

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

  71.       <li><a id="toc-Options-8" href="#Options-8">3.9.1 Options</a></li>

  72.       <li><a id="toc-Examples-3" href="#Examples-3">3.9.2 Examples</a></li>

  73.     </ul></li>

  74.     <li><a id="toc-jack" href="#jack">3.10 jack</a>

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

  76.       <li><a id="toc-Options-9" href="#Options-9">3.10.1 Options</a></li>

  77.     </ul></li>

  78.     <li><a id="toc-kmsgrab" href="#kmsgrab">3.11 kmsgrab</a>

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

  80.       <li><a id="toc-Options-10" href="#Options-10">3.11.1 Options</a></li>

  81.       <li><a id="toc-Examples-4" href="#Examples-4">3.11.2 Examples</a></li>

  82.     </ul></li>

  83.     <li><a id="toc-lavfi" href="#lavfi">3.12 lavfi</a>

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

  85.       <li><a id="toc-Options-11" href="#Options-11">3.12.1 Options</a></li>

  86.       <li><a id="toc-Examples-5" href="#Examples-5">3.12.2 Examples</a></li>

  87.     </ul></li>

  88.     <li><a id="toc-libcdio" href="#libcdio">3.13 libcdio</a>

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

  90.       <li><a id="toc-Options-12" href="#Options-12">3.13.1 Options</a></li>

  91.     </ul></li>

  92.     <li><a id="toc-libdc1394" href="#libdc1394">3.14 libdc1394</a>

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

  94.       <li><a id="toc-Options-13" href="#Options-13">3.14.1 Options</a></li>

  95.     </ul></li>

  96.     <li><a id="toc-openal" href="#openal">3.15 openal</a>

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

  98.       <li><a id="toc-Options-14" href="#Options-14">3.15.1 Options</a></li>

  99.       <li><a id="toc-Examples-6" href="#Examples-6">3.15.2 Examples</a></li>

  100.     </ul></li>

  101.     <li><a id="toc-oss" href="#oss">3.16 oss</a>

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

  103.       <li><a id="toc-Options-15" href="#Options-15">3.16.1 Options</a></li>

  104.     </ul></li>

  105.     <li><a id="toc-pulse" href="#pulse">3.17 pulse</a>

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

  107.       <li><a id="toc-Options-16" href="#Options-16">3.17.1 Options</a></li>

  108.       <li><a id="toc-Examples-7" href="#Examples-7">3.17.2 Examples</a></li>

  109.     </ul></li>

  110.     <li><a id="toc-sndio" href="#sndio">3.18 sndio</a>

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

  112.       <li><a id="toc-Options-17" href="#Options-17">3.18.1 Options</a></li>

  113.     </ul></li>

  114.     <li><a id="toc-video4linux2_002c-v4l2" href="#video4linux2_002c-v4l2">3.19 video4linux2, v4l2</a>

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

  116.       <li><a id="toc-Options-18" href="#Options-18">3.19.1 Options</a></li>

  117.     </ul></li>

  118.     <li><a id="toc-vfwcap" href="#vfwcap">3.20 vfwcap</a>

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

  120.       <li><a id="toc-Options-19" href="#Options-19">3.20.1 Options</a></li>

  121.     </ul></li>

  122.     <li><a id="toc-x11grab" href="#x11grab">3.21 x11grab</a>

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

  124.       <li><a id="toc-Options-20" href="#Options-20">3.21.1 Options</a></li>

  125.     </ul></li>

  126.   </ul></li>

  127.   <li><a id="toc-Output-Devices" href="#Output-Devices">4 Output Devices</a>

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

  129.     <li><a id="toc-alsa-1" href="#alsa-1">4.1 alsa</a>

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

  131.       <li><a id="toc-Examples-8" href="#Examples-8">4.1.1 Examples</a></li>

  132.     </ul></li>

  133.     <li><a id="toc-AudioToolbox" href="#AudioToolbox">4.2 AudioToolbox</a>

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

  135.       <li><a id="toc-Options-21" href="#Options-21">4.2.1 Options</a></li>

  136.       <li><a id="toc-Examples-9" href="#Examples-9">4.2.2 Examples</a></li>

  137.     </ul></li>

  138.     <li><a id="toc-caca" href="#caca">4.3 caca</a>

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

  140.       <li><a id="toc-Options-22" href="#Options-22">4.3.1 Options</a></li>

  141.       <li><a id="toc-Examples-10" href="#Examples-10">4.3.2 Examples</a></li>

  142.     </ul></li>

  143.     <li><a id="toc-decklink-1" href="#decklink-1">4.4 decklink</a>

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

  145.       <li><a id="toc-Options-23" href="#Options-23">4.4.1 Options</a></li>

  146.       <li><a id="toc-Examples-11" href="#Examples-11">4.4.2 Examples</a></li>

  147.     </ul></li>

  148.     <li><a id="toc-fbdev-1" href="#fbdev-1">4.5 fbdev</a>

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

  150.       <li><a id="toc-Options-24" href="#Options-24">4.5.1 Options</a></li>

  151.       <li><a id="toc-Examples-12" href="#Examples-12">4.5.2 Examples</a></li>

  152.     </ul></li>

  153.     <li><a id="toc-opengl" href="#opengl">4.6 opengl</a>

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

  155.       <li><a id="toc-Options-25" href="#Options-25">4.6.1 Options</a></li>

  156.       <li><a id="toc-Examples-13" href="#Examples-13">4.6.2 Examples</a></li>

  157.     </ul></li>

  158.     <li><a id="toc-oss-1" href="#oss-1">4.7 oss</a></li>

  159.     <li><a id="toc-pulse-1" href="#pulse-1">4.8 pulse</a>

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

  161.       <li><a id="toc-Options-26" href="#Options-26">4.8.1 Options</a></li>

  162.       <li><a id="toc-Examples-14" href="#Examples-14">4.8.2 Examples</a></li>

  163.     </ul></li>

  164.     <li><a id="toc-sdl" href="#sdl">4.9 sdl</a>

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

  166.       <li><a id="toc-Options-27" href="#Options-27">4.9.1 Options</a></li>

  167.       <li><a id="toc-Interactive-commands" href="#Interactive-commands">4.9.2 Interactive commands</a></li>

  168.       <li><a id="toc-Examples-15" href="#Examples-15">4.9.3 Examples</a></li>

  169.     </ul></li>

  170.     <li><a id="toc-sndio-1" href="#sndio-1">4.10 sndio</a></li>

  171.     <li><a id="toc-v4l2" href="#v4l2">4.11 v4l2</a></li>

  172.     <li><a id="toc-xv" href="#xv">4.12 xv</a>

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

  174.       <li><a id="toc-Options-28" href="#Options-28">4.12.1 Options</a></li>

  175.       <li><a id="toc-Examples-16" href="#Examples-16">4.12.2 Examples</a></li>

  176.     </ul></li>

  177.   </ul></li>

  178.   <li><a id="toc-See-Also" href="#See-Also">5 See Also</a></li>

  179.   <li><a id="toc-Authors" href="#Authors">6 Authors</a></li>

  180. </ul>

  181. </div>

  182. </div>

  183. 

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

  185. <h2 class="chapter">1 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>

  186. 

  187. <p>This document describes the input and output devices provided by the

  188. libavdevice library.

  189. </p>

  190. 

  191. <a name="Device-Options"></a>

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

  193. 

  194. <p>The libavdevice library provides the same interface as

  195. libavformat. Namely, an input device is considered like a demuxer, and

  196. an output device like a muxer, and the interface and generic device

  197. options are the same provided by libavformat (see the ffmpeg-formats

  198. manual).

  199. </p>

  200. <p>In addition each input or output device may support so-called private

  201. options, which are specific for that component.

  202. </p>

  203. <p>Options may be set by specifying -<var>option</var> <var>value</var> in the

  204. FFmpeg tools, or by setting the value explicitly in the device

  205. <code>AVFormatContext</code> options or using the <samp>libavutil/opt.h</samp> API

  206. for programmatic use.

  207. </p>

  208. 

  209. <a name="Input-Devices"></a>

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

  211. 

  212. <p>Input devices are configured elements in FFmpeg which enable accessing

  213. the data coming from a multimedia device attached to your system.

  214. </p>

  215. <p>When you configure your FFmpeg build, all the supported input devices

  216. are enabled by default. You can list all available ones using the

  217. configure option &quot;&ndash;list-indevs&quot;.

  218. </p>

  219. <p>You can disable all the input devices using the configure option

  220. &quot;&ndash;disable-indevs&quot;, and selectively enable an input device using the

  221. option &quot;&ndash;enable-indev=<var>INDEV</var>&quot;, or you can disable a particular

  222. input device using the option &quot;&ndash;disable-indev=<var>INDEV</var>&quot;.

  223. </p>

  224. <p>The option &quot;-devices&quot; of the ff* tools will display the list of

  225. supported input devices.

  226. </p>

  227. <p>A description of the currently available input devices follows.

  228. </p>

  229. <a name="alsa"></a>

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

  231. 

  232. <p>ALSA (Advanced Linux Sound Architecture) input device.

  233. </p>

  234. <p>To enable this input device during configuration you need libasound

  235. installed on your system.

  236. </p>

  237. <p>This device allows capturing from an ALSA device. The name of the

  238. device to capture has to be an ALSA card identifier.

  239. </p>

  240. <p>An ALSA identifier has the syntax:

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

  242. <pre class="example">hw:<var>CARD</var>[,<var>DEV</var>[,<var>SUBDEV</var>]]

  243. </pre></div>

  244. 

  245. <p>where the <var>DEV</var> and <var>SUBDEV</var> components are optional.

  246. </p>

  247. <p>The three arguments (in order: <var>CARD</var>,<var>DEV</var>,<var>SUBDEV</var>)

  248. specify card number or identifier, device number and subdevice number

  249. (-1 means any).

  250. </p>

  251. <p>To see the list of cards currently recognized by your system check the

  252. files <samp>/proc/asound/cards</samp> and <samp>/proc/asound/devices</samp>.

  253. </p>

  254. <p>For example to capture with <code>ffmpeg</code> from an ALSA device with

  255. card id 0, you may run the command:

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

  257. <pre class="example">ffmpeg -f alsa -i hw:0 alsaout.wav

  258. </pre></div>

  259. 

  260. <p>For more information see:

  261. <a href="http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html">http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html</a>

  262. </p>

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

  264. <h4 class="subsection">3.1.1 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></h4>

  265. 

  266. <dl compact="compact">

  267. <dt><span><samp>sample_rate</samp></span></dt>

  268. <dd><p>Set the sample rate in Hz. Default is 48000.

  269. </p>

  270. </dd>

  271. <dt><span><samp>channels</samp></span></dt>

  272. <dd><p>Set the number of channels. Default is 2.

  273. </p>

  274. </dd>

  275. </dl>

  276. 

  277. <a name="android_005fcamera"></a>

  278. <h3 class="section">3.2 android_camera<span class="pull-right"><a class="anchor hidden-xs" href="#android_005fcamera" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-android_005fcamera" aria-hidden="true">TOC</a></span></h3>

  279. 

  280. <p>Android camera input device.

  281. </p>

  282. <p>This input devices uses the Android Camera2 NDK API which is

  283. available on devices with API level 24+. The availability of

  284. android_camera is autodetected during configuration.

  285. </p>

  286. <p>This device allows capturing from all cameras on an Android device,

  287. which are integrated into the Camera2 NDK API.

  288. </p>

  289. <p>The available cameras are enumerated internally and can be selected

  290. with the <var>camera_index</var> parameter. The input file string is

  291. discarded.

  292. </p>

  293. <p>Generally the back facing camera has index 0 while the front facing

  294. camera has index 1.

  295. </p>

  296. <a name="Options-1"></a>

  297. <h4 class="subsection">3.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-1" aria-hidden="true">TOC</a></span></h4>

  298. 

  299. <dl compact="compact">

  300. <dt><span><samp>video_size</samp></span></dt>

  301. <dd><p>Set the video size given as a string such as 640x480 or hd720.

  302. Falls back to the first available configuration reported by

  303. Android if requested video size is not available or by default.

  304. </p>

  305. </dd>

  306. <dt><span><samp>framerate</samp></span></dt>

  307. <dd><p>Set the video framerate.

  308. Falls back to the first available configuration reported by

  309. Android if requested framerate is not available or by default (-1).

  310. </p>

  311. </dd>

  312. <dt><span><samp>camera_index</samp></span></dt>

  313. <dd><p>Set the index of the camera to use. Default is 0.

  314. </p>

  315. </dd>

  316. <dt><span><samp>input_queue_size</samp></span></dt>

  317. <dd><p>Set the maximum number of frames to buffer. Default is 5.

  318. </p>

  319. </dd>

  320. </dl>

  321. 

  322. <a name="avfoundation"></a>

  323. <h3 class="section">3.3 avfoundation<span class="pull-right"><a class="anchor hidden-xs" href="#avfoundation" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-avfoundation" aria-hidden="true">TOC</a></span></h3>

  324. 

  325. <p>AVFoundation input device.

  326. </p>

  327. <p>AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX &gt;= 10.7 as well as on iOS.

  328. </p>

  329. <p>The input filename has to be given in the following syntax:

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

  331. <pre class="example">-i &quot;[[VIDEO]:[AUDIO]]&quot;

  332. </pre></div>

  333. <p>The first entry selects the video input while the latter selects the audio input.

  334. The stream has to be specified by the device name or the device index as shown by the device list.

  335. Alternatively, the video and/or audio input device can be chosen by index using the

  336. <samp>

  337.     -video_device_index &lt;INDEX&gt;

  338. </samp>

  339. and/or

  340. <samp>

  341.     -audio_device_index &lt;INDEX&gt;

  342. </samp>

  343. , overriding any

  344. device name or index given in the input filename.

  345. </p>

  346. <p>All available devices can be enumerated by using <samp>-list_devices true</samp>, listing

  347. all device names and corresponding indices.

  348. </p>

  349. <p>There are two device name aliases:

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

  351. <dt><span><code>default</code></span></dt>

  352. <dd><p>Select the AVFoundation default device of the corresponding type.

  353. </p>

  354. </dd>

  355. <dt><span><code>none</code></span></dt>

  356. <dd><p>Do not record the corresponding media type.

  357. This is equivalent to specifying an empty device name or index.

  358. </p>

  359. </dd>

  360. </dl>

  361. 

  362. <a name="Options-2"></a>

  363. <h4 class="subsection">3.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-2" aria-hidden="true">TOC</a></span></h4>

  364. 

  365. <p>AVFoundation supports the following options:

  366. </p>

  367. <dl compact="compact">

  368. <dt><span><samp>-list_devices &lt;TRUE|FALSE&gt;</samp></span></dt>

  369. <dd><p>If set to true, a list of all available input devices is given showing all

  370. device names and indices.

  371. </p>

  372. </dd>

  373. <dt><span><samp>-video_device_index &lt;INDEX&gt;</samp></span></dt>

  374. <dd><p>Specify the video device by its index. Overrides anything given in the input filename.

  375. </p>

  376. </dd>

  377. <dt><span><samp>-audio_device_index &lt;INDEX&gt;</samp></span></dt>

  378. <dd><p>Specify the audio device by its index. Overrides anything given in the input filename.

  379. </p>

  380. </dd>

  381. <dt><span><samp>-pixel_format &lt;FORMAT&gt;</samp></span></dt>

  382. <dd><p>Request the video device to use a specific pixel format.

  383. If the specified format is not supported, a list of available formats is given

  384. and the first one in this list is used instead. Available pixel formats are:

  385. <code>monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,

  386.  bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,

  387.  yuv420p, nv12, yuyv422, gray</code>

  388. </p>

  389. </dd>

  390. <dt><span><samp>-framerate</samp></span></dt>

  391. <dd><p>Set the grabbing frame rate. Default is <code>ntsc</code>, corresponding to a

  392. frame rate of <code>30000/1001</code>.

