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rtpdec_mpeg12.c
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1 /*
2  * Common code for the RTP depacketization of MPEG-1/2 formats.
3  * Copyright (c) 2002 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "rtpdec_formats.h"
23 #include "libavutil/intreadwrite.h"
24 
25 static int mpeg_init(AVFormatContext *ctx, int st_index, PayloadContext *data)
26 {
27  if (st_index < 0)
28  return 0;
29  ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
30  return 0;
31 }
32 
34  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
35  const uint8_t *buf, int len, uint16_t seq,
36  int flags)
37 {
38  unsigned int h;
39  if (len <= 4)
40  return AVERROR_INVALIDDATA;
41  h = AV_RB32(buf);
42  buf += 4;
43  len -= 4;
44  if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && h & (1 << 26)) {
45  /* MPEG-2 */
46  if (len <= 4)
47  return AVERROR_INVALIDDATA;
48  buf += 4;
49  len -= 4;
50  }
51  if (av_new_packet(pkt, len) < 0)
52  return AVERROR(ENOMEM);
53  memcpy(pkt->data, buf, len);
54  pkt->stream_index = st->index;
55  return 0;
56 }
57 
60  .codec_id = AV_CODEC_ID_MP3,
61  .init = mpeg_init,
62  .parse_packet = mpeg_parse_packet,
63  .static_payload_id = 14,
64 };
65 
68  .codec_id = AV_CODEC_ID_MPEG2VIDEO,
69  .init = mpeg_init,
70  .parse_packet = mpeg_parse_packet,
71  .static_payload_id = 32,
72 };