FFmpeg
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 "libavutil/attributes.h"
23 #include "libavutil/intreadwrite.h"
24 #include "rtpdec_formats.h"
25 
27  AVStream *st, AVPacket *pkt, uint32_t *timestamp,
28  const uint8_t *buf, int len, uint16_t seq,
29  int flags)
30 {
31  unsigned int h;
32  if (len <= 4)
33  return AVERROR_INVALIDDATA;
34  h = AV_RB32(buf);
35  buf += 4;
36  len -= 4;
37  if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && h & (1 << 26)) {
38  /* MPEG-2 */
39  if (len <= 4)
40  return AVERROR_INVALIDDATA;
41  buf += 4;
42  len -= 4;
43  }
44  if (av_new_packet(pkt, len) < 0)
45  return AVERROR(ENOMEM);
46  memcpy(pkt->data, buf, len);
47  pkt->stream_index = st->index;
48  return 0;
49 }
50 
53  .codec_id = AV_CODEC_ID_MP3,
54  .need_parsing = AVSTREAM_PARSE_FULL,
55  .parse_packet = mpeg_parse_packet,
56  .static_payload_id = 14,
57 };
58 
61  .codec_id = AV_CODEC_ID_MPEG2VIDEO,
62  .need_parsing = AVSTREAM_PARSE_FULL,
63  .parse_packet = mpeg_parse_packet,
64  .static_payload_id = 32,
65 };
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
RTP/JPEG specific private data.
Definition: rdt.c:83
int index
stream index in AVFormatContext
Definition: avformat.h:882
const RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler
Definition: rtpdec_mpeg12.c:59
static AVPacket pkt
enum AVMediaType codec_type
Definition: rtpdec.h:117
Macro definitions for various function/variable attributes.
Format I/O context.
Definition: avformat.h:1358
uint8_t
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:87
uint8_t * data
Definition: avcodec.h:1477
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
const RTPDynamicProtocolHandler ff_mpeg_audio_dynamic_handler
Definition: rtpdec_mpeg12.c:51
preferred ID for decoding MPEG audio layer 1, 2 or 3
Definition: avcodec.h:565
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
static int mpeg_parse_packet(AVFormatContext *ctx, PayloadContext *data, AVStream *st, AVPacket *pkt, uint32_t *timestamp, const uint8_t *buf, int len, uint16_t seq, int flags)
Definition: rtpdec_mpeg12.c:26
AVFormatContext * ctx
Definition: movenc.c:48
preferred ID for MPEG-1/2 video decoding
Definition: avcodec.h:220
Stream structure.
Definition: avformat.h:881
void * buf
Definition: avisynth_c.h:766
#define flags(name, subs,...)
Definition: cbs_av1.c:561
full parsing and repack
Definition: avformat.h:800
int len
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
This structure stores compressed data.
Definition: avcodec.h:1454