  393. </p>

  394. </dd>

  395. <dt><span><samp>-video_size</samp></span></dt>

  396. <dd><p>Set the video frame size.

  397. </p>

  398. </dd>

  399. <dt><span><samp>-capture_cursor</samp></span></dt>

  400. <dd><p>Capture the mouse pointer. Default is 0.

  401. </p>

  402. </dd>

  403. <dt><span><samp>-capture_mouse_clicks</samp></span></dt>

  404. <dd><p>Capture the screen mouse clicks. Default is 0.

  405. </p>

  406. </dd>

  407. <dt><span><samp>-capture_raw_data</samp></span></dt>

  408. <dd><p>Capture the raw device data. Default is 0.

  409. Using this option may result in receiving the underlying data delivered to the AVFoundation framework. E.g. for muxed devices that sends raw DV data to the framework (like tape-based camcorders), setting this option to false results in extracted video frames captured in the designated pixel format only. Setting this option to true results in receiving the raw DV stream untouched.

  410. </p></dd>

  411. </dl>

  412. 

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

  414. <h4 class="subsection">3.3.2 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></h4>

  415. 

  416. <ul>

  417. <li> Print the list of AVFoundation supported devices and exit:

  418. <div class="example">

  419. <pre class="example">$ ffmpeg -f avfoundation -list_devices true -i &quot;&quot;

  420. </pre></div>

  421. 

  422. </li><li> Record video from video device 0 and audio from audio device 0 into out.avi:

  423. <div class="example">

  424. <pre class="example">$ ffmpeg -f avfoundation -i &quot;0:0&quot; out.avi

  425. </pre></div>

  426. 

  427. </li><li> Record video from video device 2 and audio from audio device 1 into out.avi:

  428. <div class="example">

  429. <pre class="example">$ ffmpeg -f avfoundation -video_device_index 2 -i &quot;:1&quot; out.avi

  430. </pre></div>

  431. 

  432. </li><li> Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:

  433. <div class="example">

  434. <pre class="example">$ ffmpeg -f avfoundation -pixel_format bgr0 -i &quot;default:none&quot; out.avi

  435. </pre></div>

  436. 

  437. </li><li> Record raw DV data from a suitable input device and write the output into out.dv:

  438. <div class="example">

  439. <pre class="example">$ ffmpeg -f avfoundation -capture_raw_data true -i &quot;zr100:none&quot; out.dv

  440. </pre></div>

  441. 

  442. 

  443. </li></ul>

  444. 

  445. <a name="bktr"></a>

  446. <h3 class="section">3.4 bktr<span class="pull-right"><a class="anchor hidden-xs" href="#bktr" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-bktr" aria-hidden="true">TOC</a></span></h3>

  447. 

  448. <p>BSD video input device.

  449. </p>

  450. <a name="Options-3"></a>

  451. <h4 class="subsection">3.4.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-3" aria-hidden="true">TOC</a></span></h4>

  452. 

  453. <dl compact="compact">

  454. <dt><span><samp>framerate</samp></span></dt>

  455. <dd><p>Set the frame rate.

  456. </p>

  457. </dd>

  458. <dt><span><samp>video_size</samp></span></dt>

  459. <dd><p>Set the video frame size. Default is <code>vga</code>.

  460. </p>

  461. </dd>

  462. <dt><span><samp>standard</samp></span></dt>

  463. <dd>

  464. <p>Available values are:

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

  466. <dt><span>&lsquo;<samp>pal</samp>&rsquo;</span></dt>

  467. <dt><span>&lsquo;<samp>ntsc</samp>&rsquo;</span></dt>

  468. <dt><span>&lsquo;<samp>secam</samp>&rsquo;</span></dt>

  469. <dt><span>&lsquo;<samp>paln</samp>&rsquo;</span></dt>

  470. <dt><span>&lsquo;<samp>palm</samp>&rsquo;</span></dt>

  471. <dt><span>&lsquo;<samp>ntscj</samp>&rsquo;</span></dt>

  472. </dl>

  473. 

  474. </dd>

  475. </dl>

  476. 

  477. <a name="decklink"></a>

  478. <h3 class="section">3.5 decklink<span class="pull-right"><a class="anchor hidden-xs" href="#decklink" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-decklink" aria-hidden="true">TOC</a></span></h3>

  479. 

  480. <p>The decklink input device provides capture capabilities for Blackmagic

  481. DeckLink devices.

  482. </p>

  483. <p>To enable this input device, you need the Blackmagic DeckLink SDK and you

  484. need to configure with the appropriate <code>--extra-cflags</code>

  485. and <code>--extra-ldflags</code>.

  486. On Windows, you need to run the IDL files through <code>widl</code>.

  487. </p>

  488. <p>DeckLink is very picky about the formats it supports. Pixel format of the

  489. input can be set with <samp>raw_format</samp>.

  490. Framerate and video size must be determined for your device with

  491. <code>-list_formats 1</code>. Audio sample rate is always 48 kHz and the number

  492. of channels can be 2, 8 or 16. Note that all audio channels are bundled in one single

  493. audio track.

  494. </p>

  495. <a name="Options-4"></a>

  496. <h4 class="subsection">3.5.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-4" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-4" aria-hidden="true">TOC</a></span></h4>

  497. 

  498. <dl compact="compact">

  499. <dt><span><samp>list_devices</samp></span></dt>

  500. <dd><p>If set to <samp>true</samp>, print a list of devices and exit.

  501. Defaults to <samp>false</samp>. This option is deprecated, please use the

  502. <code>-sources</code> option of ffmpeg to list the available input devices.

  503. </p>

  504. </dd>

  505. <dt><span><samp>list_formats</samp></span></dt>

  506. <dd><p>If set to <samp>true</samp>, print a list of supported formats and exit.

  507. Defaults to <samp>false</samp>.

  508. </p>

  509. </dd>

  510. <dt><span><samp>format_code &lt;FourCC&gt;</samp></span></dt>

  511. <dd><p>This sets the input video format to the format given by the FourCC. To see

  512. the supported values of your device(s) use <samp>list_formats</samp>.

  513. Note that there is a FourCC <samp>'pal '</samp> that can also be used

  514. as <samp>pal</samp> (3 letters).

  515. Default behavior is autodetection of the input video format, if the hardware

  516. supports it.

  517. </p>

  518. </dd>

  519. <dt><span><samp>raw_format</samp></span></dt>

  520. <dd><p>Set the pixel format of the captured video.

  521. Available values are:

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

  523. <dt><span>&lsquo;<samp>auto</samp>&rsquo;</span></dt>

  524. <dd>

  525. <p>This is the default which means 8-bit YUV 422 or 8-bit ARGB if format

  526. autodetection is used, 8-bit YUV 422 otherwise.

  527. </p>

  528. </dd>

  529. <dt><span>&lsquo;<samp>uyvy422</samp>&rsquo;</span></dt>

  530. <dd>

  531. <p>8-bit YUV 422.

  532. </p>

  533. </dd>

  534. <dt><span>&lsquo;<samp>yuv422p10</samp>&rsquo;</span></dt>

  535. <dd>

  536. <p>10-bit YUV 422.

  537. </p>

  538. </dd>

  539. <dt><span>&lsquo;<samp>argb</samp>&rsquo;</span></dt>

  540. <dd>

  541. <p>8-bit RGB.

  542. </p>

  543. </dd>

  544. <dt><span>&lsquo;<samp>bgra</samp>&rsquo;</span></dt>

  545. <dd>

  546. <p>8-bit RGB.

  547. </p>

  548. </dd>

  549. <dt><span>&lsquo;<samp>rgb10</samp>&rsquo;</span></dt>

  550. <dd>

  551. <p>10-bit RGB.

  552. </p>

  553. </dd>

  554. </dl>

  555. 

  556. </dd>

  557. <dt><span><samp>teletext_lines</samp></span></dt>

  558. <dd><p>If set to nonzero, an additional teletext stream will be captured from the

  559. vertical ancillary data. Both SD PAL (576i) and HD (1080i or 1080p)

  560. sources are supported. In case of HD sources, OP47 packets are decoded.

  561. </p>

  562. <p>This option is a bitmask of the SD PAL VBI lines captured, specifically lines 6

  563. to 22, and lines 318 to 335. Line 6 is the LSB in the mask. Selected lines

  564. which do not contain teletext information will be ignored. You can use the

  565. special <samp>all</samp> constant to select all possible lines, or

  566. <samp>standard</samp> to skip lines 6, 318 and 319, which are not compatible with

  567. all receivers.

  568. </p>

  569. <p>For SD sources, ffmpeg needs to be compiled with <code>--enable-libzvbi</code>. For

  570. HD sources, on older (pre-4K) DeckLink card models you have to capture in 10

  571. bit mode.

  572. </p>

  573. </dd>

  574. <dt><span><samp>channels</samp></span></dt>

  575. <dd><p>Defines number of audio channels to capture. Must be &lsquo;<samp>2</samp>&rsquo;, &lsquo;<samp>8</samp>&rsquo; or &lsquo;<samp>16</samp>&rsquo;.

  576. Defaults to &lsquo;<samp>2</samp>&rsquo;.

  577. </p>

  578. </dd>

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

  580. <dd><p>Sets the decklink device duplex/profile mode. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>half</samp>&rsquo;, &lsquo;<samp>full</samp>&rsquo;,

  581. &lsquo;<samp>one_sub_device_full</samp>&rsquo;, &lsquo;<samp>one_sub_device_half</samp>&rsquo;, &lsquo;<samp>two_sub_device_full</samp>&rsquo;,

  582. &lsquo;<samp>four_sub_device_half</samp>&rsquo;

  583. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  584. </p>

  585. <p>Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property.

  586. For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2

  587. sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profile

  588. is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles.

  589. </p>

  590. <p>Valid profile modes for DeckLink 8K Pro(with DeckLink SDK &gt;= 11.0):

  591. &lsquo;<samp>one_sub_device_full</samp>&rsquo;, &lsquo;<samp>one_sub_device_half</samp>&rsquo;, &lsquo;<samp>two_sub_device_full</samp>&rsquo;,

  592. &lsquo;<samp>four_sub_device_half</samp>&rsquo;

  593. </p>

  594. <p>Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2:

  595. &lsquo;<samp>half</samp>&rsquo;, &lsquo;<samp>full</samp>&rsquo;

  596. </p>

  597. </dd>

  598. <dt><span><samp>timecode_format</samp></span></dt>

  599. <dd><p>Timecode type to include in the frame and video stream metadata. Must be

  600. &lsquo;<samp>none</samp>&rsquo;, &lsquo;<samp>rp188vitc</samp>&rsquo;, &lsquo;<samp>rp188vitc2</samp>&rsquo;, &lsquo;<samp>rp188ltc</samp>&rsquo;,

  601. &lsquo;<samp>rp188hfr</samp>&rsquo;, &lsquo;<samp>rp188any</samp>&rsquo;, &lsquo;<samp>vitc</samp>&rsquo;, &lsquo;<samp>vitc2</samp>&rsquo;, or &lsquo;<samp>serial</samp>&rsquo;.

  602. Defaults to &lsquo;<samp>none</samp>&rsquo; (not included).

  603. </p>

  604. <p>In order to properly support 50/60 fps timecodes, the ordering of the queried

  605. timecode types for &lsquo;<samp>rp188any</samp>&rsquo; is HFR, VITC1, VITC2 and LTC for &gt;30 fps

  606. content. Note that this is slightly different to the ordering used by the

  607. DeckLink API, which is HFR, VITC1, LTC, VITC2.

  608. </p>

  609. </dd>

  610. <dt><span><samp>video_input</samp></span></dt>

  611. <dd><p>Sets the video input source. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>sdi</samp>&rsquo;, &lsquo;<samp>hdmi</samp>&rsquo;,

  612. &lsquo;<samp>optical_sdi</samp>&rsquo;, &lsquo;<samp>component</samp>&rsquo;, &lsquo;<samp>composite</samp>&rsquo; or &lsquo;<samp>s_video</samp>&rsquo;.

  613. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  614. </p>

  615. </dd>

  616. <dt><span><samp>audio_input</samp></span></dt>

  617. <dd><p>Sets the audio input source. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>embedded</samp>&rsquo;,

  618. &lsquo;<samp>aes_ebu</samp>&rsquo;, &lsquo;<samp>analog</samp>&rsquo;, &lsquo;<samp>analog_xlr</samp>&rsquo;, &lsquo;<samp>analog_rca</samp>&rsquo; or

  619. &lsquo;<samp>microphone</samp>&rsquo;. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  620. </p>

  621. </dd>

  622. <dt><span><samp>video_pts</samp></span></dt>

  623. <dd><p>Sets the video packet timestamp source. Must be &lsquo;<samp>video</samp>&rsquo;, &lsquo;<samp>audio</samp>&rsquo;,

  624. &lsquo;<samp>reference</samp>&rsquo;, &lsquo;<samp>wallclock</samp>&rsquo; or &lsquo;<samp>abs_wallclock</samp>&rsquo;.

  625. Defaults to &lsquo;<samp>video</samp>&rsquo;.

  626. </p>

  627. </dd>

  628. <dt><span><samp>audio_pts</samp></span></dt>

  629. <dd><p>Sets the audio packet timestamp source. Must be &lsquo;<samp>video</samp>&rsquo;, &lsquo;<samp>audio</samp>&rsquo;,

  630. &lsquo;<samp>reference</samp>&rsquo;, &lsquo;<samp>wallclock</samp>&rsquo; or &lsquo;<samp>abs_wallclock</samp>&rsquo;.

  631. Defaults to &lsquo;<samp>audio</samp>&rsquo;.

  632. </p>

  633. </dd>

  634. <dt><span><samp>draw_bars</samp></span></dt>

  635. <dd><p>If set to &lsquo;<samp>true</samp>&rsquo;, color bars are drawn in the event of a signal loss.

  636. Defaults to &lsquo;<samp>true</samp>&rsquo;.

  637. </p>

  638. </dd>

  639. <dt><span><samp>queue_size</samp></span></dt>

  640. <dd><p>Sets maximum input buffer size in bytes. If the buffering reaches this value,

  641. incoming frames will be dropped.

  642. Defaults to &lsquo;<samp>1073741824</samp>&rsquo;.

  643. </p>

  644. </dd>

  645. <dt><span><samp>audio_depth</samp></span></dt>

  646. <dd><p>Sets the audio sample bit depth. Must be &lsquo;<samp>16</samp>&rsquo; or &lsquo;<samp>32</samp>&rsquo;.

  647. Defaults to &lsquo;<samp>16</samp>&rsquo;.

  648. </p>

  649. </dd>

  650. <dt><span><samp>decklink_copyts</samp></span></dt>

  651. <dd><p>If set to <samp>true</samp>, timestamps are forwarded as they are without removing

  652. the initial offset.

  653. Defaults to <samp>false</samp>.

  654. </p>

  655. </dd>

  656. <dt><span><samp>timestamp_align</samp></span></dt>

  657. <dd><p>Capture start time alignment in seconds. If set to nonzero, input frames are

  658. dropped till the system timestamp aligns with configured value.

  659. Alignment difference of up to one frame duration is tolerated.

  660. This is useful for maintaining input synchronization across N different

  661. hardware devices deployed for &rsquo;N-way&rsquo; redundancy. The system time of different

  662. hardware devices should be synchronized with protocols such as NTP or PTP,

  663. before using this option.

  664. Note that this method is not foolproof. In some border cases input

  665. synchronization may not happen due to thread scheduling jitters in the OS.

  666. Either sync could go wrong by 1 frame or in a rarer case

  667. <samp>timestamp_align</samp> seconds.

