stream-deploy/ZLM/3rdpart/media-server/librtp/payload/rtp-ps-unpack.c

70 lines
2.2 KiB
C++

/// RFC2250 2. Encapsulation of MPEG System and Transport Streams (p3)
#include "rtp-packet.h"
#include "rtp-payload-helper.h"
#include "rtp-payload-internal.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <errno.h>
// Pack start code
static const uint8_t s_mpeg2_packet_start[] = {0x00, 0x00, 0x01, 0xBA};
static int rtp_decode_ps(void* p, const void* packet, int bytes)
{
struct rtp_packet_t pkt;
struct rtp_payload_helper_t *helper;
helper = (struct rtp_payload_helper_t *)p;
if (!helper || 0 != rtp_packet_deserialize(&pkt, packet, bytes))
return -EINVAL;
// if(-1 == helper->flags)
// {
// if(pkt.payloadlen < sizeof(s_mpeg2_packet_start) + 2 || 0 != memcmp(s_mpeg2_packet_start, pkt.payload, sizeof(s_mpeg2_packet_start)))
// return 0; // packet discard, wait for first packet
// }
// 2.1 RTP header usage(p4)
// M bit: Set to 1 whenever the timestamp is discontinuous. (such as
// might happen when a sender switches from one data
// source to another).This allows the receiver and any
// intervening RTP mixers or translators that are synchronizing
// to the flow to ignore the difference between this timestamp
// and any previous timestamp in their clock phase detectors.
// if (pkt.rtp.m)
// {
// //TODO: test
// // new frame start
// helper->size = 0; // discard previous packets
// helper->lost = 0;
// helper->flags |= RTP_PAYLOAD_FLAG_PACKET_LOST; // notify source changed
// helper->seq = (uint16_t)pkt.rtp.seq;
// helper->timestamp = pkt.rtp.timestamp;
// }
// else
{
rtp_payload_check(helper, &pkt);
}
// ignore RTP M bit
if (pkt.payloadlen > sizeof(s_mpeg2_packet_start) && 0 == memcmp(s_mpeg2_packet_start, pkt.payload, sizeof(s_mpeg2_packet_start)))
rtp_payload_onframe(helper); // new frame/access start
rtp_payload_write(helper, &pkt);
return helper->lost ? 0 : 1; // packet handled
}
struct rtp_payload_decode_t *rtp_ps_decode(void)
{
static struct rtp_payload_decode_t decode = {
rtp_payload_helper_create,
rtp_payload_helper_destroy,
rtp_decode_ps,
};
return &decode;
}