  668. Defaults to &lsquo;<samp>0</samp>&rsquo;.

  669. </p>

  670. </dd>

  671. <dt><span><samp>wait_for_tc (<em>bool</em>)</samp></span></dt>

  672. <dd><p>Drop frames till a frame with timecode is received. Sometimes serial timecode

  673. isn&rsquo;t received with the first input frame. If that happens, the stored stream

  674. timecode will be inaccurate. If this option is set to <samp>true</samp>, input frames

  675. are dropped till a frame with timecode is received.

  676. Option <var>timecode_format</var> must be specified.

  677. Defaults to <samp>false</samp>.

  678. </p>

  679. </dd>

  680. <dt><span><samp>enable_klv(<em>bool</em>)</samp></span></dt>

  681. <dd><p>If set to <samp>true</samp>, extracts KLV data from VANC and outputs KLV packets.

  682. KLV VANC packets are joined based on MID and PSC fields and aggregated into

  683. one KLV packet.

  684. Defaults to <samp>false</samp>.

  685. </p>

  686. </dd>

  687. </dl>

  688. 

  689. <a name="Examples-1"></a>

  690. <h4 class="subsection">3.5.2 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></h4>

  691. 

  692. <ul>

  693. <li> List input devices:

  694. <div class="example">

  695. <pre class="example">ffmpeg -sources decklink

  696. </pre></div>

  697. 

  698. </li><li> List supported formats:

  699. <div class="example">

  700. <pre class="example">ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'

  701. </pre></div>

  702. 

  703. </li><li> Capture video clip at 1080i50:

  704. <div class="example">

  705. <pre class="example">ffmpeg -format_code Hi50 -f decklink -i 'Intensity Pro' -c:a copy -c:v copy output.avi

  706. </pre></div>

  707. 

  708. </li><li> Capture video clip at 1080i50 10 bit:

  709. <div class="example">

  710. <pre class="example">ffmpeg -raw_format yuv422p10 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

  711. </pre></div>

  712. 

  713. </li><li> Capture video clip at 1080i50 with 16 audio channels:

  714. <div class="example">

  715. <pre class="example">ffmpeg -channels 16 -format_code Hi50 -f decklink -i 'UltraStudio Mini Recorder' -c:a copy -c:v copy output.avi

  716. </pre></div>

  717. 

  718. </li></ul>

  719. 

  720. <a name="dshow"></a>

  721. <h3 class="section">3.6 dshow<span class="pull-right"><a class="anchor hidden-xs" href="#dshow" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-dshow" aria-hidden="true">TOC</a></span></h3>

  722. 

  723. <p>Windows DirectShow input device.

  724. </p>

  725. <p>DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.

  726. Currently only audio and video devices are supported.

  727. </p>

  728. <p>Multiple devices may be opened as separate inputs, but they may also be

  729. opened on the same input, which should improve synchronism between them.

  730. </p>

  731. <p>The input name should be in the format:

  732. </p>

  733. <div class="example">

  734. <pre class="example"><var>TYPE</var>=<var>NAME</var>[:<var>TYPE</var>=<var>NAME</var>]

  735. </pre></div>

  736. 

  737. <p>where <var>TYPE</var> can be either <var>audio</var> or <var>video</var>,

  738. and <var>NAME</var> is the device&rsquo;s name or alternative name..

  739. </p>

  740. <a name="Options-5"></a>

  741. <h4 class="subsection">3.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-5" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-5" aria-hidden="true">TOC</a></span></h4>

  742. 

  743. <p>If no options are specified, the device&rsquo;s defaults are used.

  744. If the device does not support the requested options, it will

  745. fail to open.

  746. </p>

  747. <dl compact="compact">

  748. <dt><span><samp>video_size</samp></span></dt>

  749. <dd><p>Set the video size in the captured video.

  750. </p>

  751. </dd>

  752. <dt><span><samp>framerate</samp></span></dt>

  753. <dd><p>Set the frame rate in the captured video.

  754. </p>

  755. </dd>

  756. <dt><span><samp>sample_rate</samp></span></dt>

  757. <dd><p>Set the sample rate (in Hz) of the captured audio.

  758. </p>

  759. </dd>

  760. <dt><span><samp>sample_size</samp></span></dt>

  761. <dd><p>Set the sample size (in bits) of the captured audio.

  762. </p>

  763. </dd>

  764. <dt><span><samp>channels</samp></span></dt>

  765. <dd><p>Set the number of channels in the captured audio.

  766. </p>

  767. </dd>

  768. <dt><span><samp>list_devices</samp></span></dt>

  769. <dd><p>If set to <samp>true</samp>, print a list of devices and exit.

  770. </p>

  771. </dd>

  772. <dt><span><samp>list_options</samp></span></dt>

  773. <dd><p>If set to <samp>true</samp>, print a list of selected device&rsquo;s options

  774. and exit.

  775. </p>

  776. </dd>

  777. <dt><span><samp>video_device_number</samp></span></dt>

  778. <dd><p>Set video device number for devices with the same name (starts at 0,

  779. defaults to 0).

  780. </p>

  781. </dd>

  782. <dt><span><samp>audio_device_number</samp></span></dt>

  783. <dd><p>Set audio device number for devices with the same name (starts at 0,

  784. defaults to 0).

  785. </p>

  786. </dd>

  787. <dt><span><samp>pixel_format</samp></span></dt>

  788. <dd><p>Select pixel format to be used by DirectShow. This may only be set when

  789. the video codec is not set or set to rawvideo.

  790. </p>

  791. </dd>

  792. <dt><span><samp>audio_buffer_size</samp></span></dt>

  793. <dd><p>Set audio device buffer size in milliseconds (which can directly

  794. impact latency, depending on the device).

  795. Defaults to using the audio device&rsquo;s

  796. default buffer size (typically some multiple of 500ms).

  797. Setting this value too low can degrade performance.

  798. See also

  799. <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx">http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx</a>

  800. </p>

  801. </dd>

  802. <dt><span><samp>video_pin_name</samp></span></dt>

  803. <dd><p>Select video capture pin to use by name or alternative name.

  804. </p>

  805. </dd>

  806. <dt><span><samp>audio_pin_name</samp></span></dt>

  807. <dd><p>Select audio capture pin to use by name or alternative name.

  808. </p>

  809. </dd>

  810. <dt><span><samp>crossbar_video_input_pin_number</samp></span></dt>

  811. <dd><p>Select video input pin number for crossbar device. This will be

  812. routed to the crossbar device&rsquo;s Video Decoder output pin.

  813. Note that changing this value can affect future invocations

  814. (sets a new default) until system reboot occurs.

  815. </p>

  816. </dd>

  817. <dt><span><samp>crossbar_audio_input_pin_number</samp></span></dt>

  818. <dd><p>Select audio input pin number for crossbar device. This will be

  819. routed to the crossbar device&rsquo;s Audio Decoder output pin.

  820. Note that changing this value can affect future invocations

  821. (sets a new default) until system reboot occurs.

  822. </p>

  823. </dd>

  824. <dt><span><samp>show_video_device_dialog</samp></span></dt>

  825. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display dialog

  826. to the end user, allowing them to change video filter properties

  827. and configurations manually.

  828. Note that for crossbar devices, adjusting values in this dialog

  829. may be needed at times to toggle between PAL (25 fps) and NTSC (29.97)

  830. input frame rates, sizes, interlacing, etc.  Changing these values can

  831. enable different scan rates/frame rates and avoiding green bars at

  832. the bottom, flickering scan lines, etc.

  833. Note that with some devices, changing these properties can also affect future

  834. invocations (sets new defaults) until system reboot occurs.

  835. </p>

  836. </dd>

  837. <dt><span><samp>show_audio_device_dialog</samp></span></dt>

  838. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display dialog

  839. to the end user, allowing them to change audio filter properties

  840. and configurations manually.

  841. </p>

  842. </dd>

  843. <dt><span><samp>show_video_crossbar_connection_dialog</samp></span></dt>

  844. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display

  845. dialog to the end user, allowing them to manually

  846. modify crossbar pin routings, when it opens a video device.

  847. </p>

  848. </dd>

  849. <dt><span><samp>show_audio_crossbar_connection_dialog</samp></span></dt>

  850. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display

  851. dialog to the end user, allowing them to manually

  852. modify crossbar pin routings, when it opens an audio device.

  853. </p>

  854. </dd>

  855. <dt><span><samp>show_analog_tv_tuner_dialog</samp></span></dt>

  856. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display

  857. dialog to the end user, allowing them to manually

  858. modify TV channels and frequencies.

  859. </p>

  860. </dd>

  861. <dt><span><samp>show_analog_tv_tuner_audio_dialog</samp></span></dt>

  862. <dd><p>If set to <samp>true</samp>, before capture starts, popup a display

  863. dialog to the end user, allowing them to manually

  864. modify TV audio (like mono vs. stereo, Language A,B or C).

  865. </p>

  866. </dd>

  867. <dt><span><samp>audio_device_load</samp></span></dt>

  868. <dd><p>Load an audio capture filter device from file instead of searching

  869. it by name. It may load additional parameters too, if the filter

  870. supports the serialization of its properties to.

  871. To use this an audio capture source has to be specified, but it can

  872. be anything even fake one.

  873. </p>

  874. </dd>

  875. <dt><span><samp>audio_device_save</samp></span></dt>

  876. <dd><p>Save the currently used audio capture filter device and its

  877. parameters (if the filter supports it) to a file.

  878. If a file with the same name exists it will be overwritten.

  879. </p>

  880. </dd>

  881. <dt><span><samp>video_device_load</samp></span></dt>

  882. <dd><p>Load a video capture filter device from file instead of searching

  883. it by name. It may load additional parameters too, if the filter

  884. supports the serialization of its properties to.

  885. To use this a video capture source has to be specified, but it can

  886. be anything even fake one.

  887. </p>

  888. </dd>

  889. <dt><span><samp>video_device_save</samp></span></dt>

  890. <dd><p>Save the currently used video capture filter device and its

  891. parameters (if the filter supports it) to a file.

  892. If a file with the same name exists it will be overwritten.

  893. </p>

  894. </dd>

  895. <dt><span><samp>use_video_device_timestamps</samp></span></dt>

  896. <dd><p>If set to <samp>false</samp>, the timestamp for video frames will be

  897. derived from the wallclock instead of the timestamp provided by

  898. the capture device. This allows working around devices that

  899. provide unreliable timestamps.

  900. </p>

  901. </dd>

  902. </dl>

  903. 

  904. <a name="Examples-2"></a>

  905. <h4 class="subsection">3.6.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-2" aria-hidden="true">TOC</a></span></h4>

  906. 

  907. <ul>

  908. <li> Print the list of DirectShow supported devices and exit:

  909. <div class="example">

  910. <pre class="example">$ ffmpeg -list_devices true -f dshow -i dummy

  911. </pre></div>

  912. 

  913. </li><li> Open video device <var>Camera</var>:

  914. <div class="example">

  915. <pre class="example">$ ffmpeg -f dshow -i video=&quot;Camera&quot;

  916. </pre></div>

  917. 

  918. </li><li> Open second video device with name <var>Camera</var>:

  919. <div class="example">

  920. <pre class="example">$ ffmpeg -f dshow -video_device_number 1 -i video=&quot;Camera&quot;

  921. </pre></div>

  922. 

  923. </li><li> Open video device <var>Camera</var> and audio device <var>Microphone</var>:

  924. <div class="example">

  925. <pre class="example">$ ffmpeg -f dshow -i video=&quot;Camera&quot;:audio=&quot;Microphone&quot;

  926. </pre></div>

  927. 

  928. </li><li> Print the list of supported options in selected device and exit:

  929. <div class="example">

  930. <pre class="example">$ ffmpeg -list_options true -f dshow -i video=&quot;Camera&quot;

  931. </pre></div>

  932. 

  933. </li><li> Specify pin names to capture by name or alternative name, specify alternative device name:

  934. <div class="example">

  935. <pre class="example">$ ffmpeg -f dshow -audio_pin_name &quot;Audio Out&quot; -video_pin_name 2 -i video=video=&quot;@device_pnp_\\?\pci#ven_1a0a&amp;dev_6200&amp;subsys_62021461&amp;rev_01#4&amp;e2c7dd6&amp;0&amp;00e1#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\{ca465100-deb0-4d59-818f-8c477184adf6}&quot;:audio=&quot;Microphone&quot;

  936. </pre></div>

  937. 

  938. </li><li> Configure a crossbar device, specifying crossbar pins, allow user to adjust video capture properties at startup:

  939. <div class="example">

  940. <pre class="example">$ ffmpeg -f dshow -show_video_device_dialog true -crossbar_video_input_pin_number 0

  941.      -crossbar_audio_input_pin_number 3 -i video=&quot;AVerMedia BDA Analog Capture&quot;:audio=&quot;AVerMedia BDA Analog Capture&quot;

  942. </pre></div>

  943. 

  944. </li></ul>

  945. 

  946. <a name="fbdev"></a>

  947. <h3 class="section">3.7 fbdev<span class="pull-right"><a class="anchor hidden-xs" href="#fbdev" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-fbdev" aria-hidden="true">TOC</a></span></h3>

  948. 

  949. <p>Linux framebuffer input device.

  950. </p>

  951. <p>The Linux framebuffer is a graphic hardware-independent abstraction

  952. layer to show graphics on a computer monitor, typically on the

  953. console. It is accessed through a file device node, usually

  954. <samp>/dev/fb0</samp>.

  955. </p>

  956. <p>For more detailed information read the file

  957. Documentation/fb/framebuffer.txt included in the Linux source tree.

  958. </p>

  959. <p>See also <a href="http://linux-fbdev.sourceforge.net/">http://linux-fbdev.sourceforge.net/</a>, and fbset(1).

  960. </p>

  961. <p>To record from the framebuffer device <samp>/dev/fb0</samp> with

  962. <code>ffmpeg</code>:

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

  964. <pre class="example">ffmpeg -f fbdev -framerate 10 -i /dev/fb0 out.avi

  965. </pre></div>

  966. 

  967. <p>You can take a single screenshot image with the command:

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

  969. <pre class="example">ffmpeg -f fbdev -framerate 1 -i /dev/fb0 -frames:v 1 screenshot.jpeg

  970. </pre></div>

  971. 

  972. <a name="Options-6"></a>

  973. <h4 class="subsection">3.7.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-6" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-6" aria-hidden="true">TOC</a></span></h4>

  974. 

  975. <dl compact="compact">

  976. <dt><span><samp>framerate</samp></span></dt>

  977. <dd><p>Set the frame rate. Default is 25.

  978. </p>

  979. </dd>

  980. </dl>

  981. 

  982. <a name="gdigrab"></a>

  983. <h3 class="section">3.8 gdigrab<span class="pull-right"><a class="anchor hidden-xs" href="#gdigrab" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-gdigrab" aria-hidden="true">TOC</a></span></h3>

  984. 

  985. <p>Win32 GDI-based screen capture device.

  986. </p>

  987. <p>This device allows you to capture a region of the display on Windows.

  988. </p>

  989. <p>There are two options for the input filename:

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

  991. <pre class="example">desktop

  992. </pre></div>

  993. <p>or

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

  995. <pre class="example">title=<var>window_title</var>

  996. </pre></div>

  997. 

  998. <p>The first option will capture the entire desktop, or a fixed region of the

  999. desktop. The second option will instead capture the contents of a single

  1000. window, regardless of its position on the screen.

  1001. </p>

  1002. <p>For example, to grab the entire desktop using <code>ffmpeg</code>:

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

  1004. <pre class="example">ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg

  1005. </pre></div>

  1006. 

  1007. <p>Grab a 640x480 region at position <code>10,20</code>:

  1008. </p><div class="example">

  1009. <pre class="example">ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg

  1010. </pre></div>

  1011. 

  1012. <p>Grab the contents of the window named &quot;Calculator&quot;

  1013. </p><div class="example">

  1014. <pre class="example">ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg

  1015. </pre></div>

  1016. 

  1017. <a name="Options-7"></a>

  1018. <h4 class="subsection">3.8.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-7" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-7" aria-hidden="true">TOC</a></span></h4>

  1019. 

  1020. <dl compact="compact">

  1021. <dt><span><samp>draw_mouse</samp></span></dt>

  1022. <dd><p>Specify whether to draw the mouse pointer. Use the value <code>0</code> to

  1023. not draw the pointer. Default value is <code>1</code>.

  1024. </p>

  1025. </dd>

  1026. <dt><span><samp>framerate</samp></span></dt>

  1027. <dd><p>Set the grabbing frame rate. Default value is <code>ntsc</code>,

  1028. corresponding to a frame rate of <code>30000/1001</code>.

  1029. </p>

  1030. </dd>

  1031. <dt><span><samp>show_region</samp></span></dt>

  1032. <dd><p>Show grabbed region on screen.

  1033. </p>

  1034. <p>If <var>show_region</var> is specified with <code>1</code>, then the grabbing

  1035. region will be indicated on screen. With this option, it is easy to

  1036. know what is being grabbed if only a portion of the screen is grabbed.

  1037. </p>

  1038. <p>Note that <var>show_region</var> is incompatible with grabbing the contents

  1039. of a single window.

  1040. </p>

  1041. <p>For example:

  1042. </p><div class="example">

  1043. <pre class="example">ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg

  1044. </pre></div>

  1045. 

  1046. </dd>

  1047. <dt><span><samp>video_size</samp></span></dt>

  1048. <dd><p>Set the video frame size. The default is to capture the full screen if <samp>desktop</samp> is selected, or the full window size if <samp>title=<var>window_title</var></samp> is selected.

  1049. </p>

  1050. </dd>

  1051. <dt><span><samp>offset_x</samp></span></dt>

  1052. <dd><p>When capturing a region with <var>video_size</var>, set the distance from the left edge of the screen or desktop.

  1053. </p>

  1054. <p>Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative <var>offset_x</var> value to move the region to that monitor.

  1055. </p>

  1056. </dd>

  1057. <dt><span><samp>offset_y</samp></span></dt>

  1058. <dd><p>When capturing a region with <var>video_size</var>, set the distance from the top edge of the screen or desktop.

  1059. </p>

  1060. <p>Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative <var>offset_y</var> value to move the region to that monitor.

  1061. </p>

  1062. </dd>

  1063. </dl>

  1064. 

  1065. <a name="iec61883"></a>

  1066. <h3 class="section">3.9 iec61883<span class="pull-right"><a class="anchor hidden-xs" href="#iec61883" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-iec61883" aria-hidden="true">TOC</a></span></h3>

  1067. 

  1068. <p>FireWire DV/HDV input device using libiec61883.

  1069. </p>

  1070. <p>To enable this input device, you need libiec61883, libraw1394 and

  1071. libavc1394 installed on your system. Use the configure option

  1072. <code>--enable-libiec61883</code> to compile with the device enabled.

  1073. </p>

  1074. <p>The iec61883 capture device supports capturing from a video device

  1075. connected via IEEE1394 (FireWire), using libiec61883 and the new Linux

  1076. FireWire stack (juju). This is the default DV/HDV input method in Linux

  1077. Kernel 2.6.37 and later, since the old FireWire stack was removed.

  1078. </p>

  1079. <p>Specify the FireWire port to be used as input file, or &quot;auto&quot;

  1080. to choose the first port connected.

  1081. </p>

  1082. <a name="Options-8"></a>

  1083. <h4 class="subsection">3.9.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-8" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-8" aria-hidden="true">TOC</a></span></h4>

  1084. 

  1085. <dl compact="compact">

  1086. <dt><span><samp>dvtype</samp></span></dt>

  1087. <dd><p>Override autodetection of DV/HDV. This should only be used if auto

  1088. detection does not work, or if usage of a different device type

  1089. should be prohibited. Treating a DV device as HDV (or vice versa) will

  1090. not work and result in undefined behavior.

  1091. The values <samp>auto</samp>, <samp>dv</samp> and <samp>hdv</samp> are supported.

  1092. </p>

  1093. </dd>

  1094. <dt><span><samp>dvbuffer</samp></span></dt>

  1095. <dd><p>Set maximum size of buffer for incoming data, in frames. For DV, this

  1096. is an exact value. For HDV, it is not frame exact, since HDV does

  1097. not have a fixed frame size.

  1098. </p>

  1099. </dd>

  1100. <dt><span><samp>dvguid</samp></span></dt>

  1101. <dd><p>Select the capture device by specifying its GUID. Capturing will only

  1102. be performed from the specified device and fails if no device with the

  1103. given GUID is found. This is useful to select the input if multiple

  1104. devices are connected at the same time.

  1105. Look at /sys/bus/firewire/devices to find out the GUIDs.

  1106. </p>

  1107. </dd>

  1108. </dl>

  1109. 

  1110. <a name="Examples-3"></a>

  1111. <h4 class="subsection">3.9.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-3" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-3" aria-hidden="true">TOC</a></span></h4>

  1112. 

  1113. <ul>

  1114. <li> Grab and show the input of a FireWire DV/HDV device.

  1115. <div class="example">

  1116. <pre class="example">ffplay -f iec61883 -i auto

  1117. </pre></div>

  1118. 

  1119. </li><li> Grab and record the input of a FireWire DV/HDV device,

  1120. using a packet buffer of 100000 packets if the source is HDV.

  1121. <div class="example">

  1122. <pre class="example">ffmpeg -f iec61883 -i auto -dvbuffer 100000 out.mpg

  1123. </pre></div>

  1124. 

  1125. </li></ul>

  1126. 

  1127. <a name="jack"></a>

  1128. <h3 class="section">3.10 jack<span class="pull-right"><a class="anchor hidden-xs" href="#jack" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-jack" aria-hidden="true">TOC</a></span></h3>

  1129. 

  1130. <p>JACK input device.

  1131. </p>

  1132. <p>To enable this input device during configuration you need libjack

  1133. installed on your system.

  1134. </p>

  1135. <p>A JACK input device creates one or more JACK writable clients, one for

  1136. each audio channel, with name <var>client_name</var>:input_<var>N</var>, where

  1137. <var>client_name</var> is the name provided by the application, and <var>N</var>

  1138. is a number which identifies the channel.

  1139. Each writable client will send the acquired data to the FFmpeg input

  1140. device.

  1141. </p>

  1142. <p>Once you have created one or more JACK readable clients, you need to

  1143. connect them to one or more JACK writable clients.

  1144. </p>

  1145. <p>To connect or disconnect JACK clients you can use the <code>jack_connect</code>

  1146. and <code>jack_disconnect</code> programs, or do it through a graphical interface,

  1147. for example with <code>qjackctl</code>.

  1148. </p>

  1149. <p>To list the JACK clients and their properties you can invoke the command

  1150. <code>jack_lsp</code>.

  1151. </p>

  1152. <p>Follows an example which shows how to capture a JACK readable client

  1153. with <code>ffmpeg</code>.

  1154. </p><div class="example">

  1155. <pre class="example"># Create a JACK writable client with name &quot;ffmpeg&quot;.

  1156. $ ffmpeg -f jack -i ffmpeg -y out.wav

  1157. 

  1158. # Start the sample jack_metro readable client.

  1159. $ jack_metro -b 120 -d 0.2 -f 4000

  1160. 

  1161. # List the current JACK clients.

  1162. $ jack_lsp -c

  1163. system:capture_1

  1164. system:capture_2

  1165. system:playback_1

  1166. system:playback_2

  1167. ffmpeg:input_1

  1168. metro:120_bpm

  1169. 

  1170. # Connect metro to the ffmpeg writable client.

  1171. $ jack_connect metro:120_bpm ffmpeg:input_1

  1172. </pre></div>

  1173. 

  1174. <p>For more information read:

  1175. <a href="http://jackaudio.org/">http://jackaudio.org/</a>

  1176. </p>

  1177. <a name="Options-9"></a>

  1178. <h4 class="subsection">3.10.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-9" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-9" aria-hidden="true">TOC</a></span></h4>

  1179. 

  1180. <dl compact="compact">

  1181. <dt><span><samp>channels</samp></span></dt>

  1182. <dd><p>Set the number of channels. Default is 2.

  1183. </p>

  1184. </dd>

  1185. </dl>

  1186. 

  1187. <a name="kmsgrab"></a>

  1188. <h3 class="section">3.11 kmsgrab<span class="pull-right"><a class="anchor hidden-xs" href="#kmsgrab" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-kmsgrab" aria-hidden="true">TOC</a></span></h3>

  1189. 

  1190. <p>KMS video input device.

  1191. </p>

  1192. <p>Captures the KMS scanout framebuffer associated with a specified CRTC or plane as a

  1193. DRM object that can be passed to other hardware functions.

  1194. </p>

  1195. <p>Requires either DRM master or CAP_SYS_ADMIN to run.

  1196. </p>

  1197. <p>If you don&rsquo;t understand what all of that means, you probably don&rsquo;t want this.  Look at

  1198. <samp>x11grab</samp> instead.

  1199. </p>

  1200. <a name="Options-10"></a>

  1201. <h4 class="subsection">3.11.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-10" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-10" aria-hidden="true">TOC</a></span></h4>

  1202. 

  1203. <dl compact="compact">

  1204. <dt><span><samp>device</samp></span></dt>

  1205. <dd><p>DRM device to capture on.  Defaults to <samp>/dev/dri/card0</samp>.

  1206. </p>

  1207. </dd>

  1208. <dt><span><samp>format</samp></span></dt>

  1209. <dd><p>Pixel format of the framebuffer.  This can be autodetected if you are running Linux 5.7

  1210. or later, but needs to be provided for earlier versions.  Defaults to <samp>bgr0</samp>,

  1211. which is the most common format used by the Linux console and Xorg X server.

  1212. </p>

  1213. </dd>

  1214. <dt><span><samp>format_modifier</samp></span></dt>

  1215. <dd><p>Format modifier to signal on output frames.  This is necessary to import correctly into

  1216. some APIs.  It can be autodetected if you are running Linux 5.7 or later, but will need

  1217. to be provided explicitly when needed in earlier versions.  See the libdrm documentation

  1218. for possible values.

  1219. </p>

  1220. </dd>

  1221. <dt><span><samp>crtc_id</samp></span></dt>

  1222. <dd><p>KMS CRTC ID to define the capture source.  The first active plane on the given CRTC

  1223. will be used.

  1224. </p>

  1225. </dd>

  1226. <dt><span><samp>plane_id</samp></span></dt>

  1227. <dd><p>KMS plane ID to define the capture source.  Defaults to the first active plane found if

  1228. neither <samp>crtc_id</samp> nor <samp>plane_id</samp> are specified.

  1229. </p>

  1230. </dd>

  1231. <dt><span><samp>framerate</samp></span></dt>

  1232. <dd><p>Framerate to capture at.  This is not synchronised to any page flipping or framebuffer

  1233. changes - it just defines the interval at which the framebuffer is sampled.  Sampling

  1234. faster than the framebuffer update rate will generate independent frames with the same

  1235. content.  Defaults to <code>30</code>.

  1236. </p>

  1237. </dd>

  1238. </dl>

  1239. 

  1240. <a name="Examples-4"></a>

  1241. <h4 class="subsection">3.11.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-4" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-4" aria-hidden="true">TOC</a></span></h4>

  1242. 

  1243. <ul>

  1244. <li> Capture from the first active plane, download the result to normal frames and encode.

  1245. This will only work if the framebuffer is both linear and mappable - if not, the result

  1246. may be scrambled or fail to download.

  1247. <div class="example">

  1248. <pre class="example">ffmpeg -f kmsgrab -i - -vf 'hwdownload,format=bgr0' output.mp4

  1249. </pre></div>

  1250. 

  1251. </li><li> Capture from CRTC ID 42 at 60fps, map the result to VAAPI, convert to NV12 and encode as H.264.

  1252. <div class="example">

  1253. <pre class="example">ffmpeg -crtc_id 42 -framerate 60 -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12' -c:v h264_vaapi output.mp4

  1254. </pre></div>

  1255. 

  1256. </li><li> To capture only part of a plane the output can be cropped - this can be used to capture

  1257. a single window, as long as it has a known absolute position and size.  For example, to

  1258. capture and encode the middle quarter of a 1920x1080 plane:

  1259. <div class="example">

  1260. <pre class="example">ffmpeg -f kmsgrab -i - -vf 'hwmap=derive_device=vaapi,crop=960:540:480:270,scale_vaapi=960:540:nv12' -c:v h264_vaapi output.mp4

  1261. </pre></div>

  1262. 

  1263. </li></ul>

  1264. 

  1265. <a name="lavfi"></a>

  1266. <h3 class="section">3.12 lavfi<span class="pull-right"><a class="anchor hidden-xs" href="#lavfi" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-lavfi" aria-hidden="true">TOC</a></span></h3>

  1267. 

  1268. <p>Libavfilter input virtual device.

  1269. </p>

  1270. <p>This input device reads data from the open output pads of a libavfilter

  1271. filtergraph.

  1272. </p>

  1273. <p>For each filtergraph open output, the input device will create a

  1274. corresponding stream which is mapped to the generated output. Currently

  1275. only video data is supported. The filtergraph is specified through the

  1276. option <samp>graph</samp>.

  1277. </p>

  1278. <a name="Options-11"></a>

  1279. <h4 class="subsection">3.12.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-11" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-11" aria-hidden="true">TOC</a></span></h4>

  1280. 

  1281. <dl compact="compact">

  1282. <dt><span><samp>graph</samp></span></dt>

  1283. <dd><p>Specify the filtergraph to use as input. Each video open output must be

  1284. labelled by a unique string of the form &quot;out<var>N</var>&quot;, where <var>N</var> is a

  1285. number starting from 0 corresponding to the mapped input stream

  1286. generated by the device.

  1287. The first unlabelled output is automatically assigned to the &quot;out0&quot;

  1288. label, but all the others need to be specified explicitly.

  1289. </p>

  1290. <p>The suffix &quot;+subcc&quot; can be appended to the output label to create an extra

  1291. stream with the closed captions packets attached to that output

  1292. (experimental; only for EIA-608 / CEA-708 for now).

  1293. The subcc streams are created after all the normal streams, in the order of

  1294. the corresponding stream.

  1295. For example, if there is &quot;out19+subcc&quot;, &quot;out7+subcc&quot; and up to &quot;out42&quot;, the

  1296. stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.

  1297. </p>

  1298. <p>If not specified defaults to the filename specified for the input

  1299. device.

  1300. </p>

  1301. </dd>

  1302. <dt><span><samp>graph_file</samp></span></dt>

  1303. <dd><p>Set the filename of the filtergraph to be read and sent to the other

  1304. filters. Syntax of the filtergraph is the same as the one specified by

  1305. the option <var>graph</var>.

  1306. </p>

  1307. </dd>

  1308. <dt><span><samp>dumpgraph</samp></span></dt>

  1309. <dd><p>Dump graph to stderr.

  1310. </p>

  1311. </dd>

  1312. </dl>

  1313. 

  1314. <a name="Examples-5"></a>

  1315. <h4 class="subsection">3.12.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-5" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-5" aria-hidden="true">TOC</a></span></h4>

  1316. 

  1317. <ul>

  1318. <li> Create a color video stream and play it back with <code>ffplay</code>:

  1319. <div class="example">

  1320. <pre class="example">ffplay -f lavfi -graph &quot;color=c=pink [out0]&quot; dummy

  1321. </pre></div>

  1322. 

  1323. </li><li> As the previous example, but use filename for specifying the graph

  1324. description, and omit the &quot;out0&quot; label:

  1325. <div class="example">

  1326. <pre class="example">ffplay -f lavfi color=c=pink

  1327. </pre></div>

  1328. 

  1329. </li><li> Create three different video test filtered sources and play them:

  1330. <div class="example">

  1331. <pre class="example">ffplay -f lavfi -graph &quot;testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]&quot; test3

  1332. </pre></div>

  1333. 

  1334. </li><li> Read an audio stream from a file using the amovie source and play it

  1335. back with <code>ffplay</code>:

  1336. <div class="example">

  1337. <pre class="example">ffplay -f lavfi &quot;amovie=test.wav&quot;

  1338. </pre></div>

  1339. 

  1340. </li><li> Read an audio stream and a video stream and play it back with

  1341. <code>ffplay</code>:

  1342. <div class="example">

  1343. <pre class="example">ffplay -f lavfi &quot;movie=test.avi[out0];amovie=test.wav[out1]&quot;

  1344. </pre></div>

  1345. 

  1346. </li><li> Dump decoded frames to images and closed captions to a file (experimental):

  1347. <div class="example">

  1348. <pre class="example">ffmpeg -f lavfi -i &quot;movie=test.ts[out0+subcc]&quot; -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin

  1349. </pre></div>

  1350. 

  1351. </li></ul>

  1352. 

  1353. <a name="libcdio"></a>

  1354. <h3 class="section">3.13 libcdio<span class="pull-right"><a class="anchor hidden-xs" href="#libcdio" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libcdio" aria-hidden="true">TOC</a></span></h3>

  1355. 

  1356. <p>Audio-CD input device based on libcdio.

  1357. </p>

  1358. <p>To enable this input device during configuration you need libcdio

  1359. installed on your system. It requires the configure option

  1360. <code>--enable-libcdio</code>.

  1361. </p>

  1362. <p>This device allows playing and grabbing from an Audio-CD.

  1363. </p>

  1364. <p>For example to copy with <code>ffmpeg</code> the entire Audio-CD in <samp>/dev/sr0</samp>,

  1365. you may run the command:

  1366. </p><div class="example">

  1367. <pre class="example">ffmpeg -f libcdio -i /dev/sr0 cd.wav

  1368. </pre></div>

  1369. 

  1370. <a name="Options-12"></a>

  1371. <h4 class="subsection">3.13.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-12" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-12" aria-hidden="true">TOC</a></span></h4>

  1372. <dl compact="compact">

  1373. <dt><span><samp>speed</samp></span></dt>

  1374. <dd><p>Set drive reading speed. Default value is 0.

  1375. </p>

  1376. <p>The speed is specified CD-ROM speed units. The speed is set through

  1377. the libcdio <code>cdio_cddap_speed_set</code> function. On many CD-ROM

  1378. drives, specifying a value too large will result in using the fastest

  1379. speed.

  1380. </p>

  1381. </dd>

  1382. <dt><span><samp>paranoia_mode</samp></span></dt>

  1383. <dd><p>Set paranoia recovery mode flags. It accepts one of the following values:

  1384. </p>

  1385. <dl compact="compact">

  1386. <dt><span>&lsquo;<samp>disable</samp>&rsquo;</span></dt>

  1387. <dt><span>&lsquo;<samp>verify</samp>&rsquo;</span></dt>

  1388. <dt><span>&lsquo;<samp>overlap</samp>&rsquo;</span></dt>

  1389. <dt><span>&lsquo;<samp>neverskip</samp>&rsquo;</span></dt>

  1390. <dt><span>&lsquo;<samp>full</samp>&rsquo;</span></dt>

  1391. </dl>

  1392. 

  1393. <p>Default value is &lsquo;<samp>disable</samp>&rsquo;.

  1394. </p>

  1395. <p>For more information about the available recovery modes, consult the

  1396. paranoia project documentation.

  1397. </p></dd>

  1398. </dl>

  1399. 

  1400. <a name="libdc1394"></a>

  1401. <h3 class="section">3.14 libdc1394<span class="pull-right"><a class="anchor hidden-xs" href="#libdc1394" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-libdc1394" aria-hidden="true">TOC</a></span></h3>

  1402. 

  1403. <p>IIDC1394 input device, based on libdc1394 and libraw1394.

  1404. </p>

  1405. <p>Requires the configure option <code>--enable-libdc1394</code>.

  1406. </p>

  1407. <a name="Options-13"></a>

  1408. <h4 class="subsection">3.14.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-13" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-13" aria-hidden="true">TOC</a></span></h4>

  1409. <dl compact="compact">

  1410. <dt><span><samp>framerate</samp></span></dt>

  1411. <dd><p>Set the frame rate. Default is <code>ntsc</code>, corresponding to a frame

  1412. rate of <code>30000/1001</code>.

  1413. </p>

  1414. </dd>

  1415. <dt><span><samp>pixel_format</samp></span></dt>

  1416. <dd><p>Select the pixel format. Default is <code>uyvy422</code>.

  1417. </p>

  1418. </dd>

  1419. <dt><span><samp>video_size</samp></span></dt>

  1420. <dd><p>Set the video size given as a string such as <code>640x480</code> or <code>hd720</code>.

  1421. Default is <code>qvga</code>.

  1422. </p></dd>

  1423. </dl>

  1424. 

  1425. <a name="openal"></a>

  1426. <h3 class="section">3.15 openal<span class="pull-right"><a class="anchor hidden-xs" href="#openal" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-openal" aria-hidden="true">TOC</a></span></h3>

  1427. 

  1428. <p>The OpenAL input device provides audio capture on all systems with a

  1429. working OpenAL 1.1 implementation.

  1430. </p>

  1431. <p>To enable this input device during configuration, you need OpenAL

  1432. headers and libraries installed on your system, and need to configure

  1433. FFmpeg with <code>--enable-openal</code>.

  1434. </p>

  1435. <p>OpenAL headers and libraries should be provided as part of your OpenAL

  1436. implementation, or as an additional download (an SDK). Depending on your

  1437. installation you may need to specify additional flags via the

  1438. <code>--extra-cflags</code> and <code>--extra-ldflags</code> for allowing the build

  1439. system to locate the OpenAL headers and libraries.

  1440. </p>

  1441. <p>An incomplete list of OpenAL implementations follows:

  1442. </p>

  1443. <dl compact="compact">

  1444. <dt><span><strong>Creative</strong></span></dt>

  1445. <dd><p>The official Windows implementation, providing hardware acceleration

  1446. with supported devices and software fallback.

  1447. See <a href="http://openal.org/">http://openal.org/</a>.

  1448. </p></dd>

  1449. <dt><span><strong>OpenAL Soft</strong></span></dt>

  1450. <dd><p>Portable, open source (LGPL) software implementation. Includes

  1451. backends for the most common sound APIs on the Windows, Linux,

  1452. Solaris, and BSD operating systems.

  1453. See <a href="http://kcat.strangesoft.net/openal.html">http://kcat.strangesoft.net/openal.html</a>.

  1454. </p></dd>

  1455. <dt><span><strong>Apple</strong></span></dt>

  1456. <dd><p>OpenAL is part of Core Audio, the official Mac OS X Audio interface.

  1457. See <a href="http://developer.apple.com/technologies/mac/audio-and-video.html">http://developer.apple.com/technologies/mac/audio-and-video.html</a>

  1458. </p></dd>

  1459. </dl>

  1460. 

  1461. <p>This device allows one to capture from an audio input device handled

  1462. through OpenAL.

  1463. </p>

  1464. <p>You need to specify the name of the device to capture in the provided

  1465. filename. If the empty string is provided, the device will

  1466. automatically select the default device. You can get the list of the

  1467. supported devices by using the option <var>list_devices</var>.

  1468. </p>

  1469. <a name="Options-14"></a>

  1470. <h4 class="subsection">3.15.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-14" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-14" aria-hidden="true">TOC</a></span></h4>

  1471. 

  1472. <dl compact="compact">

  1473. <dt><span><samp>channels</samp></span></dt>

  1474. <dd><p>Set the number of channels in the captured audio. Only the values

  1475. <samp>1</samp> (monaural) and <samp>2</samp> (stereo) are currently supported.

  1476. Defaults to <samp>2</samp>.

  1477. </p>

  1478. </dd>

  1479. <dt><span><samp>sample_size</samp></span></dt>

  1480. <dd><p>Set the sample size (in bits) of the captured audio. Only the values

  1481. <samp>8</samp> and <samp>16</samp> are currently supported. Defaults to

  1482. <samp>16</samp>.

  1483. </p>

  1484. </dd>

  1485. <dt><span><samp>sample_rate</samp></span></dt>

  1486. <dd><p>Set the sample rate (in Hz) of the captured audio.

  1487. Defaults to <samp>44.1k</samp>.

  1488. </p>

  1489. </dd>

  1490. <dt><span><samp>list_devices</samp></span></dt>

  1491. <dd><p>If set to <samp>true</samp>, print a list of devices and exit.

  1492. Defaults to <samp>false</samp>.

  1493. </p>

  1494. </dd>

  1495. </dl>

  1496. 

  1497. <a name="Examples-6"></a>

  1498. <h4 class="subsection">3.15.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-6" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-6" aria-hidden="true">TOC</a></span></h4>

  1499. 

  1500. <p>Print the list of OpenAL supported devices and exit:

  1501. </p><div class="example">

  1502. <pre class="example">$ ffmpeg -list_devices true -f openal -i dummy out.ogg

  1503. </pre></div>

  1504. 

  1505. <p>Capture from the OpenAL device <samp>DR-BT101 via PulseAudio</samp>:

  1506. </p><div class="example">

  1507. <pre class="example">$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg

  1508. </pre></div>

  1509. 

  1510. <p>Capture from the default device (note the empty string &rdquo; as filename):

  1511. </p><div class="example">

  1512. <pre class="example">$ ffmpeg -f openal -i '' out.ogg

  1513. </pre></div>

  1514. 

  1515. <p>Capture from two devices simultaneously, writing to two different files,

  1516. within the same <code>ffmpeg</code> command:

  1517. </p><div class="example">

  1518. <pre class="example">$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg

  1519. </pre></div>

  1520. <p>Note: not all OpenAL implementations support multiple simultaneous capture -

  1521. try the latest OpenAL Soft if the above does not work.

  1522. </p>

  1523. <a name="oss"></a>

  1524. <h3 class="section">3.16 oss<span class="pull-right"><a class="anchor hidden-xs" href="#oss" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-oss" aria-hidden="true">TOC</a></span></h3>

  1525. 

  1526. <p>Open Sound System input device.

  1527. </p>

  1528. <p>The filename to provide to the input device is the device node

  1529. representing the OSS input device, and is usually set to

  1530. <samp>/dev/dsp</samp>.

  1531. </p>

  1532. <p>For example to grab from <samp>/dev/dsp</samp> using <code>ffmpeg</code> use the

  1533. command:

  1534. </p><div class="example">

  1535. <pre class="example">ffmpeg -f oss -i /dev/dsp /tmp/oss.wav

  1536. </pre></div>

  1537. 

  1538. <p>For more information about OSS see:

  1539. <a href="http://manuals.opensound.com/usersguide/dsp.html">http://manuals.opensound.com/usersguide/dsp.html</a>

  1540. </p>

  1541. <a name="Options-15"></a>

  1542. <h4 class="subsection">3.16.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-15" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-15" aria-hidden="true">TOC</a></span></h4>

  1543. 

  1544. <dl compact="compact">

  1545. <dt><span><samp>sample_rate</samp></span></dt>

  1546. <dd><p>Set the sample rate in Hz. Default is 48000.

  1547. </p>

  1548. </dd>

  1549. <dt><span><samp>channels</samp></span></dt>

  1550. <dd><p>Set the number of channels. Default is 2.

  1551. </p>

  1552. </dd>

  1553. </dl>

  1554. 

  1555. <a name="pulse"></a>

  1556. <h3 class="section">3.17 pulse<span class="pull-right"><a class="anchor hidden-xs" href="#pulse" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-pulse" aria-hidden="true">TOC</a></span></h3>

  1557. 

  1558. <p>PulseAudio input device.

  1559. </p>

  1560. <p>To enable this output device you need to configure FFmpeg with <code>--enable-libpulse</code>.

  1561. </p>

  1562. <p>The filename to provide to the input device is a source device or the

  1563. string &quot;default&quot;

  1564. </p>

  1565. <p>To list the PulseAudio source devices and their properties you can invoke

  1566. the command <code>pactl list sources</code>.

  1567. </p>

  1568. <p>More information about PulseAudio can be found on <a href="http://www.pulseaudio.org">http://www.pulseaudio.org</a>.

  1569. </p>

  1570. <a name="Options-16"></a>

  1571. <h4 class="subsection">3.17.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-16" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-16" aria-hidden="true">TOC</a></span></h4>

  1572. <dl compact="compact">

  1573. <dt><span><samp>server</samp></span></dt>

  1574. <dd><p>Connect to a specific PulseAudio server, specified by an IP address.

  1575. Default server is used when not provided.

  1576. </p>

  1577. </dd>

  1578. <dt><span><samp>name</samp></span></dt>

  1579. <dd><p>Specify the application name PulseAudio will use when showing active clients,

  1580. by default it is the <code>LIBAVFORMAT_IDENT</code> string.

  1581. </p>

  1582. </dd>

  1583. <dt><span><samp>stream_name</samp></span></dt>

  1584. <dd><p>Specify the stream name PulseAudio will use when showing active streams,

  1585. by default it is &quot;record&quot;.

  1586. </p>

  1587. </dd>

  1588. <dt><span><samp>sample_rate</samp></span></dt>

  1589. <dd><p>Specify the samplerate in Hz, by default 48kHz is used.

  1590. </p>

  1591. </dd>

  1592. <dt><span><samp>channels</samp></span></dt>

  1593. <dd><p>Specify the channels in use, by default 2 (stereo) is set.

  1594. </p>

  1595. </dd>

  1596. <dt><span><samp>frame_size</samp></span></dt>

  1597. <dd><p>This option does nothing and is deprecated.

  1598. </p>

  1599. </dd>

  1600. <dt><span><samp>fragment_size</samp></span></dt>

  1601. <dd><p>Specify the size in bytes of the minimal buffering fragment in PulseAudio, it

  1602. will affect the audio latency. By default it is set to 50 ms amount of data.

  1603. </p>

  1604. </dd>

  1605. <dt><span><samp>wallclock</samp></span></dt>

  1606. <dd><p>Set the initial PTS using the current time. Default is 1.

  1607. </p>

  1608. </dd>

  1609. </dl>

  1610. 

  1611. <a name="Examples-7"></a>

  1612. <h4 class="subsection">3.17.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-7" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-7" aria-hidden="true">TOC</a></span></h4>

  1613. <p>Record a stream from default device:

  1614. </p><div class="example">

  1615. <pre class="example">ffmpeg -f pulse -i default /tmp/pulse.wav

  1616. </pre></div>

  1617. 

  1618. <a name="sndio"></a>

  1619. <h3 class="section">3.18 sndio<span class="pull-right"><a class="anchor hidden-xs" href="#sndio" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-sndio" aria-hidden="true">TOC</a></span></h3>

  1620. 

  1621. <p>sndio input device.

  1622. </p>

  1623. <p>To enable this input device during configuration you need libsndio

  1624. installed on your system.

  1625. </p>

  1626. <p>The filename to provide to the input device is the device node

  1627. representing the sndio input device, and is usually set to

  1628. <samp>/dev/audio0</samp>.

  1629. </p>

  1630. <p>For example to grab from <samp>/dev/audio0</samp> using <code>ffmpeg</code> use the

  1631. command:

  1632. </p><div class="example">

  1633. <pre class="example">ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav

  1634. </pre></div>

  1635. 

  1636. <a name="Options-17"></a>

  1637. <h4 class="subsection">3.18.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-17" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-17" aria-hidden="true">TOC</a></span></h4>

  1638. 

  1639. <dl compact="compact">

  1640. <dt><span><samp>sample_rate</samp></span></dt>

  1641. <dd><p>Set the sample rate in Hz. Default is 48000.

  1642. </p>

  1643. </dd>

  1644. <dt><span><samp>channels</samp></span></dt>

  1645. <dd><p>Set the number of channels. Default is 2.

  1646. </p>

  1647. </dd>

  1648. </dl>

  1649. 

  1650. <a name="video4linux2_002c-v4l2"></a>

  1651. <h3 class="section">3.19 video4linux2, v4l2<span class="pull-right"><a class="anchor hidden-xs" href="#video4linux2_002c-v4l2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-video4linux2_002c-v4l2" aria-hidden="true">TOC</a></span></h3>

  1652. 

  1653. <p>Video4Linux2 input video device.

  1654. </p>

  1655. <p>&quot;v4l2&quot; can be used as alias for &quot;video4linux2&quot;.

  1656. </p>

  1657. <p>If FFmpeg is built with v4l-utils support (by using the

  1658. <code>--enable-libv4l2</code> configure option), it is possible to use it with the

  1659. <code>-use_libv4l2</code> input device option.

  1660. </p>

  1661. <p>The name of the device to grab is a file device node, usually Linux

  1662. systems tend to automatically create such nodes when the device

  1663. (e.g. an USB webcam) is plugged into the system, and has a name of the

  1664. kind <samp>/dev/video<var>N</var></samp>, where <var>N</var> is a number associated to

  1665. the device.

  1666. </p>

  1667. <p>Video4Linux2 devices usually support a limited set of

  1668. <var>width</var>x<var>height</var> sizes and frame rates. You can check which are

  1669. supported using <code>-list_formats all</code> for Video4Linux2 devices.

  1670. Some devices, like TV cards, support one or more standards. It is possible

  1671. to list all the supported standards using <code>-list_standards all</code>.

  1672. </p>

  1673. <p>The time base for the timestamps is 1 microsecond. Depending on the kernel

  1674. version and configuration, the timestamps may be derived from the real time

  1675. clock (origin at the Unix Epoch) or the monotonic clock (origin usually at

  1676. boot time, unaffected by NTP or manual changes to the clock). The

  1677. <samp>-timestamps abs</samp> or <samp>-ts abs</samp> option can be used to force

  1678. conversion into the real time clock.

  1679. </p>

  1680. <p>Some usage examples of the video4linux2 device with <code>ffmpeg</code>

  1681. and <code>ffplay</code>:

  1682. </p><ul>

  1683. <li> List supported formats for a video4linux2 device:

  1684. <div class="example">

  1685. <pre class="example">ffplay -f video4linux2 -list_formats all /dev/video0

  1686. </pre></div>

  1687. 

  1688. </li><li> Grab and show the input of a video4linux2 device:

  1689. <div class="example">

  1690. <pre class="example">ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0

  1691. </pre></div>

  1692. 

  1693. </li><li> Grab and record the input of a video4linux2 device, leave the

  1694. frame rate and size as previously set:

  1695. <div class="example">

  1696. <pre class="example">ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg

  1697. </pre></div>

  1698. </li></ul>

  1699. 

  1700. <p>For more information about Video4Linux, check <a href="http://linuxtv.org/">http://linuxtv.org/</a>.

  1701. </p>

  1702. <a name="Options-18"></a>

  1703. <h4 class="subsection">3.19.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-18" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-18" aria-hidden="true">TOC</a></span></h4>

  1704. 

  1705. <dl compact="compact">

  1706. <dt><span><samp>standard</samp></span></dt>

  1707. <dd><p>Set the standard. Must be the name of a supported standard. To get a

  1708. list of the supported standards, use the <samp>list_standards</samp>

  1709. option.

  1710. </p>

  1711. </dd>

  1712. <dt><span><samp>channel</samp></span></dt>

  1713. <dd><p>Set the input channel number. Default to -1, which means using the

  1714. previously selected channel.

  1715. </p>

  1716. </dd>

  1717. <dt><span><samp>video_size</samp></span></dt>

  1718. <dd><p>Set the video frame size. The argument must be a string in the form

  1719. <var>WIDTH</var>x<var>HEIGHT</var> or a valid size abbreviation.

  1720. </p>

  1721. </dd>

  1722. <dt><span><samp>pixel_format</samp></span></dt>

  1723. <dd><p>Select the pixel format (only valid for raw video input).

  1724. </p>

  1725. </dd>

  1726. <dt><span><samp>input_format</samp></span></dt>

  1727. <dd><p>Set the preferred pixel format (for raw video) or a codec name.

  1728. This option allows one to select the input format, when several are

  1729. available.

  1730. </p>

  1731. </dd>

  1732. <dt><span><samp>framerate</samp></span></dt>

  1733. <dd><p>Set the preferred video frame rate.

  1734. </p>

  1735. </dd>

  1736. <dt><span><samp>list_formats</samp></span></dt>

  1737. <dd><p>List available formats (supported pixel formats, codecs, and frame

  1738. sizes) and exit.

  1739. </p>

  1740. <p>Available values are:

  1741. </p><dl compact="compact">

  1742. <dt><span>&lsquo;<samp>all</samp>&rsquo;</span></dt>

  1743. <dd><p>Show all available (compressed and non-compressed) formats.

  1744. </p>

  1745. </dd>

  1746. <dt><span>&lsquo;<samp>raw</samp>&rsquo;</span></dt>

  1747. <dd><p>Show only raw video (non-compressed) formats.

  1748. </p>

  1749. </dd>

  1750. <dt><span>&lsquo;<samp>compressed</samp>&rsquo;</span></dt>

  1751. <dd><p>Show only compressed formats.

  1752. </p></dd>

  1753. </dl>

  1754. 

  1755. </dd>

  1756. <dt><span><samp>list_standards</samp></span></dt>

  1757. <dd><p>List supported standards and exit.

  1758. </p>

  1759. <p>Available values are:

  1760. </p><dl compact="compact">

  1761. <dt><span>&lsquo;<samp>all</samp>&rsquo;</span></dt>

  1762. <dd><p>Show all supported standards.

  1763. </p></dd>

  1764. </dl>

  1765. 

  1766. </dd>

  1767. <dt><span><samp>timestamps, ts</samp></span></dt>

  1768. <dd><p>Set type of timestamps for grabbed frames.

  1769. </p>

  1770. <p>Available values are:

  1771. </p><dl compact="compact">

  1772. <dt><span>&lsquo;<samp>default</samp>&rsquo;</span></dt>

  1773. <dd><p>Use timestamps from the kernel.

  1774. </p>

  1775. </dd>

  1776. <dt><span>&lsquo;<samp>abs</samp>&rsquo;</span></dt>

  1777. <dd><p>Use absolute timestamps (wall clock).

  1778. </p>

  1779. </dd>

  1780. <dt><span>&lsquo;<samp>mono2abs</samp>&rsquo;</span></dt>

  1781. <dd><p>Force conversion from monotonic to absolute timestamps.

  1782. </p></dd>

  1783. </dl>

  1784. 

  1785. <p>Default value is <code>default</code>.

  1786. </p>

  1787. </dd>

  1788. <dt><span><samp>use_libv4l2</samp></span></dt>

  1789. <dd><p>Use libv4l2 (v4l-utils) conversion functions. Default is 0.

  1790. </p>

  1791. </dd>

  1792. </dl>

  1793. 

  1794. <a name="vfwcap"></a>

  1795. <h3 class="section">3.20 vfwcap<span class="pull-right"><a class="anchor hidden-xs" href="#vfwcap" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-vfwcap" aria-hidden="true">TOC</a></span></h3>

  1796. 

  1797. <p>VfW (Video for Windows) capture input device.

  1798. </p>

  1799. <p>The filename passed as input is the capture driver number, ranging from

  1800. 0 to 9. You may use &quot;list&quot; as filename to print a list of drivers. Any

  1801. other filename will be interpreted as device number 0.

  1802. </p>

  1803. <a name="Options-19"></a>

  1804. <h4 class="subsection">3.20.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-19" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-19" aria-hidden="true">TOC</a></span></h4>

  1805. 

  1806. <dl compact="compact">

  1807. <dt><span><samp>video_size</samp></span></dt>

  1808. <dd><p>Set the video frame size.

  1809. </p>

  1810. </dd>

  1811. <dt><span><samp>framerate</samp></span></dt>

  1812. <dd><p>Set the grabbing frame rate. Default value is <code>ntsc</code>,

  1813. corresponding to a frame rate of <code>30000/1001</code>.

  1814. </p>

  1815. </dd>

  1816. </dl>

  1817. 

  1818. <a name="x11grab"></a>

  1819. <h3 class="section">3.21 x11grab<span class="pull-right"><a class="anchor hidden-xs" href="#x11grab" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-x11grab" aria-hidden="true">TOC</a></span></h3>

  1820. 

  1821. <p>X11 video input device.

  1822. </p>

  1823. <p>To enable this input device during configuration you need libxcb

  1824. installed on your system. It will be automatically detected during

  1825. configuration.

  1826. </p>

  1827. <p>This device allows one to capture a region of an X11 display.

  1828. </p>

  1829. <p>The filename passed as input has the syntax:

  1830. </p><div class="example">

  1831. <pre class="example">[<var>hostname</var>]:<var>display_number</var>.<var>screen_number</var>[+<var>x_offset</var>,<var>y_offset</var>]

  1832. </pre></div>

  1833. 

  1834. <p><var>hostname</var>:<var>display_number</var>.<var>screen_number</var> specifies the

  1835. X11 display name of the screen to grab from. <var>hostname</var> can be

  1836. omitted, and defaults to &quot;localhost&quot;. The environment variable

  1837. <code>DISPLAY</code> contains the default display name.

  1838. </p>

  1839. <p><var>x_offset</var> and <var>y_offset</var> specify the offsets of the grabbed

  1840. area with respect to the top-left border of the X11 screen. They

  1841. default to 0.

  1842. </p>

  1843. <p>Check the X11 documentation (e.g. <code>man X</code>) for more detailed

  1844. information.

  1845. </p>

  1846. <p>Use the <code>xdpyinfo</code> program for getting basic information about

  1847. the properties of your X11 display (e.g. grep for &quot;name&quot; or

  1848. &quot;dimensions&quot;).

  1849. </p>

  1850. <p>For example to grab from <samp>:0.0</samp> using <code>ffmpeg</code>:

  1851. </p><div class="example">

  1852. <pre class="example">ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg

  1853. </pre></div>

  1854. 

  1855. <p>Grab at position <code>10,20</code>:

  1856. </p><div class="example">

  1857. <pre class="example">ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

  1858. </pre></div>

  1859. 

  1860. <a name="Options-20"></a>

  1861. <h4 class="subsection">3.21.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-20" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-20" aria-hidden="true">TOC</a></span></h4>

  1862. 

  1863. <dl compact="compact">

  1864. <dt><span><samp>select_region</samp></span></dt>

  1865. <dd><p>Specify whether to select the grabbing area graphically using the pointer.

  1866. A value of <code>1</code> prompts the user to select the grabbing area graphically

  1867. by clicking and dragging. A single click with no dragging will select the

  1868. whole screen. A region with zero width or height will also select the whole

  1869. screen. This option overwrites the <var>video_size</var>, <var>grab_x</var>, and

  1870. <var>grab_y</var> options. Default value is <code>0</code>.

  1871. </p>

  1872. </dd>

  1873. <dt><span><samp>draw_mouse</samp></span></dt>

  1874. <dd><p>Specify whether to draw the mouse pointer. A value of <code>0</code> specifies

  1875. not to draw the pointer. Default value is <code>1</code>.

  1876. </p>

  1877. </dd>

  1878. <dt><span><samp>follow_mouse</samp></span></dt>

  1879. <dd><p>Make the grabbed area follow the mouse. The argument can be

  1880. <code>centered</code> or a number of pixels <var>PIXELS</var>.

  1881. </p>

  1882. <p>When it is specified with &quot;centered&quot;, the grabbing region follows the mouse

  1883. pointer and keeps the pointer at the center of region; otherwise, the region

  1884. follows only when the mouse pointer reaches within <var>PIXELS</var> (greater than

  1885. zero) to the edge of region.

  1886. </p>

  1887. <p>For example:

  1888. </p><div class="example">

  1889. <pre class="example">ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg

  1890. </pre></div>

  1891. 

  1892. <p>To follow only when the mouse pointer reaches within 100 pixels to edge:

  1893. </p><div class="example">

  1894. <pre class="example">ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg

  1895. </pre></div>

  1896. 

  1897. </dd>

  1898. <dt><span><samp>framerate</samp></span></dt>

  1899. <dd><p>Set the grabbing frame rate. Default value is <code>ntsc</code>,

  1900. corresponding to a frame rate of <code>30000/1001</code>.

  1901. </p>

  1902. </dd>

  1903. <dt><span><samp>show_region</samp></span></dt>

  1904. <dd><p>Show grabbed region on screen.

  1905. </p>

  1906. <p>If <var>show_region</var> is specified with <code>1</code>, then the grabbing

  1907. region will be indicated on screen. With this option, it is easy to

  1908. know what is being grabbed if only a portion of the screen is grabbed.

  1909. </p>

  1910. </dd>

  1911. <dt><span><samp>region_border</samp></span></dt>

  1912. <dd><p>Set the region border thickness if <samp>-show_region 1</samp> is used.

  1913. Range is 1 to 128 and default is 3 (XCB-based x11grab only).

  1914. </p>

  1915. <p>For example:

  1916. </p><div class="example">

  1917. <pre class="example">ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg

  1918. </pre></div>

  1919. 

  1920. <p>With <var>follow_mouse</var>:

  1921. </p><div class="example">

  1922. <pre class="example">ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg

  1923. </pre></div>

  1924. 

  1925. </dd>

  1926. <dt><span><samp>window_id</samp></span></dt>

  1927. <dd><p>Grab this window, instead of the whole screen. Default value is 0, which maps to

  1928. the whole screen (root window).

  1929. </p>

  1930. <p>The id of a window can be found using the <code>xwininfo</code> program, possibly with options -tree and

  1931. -root.

  1932. </p>

  1933. <p>If the window is later enlarged, the new area is not recorded. Video ends when

  1934. the window is closed, unmapped (i.e., iconified) or shrunk beyond the video

  1935. size (which defaults to the initial window size).

  1936. </p>

  1937. <p>This option disables options <samp>follow_mouse</samp> and <samp>select_region</samp>.

  1938. </p>

  1939. </dd>

  1940. <dt><span><samp>video_size</samp></span></dt>

  1941. <dd><p>Set the video frame size. Default is the full desktop or window.

  1942. </p>

  1943. </dd>

  1944. <dt><span><samp>grab_x</samp></span></dt>

  1945. <dt><span><samp>grab_y</samp></span></dt>

  1946. <dd><p>Set the grabbing region coordinates. They are expressed as offset from

  1947. the top left corner of the X11 window and correspond to the

  1948. <var>x_offset</var> and <var>y_offset</var> parameters in the device name. The

  1949. default value for both options is 0.

  1950. </p></dd>

  1951. </dl>

  1952. 

  1953. <a name="Output-Devices"></a>

  1954. <h2 class="chapter">4 Output Devices<span class="pull-right"><a class="anchor hidden-xs" href="#Output-Devices" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Output-Devices" aria-hidden="true">TOC</a></span></h2>

  1955. 

  1956. <p>Output devices are configured elements in FFmpeg that can write

  1957. multimedia data to an output device attached to your system.

  1958. </p>

  1959. <p>When you configure your FFmpeg build, all the supported output devices

  1960. are enabled by default. You can list all available ones using the

  1961. configure option &quot;&ndash;list-outdevs&quot;.

  1962. </p>

  1963. <p>You can disable all the output devices using the configure option

  1964. &quot;&ndash;disable-outdevs&quot;, and selectively enable an output device using the

  1965. option &quot;&ndash;enable-outdev=<var>OUTDEV</var>&quot;, or you can disable a particular

  1966. input device using the option &quot;&ndash;disable-outdev=<var>OUTDEV</var>&quot;.

  1967. </p>

  1968. <p>The option &quot;-devices&quot; of the ff* tools will display the list of

  1969. enabled output devices.

  1970. </p>

  1971. <p>A description of the currently available output devices follows.

  1972. </p>

  1973. <a name="alsa-1"></a>

  1974. <h3 class="section">4.1 alsa<span class="pull-right"><a class="anchor hidden-xs" href="#alsa-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-alsa-1" aria-hidden="true">TOC</a></span></h3>

  1975. 

  1976. <p>ALSA (Advanced Linux Sound Architecture) output device.

  1977. </p>

  1978. <a name="Examples-8"></a>

  1979. <h4 class="subsection">4.1.1 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-8" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-8" aria-hidden="true">TOC</a></span></h4>

  1980. 

  1981. <ul>

  1982. <li> Play a file on default ALSA device:

  1983. <div class="example">

  1984. <pre class="example">ffmpeg -i INPUT -f alsa default

  1985. </pre></div>

  1986. 

  1987. </li><li> Play a file on soundcard 1, audio device 7:

  1988. <div class="example">

  1989. <pre class="example">ffmpeg -i INPUT -f alsa hw:1,7

  1990. </pre></div>

  1991. </li></ul>

  1992. 

  1993. <a name="AudioToolbox"></a>

  1994. <h3 class="section">4.2 AudioToolbox<span class="pull-right"><a class="anchor hidden-xs" href="#AudioToolbox" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-AudioToolbox" aria-hidden="true">TOC</a></span></h3>

  1995. 

  1996. <p>AudioToolbox output device.

  1997. </p>

  1998. <p>Allows native output to CoreAudio devices on OSX.

  1999. </p>

  2000. <p>The output filename can be empty (or <code>-</code>) to refer to the default system output device or a number that refers to the device index as shown using: <code>-list_devices true</code>.

  2001. </p>

  2002. <p>Alternatively, the audio input device can be chosen by index using the

  2003. <samp>

  2004.     -audio_device_index &lt;INDEX&gt;

  2005. </samp>

  2006. , overriding any device name or index given in the input filename.

  2007. </p>

  2008. <p>All available devices can be enumerated by using <samp>-list_devices true</samp>, listing

  2009. all device names, UIDs and corresponding indices.

  2010. </p>

  2011. <a name="Options-21"></a>

  2012. <h4 class="subsection">4.2.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-21" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-21" aria-hidden="true">TOC</a></span></h4>

  2013. 

  2014. <p>AudioToolbox supports the following options:

  2015. </p>

  2016. <dl compact="compact">

  2017. <dt><span><samp>-audio_device_index &lt;INDEX&gt;</samp></span></dt>

  2018. <dd><p>Specify the audio device by its index. Overrides anything given in the output filename.

  2019. </p>

  2020. </dd>

  2021. </dl>

  2022. 

  2023. <a name="Examples-9"></a>

  2024. <h4 class="subsection">4.2.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-9" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-9" aria-hidden="true">TOC</a></span></h4>

  2025. 

  2026. <ul>

  2027. <li> Print the list of supported devices and output a sine wave to the default device:

  2028. <div class="example">

  2029. <pre class="example">$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -list_devices true -

  2030. </pre></div>

  2031. 

  2032. </li><li> Output a sine wave to the device with the index 2, overriding any output filename:

  2033. <div class="example">

  2034. <pre class="example">$ ffmpeg -f lavfi -i sine=r=44100 -f audiotoolbox -audio_device_index 2 -

  2035. </pre></div>

  2036. 

  2037. </li></ul>

  2038. 

  2039. <a name="caca"></a>

  2040. <h3 class="section">4.3 caca<span class="pull-right"><a class="anchor hidden-xs" href="#caca" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-caca" aria-hidden="true">TOC</a></span></h3>

  2041. 

  2042. <p>CACA output device.

  2043. </p>

  2044. <p>This output device allows one to show a video stream in CACA window.

  2045. Only one CACA window is allowed per application, so you can

  2046. have only one instance of this output device in an application.

  2047. </p>

  2048. <p>To enable this output device you need to configure FFmpeg with

  2049. <code>--enable-libcaca</code>.

  2050. libcaca is a graphics library that outputs text instead of pixels.

  2051. </p>

  2052. <p>For more information about libcaca, check:

  2053. <a href="http://caca.zoy.org/wiki/libcaca">http://caca.zoy.org/wiki/libcaca</a>

  2054. </p>

  2055. <a name="Options-22"></a>

  2056. <h4 class="subsection">4.3.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-22" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-22" aria-hidden="true">TOC</a></span></h4>

  2057. 

  2058. <dl compact="compact">

  2059. <dt><span><samp>window_title</samp></span></dt>

  2060. <dd><p>Set the CACA window title, if not specified default to the filename

  2061. specified for the output device.

  2062. </p>

  2063. </dd>

  2064. <dt><span><samp>window_size</samp></span></dt>

  2065. <dd><p>Set the CACA window size, can be a string of the form

  2066. <var>width</var>x<var>height</var> or a video size abbreviation.

  2067. If not specified it defaults to the size of the input video.

  2068. </p>

  2069. </dd>

  2070. <dt><span><samp>driver</samp></span></dt>

  2071. <dd><p>Set display driver.

  2072. </p>

  2073. </dd>

  2074. <dt><span><samp>algorithm</samp></span></dt>

  2075. <dd><p>Set dithering algorithm. Dithering is necessary

  2076. because the picture being rendered has usually far more colours than

  2077. the available palette.

  2078. The accepted values are listed with <code>-list_dither algorithms</code>.

  2079. </p>

  2080. </dd>

  2081. <dt><span><samp>antialias</samp></span></dt>

  2082. <dd><p>Set antialias method. Antialiasing smoothens the rendered

  2083. image and avoids the commonly seen staircase effect.

  2084. The accepted values are listed with <code>-list_dither antialiases</code>.

  2085. </p>

  2086. </dd>

  2087. <dt><span><samp>charset</samp></span></dt>

  2088. <dd><p>Set which characters are going to be used when rendering text.

  2089. The accepted values are listed with <code>-list_dither charsets</code>.

  2090. </p>

  2091. </dd>

  2092. <dt><span><samp>color</samp></span></dt>

  2093. <dd><p>Set color to be used when rendering text.

  2094. The accepted values are listed with <code>-list_dither colors</code>.

  2095. </p>

  2096. </dd>

  2097. <dt><span><samp>list_drivers</samp></span></dt>

  2098. <dd><p>If set to <samp>true</samp>, print a list of available drivers and exit.

  2099. </p>

  2100. </dd>

  2101. <dt><span><samp>list_dither</samp></span></dt>

  2102. <dd><p>List available dither options related to the argument.

  2103. The argument must be one of <code>algorithms</code>, <code>antialiases</code>,

  2104. <code>charsets</code>, <code>colors</code>.

  2105. </p></dd>

  2106. </dl>

  2107. 

  2108. <a name="Examples-10"></a>

  2109. <h4 class="subsection">4.3.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-10" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-10" aria-hidden="true">TOC</a></span></h4>

  2110. 

  2111. <ul>

  2112. <li> The following command shows the <code>ffmpeg</code> output is an

  2113. CACA window, forcing its size to 80x25:

  2114. <div class="example">

  2115. <pre class="example">ffmpeg -i INPUT -c:v rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -

  2116. </pre></div>

  2117. 

  2118. </li><li> Show the list of available drivers and exit:

  2119. <div class="example">

  2120. <pre class="example">ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -

  2121. </pre></div>

  2122. 

  2123. </li><li> Show the list of available dither colors and exit:

  2124. <div class="example">

  2125. <pre class="example">ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -

  2126. </pre></div>

  2127. </li></ul>

  2128. 

  2129. <a name="decklink-1"></a>

  2130. <h3 class="section">4.4 decklink<span class="pull-right"><a class="anchor hidden-xs" href="#decklink-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-decklink-1" aria-hidden="true">TOC</a></span></h3>

  2131. 

  2132. <p>The decklink output device provides playback capabilities for Blackmagic

  2133. DeckLink devices.

  2134. </p>

  2135. <p>To enable this output device, you need the Blackmagic DeckLink SDK and you

  2136. need to configure with the appropriate <code>--extra-cflags</code>

  2137. and <code>--extra-ldflags</code>.

  2138. On Windows, you need to run the IDL files through <code>widl</code>.

  2139. </p>

  2140. <p>DeckLink is very picky about the formats it supports. Pixel format is always

  2141. uyvy422, framerate, field order and video size must be determined for your

  2142. device with <code>-list_formats 1</code>. Audio sample rate is always 48 kHz.

  2143. </p>

  2144. <a name="Options-23"></a>

  2145. <h4 class="subsection">4.4.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-23" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-23" aria-hidden="true">TOC</a></span></h4>

  2146. 

  2147. <dl compact="compact">

  2148. <dt><span><samp>list_devices</samp></span></dt>

  2149. <dd><p>If set to <samp>true</samp>, print a list of devices and exit.

  2150. Defaults to <samp>false</samp>. This option is deprecated, please use the

  2151. <code>-sinks</code> option of ffmpeg to list the available output devices.

  2152. </p>

  2153. </dd>

  2154. <dt><span><samp>list_formats</samp></span></dt>

  2155. <dd><p>If set to <samp>true</samp>, print a list of supported formats and exit.

  2156. Defaults to <samp>false</samp>.

  2157. </p>

  2158. </dd>

  2159. <dt><span><samp>preroll</samp></span></dt>

  2160. <dd><p>Amount of time to preroll video in seconds.

  2161. Defaults to <samp>0.5</samp>.

  2162. </p>

  2163. </dd>

  2164. <dt><span><samp>duplex_mode</samp></span></dt>

  2165. <dd><p>Sets the decklink device duplex/profile mode. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>half</samp>&rsquo;, &lsquo;<samp>full</samp>&rsquo;,

  2166. &lsquo;<samp>one_sub_device_full</samp>&rsquo;, &lsquo;<samp>one_sub_device_half</samp>&rsquo;, &lsquo;<samp>two_sub_device_full</samp>&rsquo;,

  2167. &lsquo;<samp>four_sub_device_half</samp>&rsquo;

  2168. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  2169. </p>

  2170. <p>Note: DeckLink SDK 11.0 have replaced the duplex property by a profile property.

  2171. For the DeckLink Duo 2 and DeckLink Quad 2, a profile is shared between any 2

  2172. sub-devices that utilize the same connectors. For the DeckLink 8K Pro, a profile

  2173. is shared between all 4 sub-devices. So DeckLink 8K Pro support four profiles.

  2174. </p>

  2175. <p>Valid profile modes for DeckLink 8K Pro(with DeckLink SDK &gt;= 11.0):

  2176. &lsquo;<samp>one_sub_device_full</samp>&rsquo;, &lsquo;<samp>one_sub_device_half</samp>&rsquo;, &lsquo;<samp>two_sub_device_full</samp>&rsquo;,

  2177. &lsquo;<samp>four_sub_device_half</samp>&rsquo;

  2178. </p>

  2179. <p>Valid profile modes for DeckLink Quad 2 and DeckLink Duo 2:

  2180. &lsquo;<samp>half</samp>&rsquo;, &lsquo;<samp>full</samp>&rsquo;

  2181. </p>

  2182. </dd>

  2183. <dt><span><samp>timing_offset</samp></span></dt>

  2184. <dd><p>Sets the genlock timing pixel offset on the used output.

  2185. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  2186. </p>

  2187. </dd>

  2188. <dt><span><samp>link</samp></span></dt>

  2189. <dd><p>Sets the SDI video link configuration on the used output. Must be

  2190. &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>single</samp>&rsquo; link SDI, &lsquo;<samp>dual</samp>&rsquo; link SDI or &lsquo;<samp>quad</samp>&rsquo; link

  2191. SDI.

  2192. Defaults to &lsquo;<samp>unset</samp>&rsquo;.

  2193. </p>

  2194. </dd>

  2195. <dt><span><samp>sqd</samp></span></dt>

  2196. <dd><p>Enable Square Division Quad Split mode for Quad-link SDI output.

  2197. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>true</samp>&rsquo; or &lsquo;<samp>false</samp>&rsquo;.

  2198. Defaults to <samp>unset</samp>.

  2199. </p>

  2200. </dd>

  2201. <dt><span><samp>level_a</samp></span></dt>

  2202. <dd><p>Enable SMPTE Level A mode on the used output.

  2203. Must be &lsquo;<samp>unset</samp>&rsquo;, &lsquo;<samp>true</samp>&rsquo; or &lsquo;<samp>false</samp>&rsquo;.

  2204. Defaults to <samp>unset</samp>.

  2205. </p>

  2206. </dd>

  2207. </dl>

  2208. 

  2209. <a name="Examples-11"></a>

  2210. <h4 class="subsection">4.4.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-11" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-11" aria-hidden="true">TOC</a></span></h4>

  2211. 

  2212. <ul>

  2213. <li> List output devices:

  2214. <div class="example">

  2215. <pre class="example">ffmpeg -sinks decklink

  2216. </pre></div>

  2217. 

  2218. </li><li> List supported formats:

  2219. <div class="example">

  2220. <pre class="example">ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'

  2221. </pre></div>

  2222. 

  2223. </li><li> Play video clip:

  2224. <div class="example">

  2225. <pre class="example">ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'

  2226. </pre></div>

  2227. 

  2228. </li><li> Play video clip with non-standard framerate or video size:

  2229. <div class="example">

  2230. <pre class="example">ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'

  2231. </pre></div>

  2232. 

  2233. </li></ul>

  2234. 

  2235. <a name="fbdev-1"></a>

  2236. <h3 class="section">4.5 fbdev<span class="pull-right"><a class="anchor hidden-xs" href="#fbdev-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-fbdev-1" aria-hidden="true">TOC</a></span></h3>

  2237. 

  2238. <p>Linux framebuffer output device.

  2239. </p>

  2240. <p>The Linux framebuffer is a graphic hardware-independent abstraction

  2241. layer to show graphics on a computer monitor, typically on the

  2242. console. It is accessed through a file device node, usually

  2243. <samp>/dev/fb0</samp>.

  2244. </p>

  2245. <p>For more detailed information read the file

  2246. <samp>Documentation/fb/framebuffer.txt</samp> included in the Linux source tree.

  2247. </p>

  2248. <a name="Options-24"></a>

  2249. <h4 class="subsection">4.5.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-24" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-24" aria-hidden="true">TOC</a></span></h4>

  2250. <dl compact="compact">

  2251. <dt><span><samp>xoffset</samp></span></dt>

  2252. <dt><span><samp>yoffset</samp></span></dt>

  2253. <dd><p>Set x/y coordinate of top left corner. Default is 0.

  2254. </p></dd>

  2255. </dl>

  2256. 

  2257. <a name="Examples-12"></a>

  2258. <h4 class="subsection">4.5.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-12" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-12" aria-hidden="true">TOC</a></span></h4>

  2259. <p>Play a file on framebuffer device <samp>/dev/fb0</samp>.

  2260. Required pixel format depends on current framebuffer settings.

  2261. </p><div class="example">

  2262. <pre class="example">ffmpeg -re -i INPUT -c:v rawvideo -pix_fmt bgra -f fbdev /dev/fb0

  2263. </pre></div>

  2264. 

  2265. <p>See also <a href="http://linux-fbdev.sourceforge.net/">http://linux-fbdev.sourceforge.net/</a>, and fbset(1).

  2266. </p>

  2267. <a name="opengl"></a>

  2268. <h3 class="section">4.6 opengl<span class="pull-right"><a class="anchor hidden-xs" href="#opengl" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-opengl" aria-hidden="true">TOC</a></span></h3>

  2269. <p>OpenGL output device.

  2270. </p>

  2271. <p>To enable this output device you need to configure FFmpeg with <code>--enable-opengl</code>.

  2272. </p>

  2273. <p>This output device allows one to render to OpenGL context.

  2274. Context may be provided by application or default SDL window is created.

  2275. </p>

  2276. <p>When device renders to external context, application must implement handlers for following messages:

  2277. <code>AV_DEV_TO_APP_CREATE_WINDOW_BUFFER</code> - create OpenGL context on current thread.

  2278. <code>AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER</code> - make OpenGL context current.

  2279. <code>AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER</code> - swap buffers.

  2280. <code>AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER</code> - destroy OpenGL context.

  2281. Application is also required to inform a device about current resolution by sending <code>AV_APP_TO_DEV_WINDOW_SIZE</code> message.

  2282. </p>

  2283. <a name="Options-25"></a>

  2284. <h4 class="subsection">4.6.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-25" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-25" aria-hidden="true">TOC</a></span></h4>

  2285. <dl compact="compact">

  2286. <dt><span><samp>background</samp></span></dt>

  2287. <dd><p>Set background color. Black is a default.

  2288. </p></dd>

  2289. <dt><span><samp>no_window</samp></span></dt>

  2290. <dd><p>Disables default SDL window when set to non-zero value.

  2291. Application must provide OpenGL context and both <code>window_size_cb</code> and <code>window_swap_buffers_cb</code> callbacks when set.

  2292. </p></dd>

  2293. <dt><span><samp>window_title</samp></span></dt>

  2294. <dd><p>Set the SDL window title, if not specified default to the filename specified for the output device.

  2295. Ignored when <samp>no_window</samp> is set.

  2296. </p></dd>

  2297. <dt><span><samp>window_size</samp></span></dt>

  2298. <dd><p>Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.

  2299. If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.

  2300. Mostly usable when <samp>no_window</samp> is not set.

  2301. </p>

  2302. </dd>

  2303. </dl>

  2304. 

  2305. <a name="Examples-13"></a>

  2306. <h4 class="subsection">4.6.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-13" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-13" aria-hidden="true">TOC</a></span></h4>

  2307. <p>Play a file on SDL window using OpenGL rendering:

  2308. </p><div class="example">

  2309. <pre class="example">ffmpeg  -i INPUT -f opengl &quot;window title&quot;

  2310. </pre></div>

  2311. 

  2312. <a name="oss-1"></a>

  2313. <h3 class="section">4.7 oss<span class="pull-right"><a class="anchor hidden-xs" href="#oss-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-oss-1" aria-hidden="true">TOC</a></span></h3>

  2314. 

  2315. <p>OSS (Open Sound System) output device.

  2316. </p>

  2317. <a name="pulse-1"></a>

  2318. <h3 class="section">4.8 pulse<span class="pull-right"><a class="anchor hidden-xs" href="#pulse-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-pulse-1" aria-hidden="true">TOC</a></span></h3>

  2319. 

  2320. <p>PulseAudio output device.

  2321. </p>

  2322. <p>To enable this output device you need to configure FFmpeg with <code>--enable-libpulse</code>.

  2323. </p>

  2324. <p>More information about PulseAudio can be found on <a href="http://www.pulseaudio.org">http://www.pulseaudio.org</a>

  2325. </p>

  2326. <a name="Options-26"></a>

  2327. <h4 class="subsection">4.8.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-26" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-26" aria-hidden="true">TOC</a></span></h4>

  2328. <dl compact="compact">

  2329. <dt><span><samp>server</samp></span></dt>

  2330. <dd><p>Connect to a specific PulseAudio server, specified by an IP address.

  2331. Default server is used when not provided.

  2332. </p>

  2333. </dd>

  2334. <dt><span><samp>name</samp></span></dt>

  2335. <dd><p>Specify the application name PulseAudio will use when showing active clients,

  2336. by default it is the <code>LIBAVFORMAT_IDENT</code> string.

  2337. </p>

  2338. </dd>

  2339. <dt><span><samp>stream_name</samp></span></dt>

  2340. <dd><p>Specify the stream name PulseAudio will use when showing active streams,

  2341. by default it is set to the specified output name.

  2342. </p>

  2343. </dd>

  2344. <dt><span><samp>device</samp></span></dt>

  2345. <dd><p>Specify the device to use. Default device is used when not provided.

  2346. List of output devices can be obtained with command <code>pactl list sinks</code>.

  2347. </p>

  2348. </dd>

  2349. <dt><span><samp>buffer_size</samp></span></dt>

  2350. <dt><span><samp>buffer_duration</samp></span></dt>

  2351. <dd><p>Control the size and duration of the PulseAudio buffer. A small buffer

  2352. gives more control, but requires more frequent updates.

  2353. </p>

  2354. <p><samp>buffer_size</samp> specifies size in bytes while

  2355. <samp>buffer_duration</samp> specifies duration in milliseconds.

  2356. </p>

  2357. <p>When both options are provided then the highest value is used

  2358. (duration is recalculated to bytes using stream parameters). If they

  2359. are set to 0 (which is default), the device will use the default

  2360. PulseAudio duration value. By default PulseAudio set buffer duration

  2361. to around 2 seconds.

  2362. </p>

  2363. </dd>

  2364. <dt><span><samp>prebuf</samp></span></dt>

  2365. <dd><p>Specify pre-buffering size in bytes. The server does not start with

  2366. playback before at least <samp>prebuf</samp> bytes are available in the

  2367. buffer. By default this option is initialized to the same value as

  2368. <samp>buffer_size</samp> or <samp>buffer_duration</samp> (whichever is bigger).

  2369. </p>

  2370. </dd>

  2371. <dt><span><samp>minreq</samp></span></dt>

  2372. <dd><p>Specify minimum request size in bytes. The server does not request less

  2373. than <samp>minreq</samp> bytes from the client, instead waits until the buffer

  2374. is free enough to request more bytes at once. It is recommended to not set

  2375. this option, which will initialize this to a value that is deemed sensible

  2376. by the server.

  2377. </p>

  2378. </dd>

  2379. </dl>

  2380. 

  2381. <a name="Examples-14"></a>

  2382. <h4 class="subsection">4.8.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-14" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-14" aria-hidden="true">TOC</a></span></h4>

  2383. <p>Play a file on default device on default server:

  2384. </p><div class="example">

  2385. <pre class="example">ffmpeg  -i INPUT -f pulse &quot;stream name&quot;

  2386. </pre></div>

  2387. 

  2388. <a name="sdl"></a>

  2389. <h3 class="section">4.9 sdl<span class="pull-right"><a class="anchor hidden-xs" href="#sdl" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-sdl" aria-hidden="true">TOC</a></span></h3>

  2390. 

  2391. <p>SDL (Simple DirectMedia Layer) output device.

  2392. </p>

  2393. <p>&quot;sdl2&quot; can be used as alias for &quot;sdl&quot;.

  2394. </p>

  2395. <p>This output device allows one to show a video stream in an SDL

  2396. window. Only one SDL window is allowed per application, so you can

  2397. have only one instance of this output device in an application.

  2398. </p>

  2399. <p>To enable this output device you need libsdl installed on your system

  2400. when configuring your build.

  2401. </p>

  2402. <p>For more information about SDL, check:

  2403. <a href="http://www.libsdl.org/">http://www.libsdl.org/</a>

  2404. </p>

  2405. <a name="Options-27"></a>

  2406. <h4 class="subsection">4.9.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-27" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-27" aria-hidden="true">TOC</a></span></h4>

  2407. 

  2408. <dl compact="compact">

  2409. <dt><span><samp>window_title</samp></span></dt>

  2410. <dd><p>Set the SDL window title, if not specified default to the filename

  2411. specified for the output device.

  2412. </p>

  2413. </dd>

  2414. <dt><span><samp>icon_title</samp></span></dt>

  2415. <dd><p>Set the name of the iconified SDL window, if not specified it is set

  2416. to the same value of <var>window_title</var>.

  2417. </p>

  2418. </dd>

  2419. <dt><span><samp>window_size</samp></span></dt>

  2420. <dd><p>Set the SDL window size, can be a string of the form

  2421. <var>width</var>x<var>height</var> or a video size abbreviation.

  2422. If not specified it defaults to the size of the input video,

  2423. downscaled according to the aspect ratio.

  2424. </p>

  2425. </dd>

  2426. <dt><span><samp>window_x</samp></span></dt>

  2427. <dt><span><samp>window_y</samp></span></dt>

  2428. <dd><p>Set the position of the window on the screen.

  2429. </p>

  2430. </dd>

  2431. <dt><span><samp>window_fullscreen</samp></span></dt>

  2432. <dd><p>Set fullscreen mode when non-zero value is provided.

  2433. Default value is zero.

  2434. </p>

  2435. </dd>

  2436. <dt><span><samp>window_enable_quit</samp></span></dt>

  2437. <dd><p>Enable quit action (using window button or keyboard key)

  2438. when non-zero value is provided.

  2439. Default value is 1 (enable quit action)

  2440. </p></dd>

  2441. </dl>

  2442. 

  2443. <a name="Interactive-commands"></a>

  2444. <h4 class="subsection">4.9.2 Interactive commands<span class="pull-right"><a class="anchor hidden-xs" href="#Interactive-commands" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Interactive-commands" aria-hidden="true">TOC</a></span></h4>

  2445. 

  2446. <p>The window created by the device can be controlled through the

  2447. following interactive commands.

  2448. </p>

  2449. <dl compact="compact">

  2450. <dt><span><tt class="key">q, ESC</tt></span></dt>

  2451. <dd><p>Quit the device immediately.

  2452. </p></dd>

  2453. </dl>

  2454. 

  2455. <a name="Examples-15"></a>

  2456. <h4 class="subsection">4.9.3 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-15" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-15" aria-hidden="true">TOC</a></span></h4>

  2457. 

  2458. <p>The following command shows the <code>ffmpeg</code> output is an

  2459. SDL window, forcing its size to the qcif format:

  2460. </p><div class="example">

  2461. <pre class="example">ffmpeg -i INPUT -c:v rawvideo -pix_fmt yuv420p -window_size qcif -f sdl &quot;SDL output&quot;

  2462. </pre></div>

  2463. 

  2464. <a name="sndio-1"></a>

  2465. <h3 class="section">4.10 sndio<span class="pull-right"><a class="anchor hidden-xs" href="#sndio-1" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-sndio-1" aria-hidden="true">TOC</a></span></h3>

  2466. 

  2467. <p>sndio audio output device.

  2468. </p>

  2469. <a name="v4l2"></a>

  2470. <h3 class="section">4.11 v4l2<span class="pull-right"><a class="anchor hidden-xs" href="#v4l2" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-v4l2" aria-hidden="true">TOC</a></span></h3>

  2471. 

  2472. <p>Video4Linux2 output device.

  2473. </p>

  2474. <a name="xv"></a>

  2475. <h3 class="section">4.12 xv<span class="pull-right"><a class="anchor hidden-xs" href="#xv" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-xv" aria-hidden="true">TOC</a></span></h3>

  2476. 

  2477. <p>XV (XVideo) output device.

  2478. </p>

  2479. <p>This output device allows one to show a video stream in a X Window System

  2480. window.

  2481. </p>

  2482. <a name="Options-28"></a>

  2483. <h4 class="subsection">4.12.1 Options<span class="pull-right"><a class="anchor hidden-xs" href="#Options-28" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Options-28" aria-hidden="true">TOC</a></span></h4>

  2484. 

  2485. <dl compact="compact">

  2486. <dt><span><samp>display_name</samp></span></dt>

  2487. <dd><p>Specify the hardware display name, which determines the display and

  2488. communications domain to be used.

  2489. </p>

  2490. <p>The display name or DISPLAY environment variable can be a string in

  2491. the format <var>hostname</var>[:<var>number</var>[.<var>screen_number</var>]].

  2492. </p>

  2493. <p><var>hostname</var> specifies the name of the host machine on which the

  2494. display is physically attached. <var>number</var> specifies the number of

  2495. the display server on that host machine. <var>screen_number</var> specifies

  2496. the screen to be used on that server.

  2497. </p>

  2498. <p>If unspecified, it defaults to the value of the DISPLAY environment

  2499. variable.

  2500. </p>

  2501. <p>For example, <code>dual-headed:0.1</code> would specify screen 1 of display

  2502. 0 on the machine named &ldquo;dual-headed&rdquo;.

  2503. </p>

  2504. <p>Check the X11 specification for more detailed information about the

  2505. display name format.

  2506. </p>

  2507. </dd>

  2508. <dt><span><samp>window_id</samp></span></dt>

  2509. <dd><p>When set to non-zero value then device doesn&rsquo;t create new window,

  2510. but uses existing one with provided <var>window_id</var>. By default

  2511. this options is set to zero and device creates its own window.

  2512. </p>

  2513. </dd>

  2514. <dt><span><samp>window_size</samp></span></dt>

  2515. <dd><p>Set the created window size, can be a string of the form

  2516. <var>width</var>x<var>height</var> or a video size abbreviation. If not

  2517. specified it defaults to the size of the input video.

  2518. Ignored when <var>window_id</var> is set.

  2519. </p>

  2520. </dd>

  2521. <dt><span><samp>window_x</samp></span></dt>

  2522. <dt><span><samp>window_y</samp></span></dt>

  2523. <dd><p>Set the X and Y window offsets for the created window. They are both

  2524. set to 0 by default. The values may be ignored by the window manager.

  2525. Ignored when <var>window_id</var> is set.

  2526. </p>

  2527. </dd>

  2528. <dt><span><samp>window_title</samp></span></dt>

  2529. <dd><p>Set the window title, if not specified default to the filename

  2530. specified for the output device. Ignored when <var>window_id</var> is set.

  2531. </p></dd>

  2532. </dl>

  2533. 

  2534. <p>For more information about XVideo see <a href="http://www.x.org/">http://www.x.org/</a>.

  2535. </p>

  2536. <a name="Examples-16"></a>

  2537. <h4 class="subsection">4.12.2 Examples<span class="pull-right"><a class="anchor hidden-xs" href="#Examples-16" aria-hidden="true">#</a> <a class="anchor hidden-xs"href="#toc-Examples-16" aria-hidden="true">TOC</a></span></h4>

  2538. 

  2539. <ul>

  2540. <li> Decode, display and encode video input with <code>ffmpeg</code> at the

  2541. same time:

  2542. <div class="example">

  2543. <pre class="example">ffmpeg -i INPUT OUTPUT -f xv display

  2544. </pre></div>

  2545. 

  2546. </li><li> Decode and display the input video to multiple X11 windows:

  2547. <div class="example">

  2548. <pre class="example">ffmpeg -i INPUT -f xv normal -vf negate -f xv negated

  2549. </pre></div>

  2550. </li></ul>

  2551. 

  2552. 

  2553. <a name="See-Also"></a>

  2554. <h2 class="chapter">5 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>

  2555. 

  2556. <p><a href="ffmpeg.html">ffmpeg</a>, <a href="ffplay.html">ffplay</a>, <a href="ffprobe.html">ffprobe</a>,

  2557. <a href="libavdevice.html">libavdevice</a>

  2558. </p>

  2559. 

  2560. <a name="Authors"></a>

  2561. <h2 class="chapter">6 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>

  2562. 

  2563. <p>The FFmpeg developers.

  2564. </p>

  2565. <p>For details about the authorship, see the Git history of the project

  2566. (https://git.ffmpeg.org/ffmpeg), e.g. by typing the command

  2567. <code>git log</code> in the FFmpeg source directory, or browsing the

  2568. online repository at <a href="https://git.ffmpeg.org/ffmpeg">https://git.ffmpeg.org/ffmpeg</a>.

  2569. </p>

  2570. <p>Maintainers for the specific components are listed in the file

  2571. <samp>MAINTAINERS</samp> in the source code tree.

  2572. </p>

  2573. 

  2574.       <p style="font-size: small;">

  2575.         This document was generated using <a href="https://www.gnu.org/software/texinfo/"><em>makeinfo</em></a>.

  2576.       </p>

  2577.     </div>

  2578.   </body>

  2579. </html>