FFmpeg: libavformat/rtpdec_mpegts.c Source File

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libavformat

rtpdec_mpegts.c

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1 /*

2 * RTP MPEG2TS depacketizer

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 */

22 #include "libavutil/attributes.h"

23 #include "mpegts.h"

24 #include "rtpdec_formats.h"

26 struct PayloadContext {

27 struct MpegTSContext *ts;

28 int read_buf_index;

29 int read_buf_size;

30 uint8_t buf[RTP_MAX_PACKET_LENGTH];

31 };

33 static void mpegts_close_context(PayloadContext *data)

34 {

35 if (!data)

36 return;

37 if (data->ts)

38 avpriv_mpegts_parse_close(data->ts);

39 }

41 static av_cold int mpegts_init(AVFormatContext *ctx, int st_index,

42 PayloadContext *data)

43 {

44 data->ts = avpriv_mpegts_parse_open(ctx);

45 if (!data->ts)

46 return AVERROR(ENOMEM);

47 return 0;

48 }

50 static int mpegts_handle_packet(AVFormatContext *ctx, PayloadContext *data,

51 AVStream *st, AVPacket *pkt, uint32_t *timestamp,

52 const uint8_t *buf, int len, uint16_t seq,

53 int flags)

54 {

55 int ret;

57 // We don't want to use the RTP timestamps at all. If the mpegts demuxer

58 // doesn't set any pts/dts, the generic rtpdec code shouldn't try to

59 // fill it in either, since the mpegts and RTP timestamps are in totally

60 // different ranges.

61 *timestamp = RTP_NOTS_VALUE;

63 if (!buf) {

64 if (data->read_buf_index >= data->read_buf_size)

65 return AVERROR(EAGAIN);

66 ret = avpriv_mpegts_parse_packet(data->ts, pkt, data->buf + data->read_buf_index,

67 data->read_buf_size - data->read_buf_index);

68 if (ret < 0)

69 return AVERROR(EAGAIN);

70 data->read_buf_index += ret;

71 if (data->read_buf_index < data->read_buf_size)

72 return 1;

73 else

74 return 0;

75 }

77 ret = avpriv_mpegts_parse_packet(data->ts, pkt, buf, len);

78 /* The only error that can be returned from avpriv_mpegts_parse_packet

79 * is "no more data to return from the provided buffer", so return

80 * AVERROR(EAGAIN) for all errors */

81 if (ret < 0)

82 return AVERROR(EAGAIN);

83 if (ret < len) {

84 data->read_buf_size = FFMIN(len - ret, sizeof(data->buf));

85 memcpy(data->buf, buf + ret, data->read_buf_size);

86 data->read_buf_index = 0;

87 return 1;

88 }

89 return 0;

90 }

92 const RTPDynamicProtocolHandler ff_mpegts_dynamic_handler = {

93 .codec_type = AVMEDIA_TYPE_DATA,

94 .priv_data_size = sizeof(PayloadContext),

95 .parse_packet = mpegts_handle_packet,

96 .init = mpegts_init,

97 .close = mpegts_close_context,

98 .static_payload_id = 33,

99 };

AVERROR

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

mpegts.h

avpriv_mpegts_parse_packet

int avpriv_mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt, const uint8_t *buf, int len)

Definition: mpegts.c:3391

rtpdec_formats.h

data

const char data[16]

Definition: mxf.c:143

mpegts_init

static av_cold int mpegts_init(AVFormatContext *ctx, int st_index, PayloadContext *data)

Definition: rtpdec_mpegts.c:41

init

static int init

Definition: av_tx.c:47

PayloadContext::read_buf_index

int read_buf_index

Definition: rtpdec_mpegts.c:28

avpriv_mpegts_parse_close

void avpriv_mpegts_parse_close(MpegTSContext *ts)

Definition: mpegts.c:3416

pkt

AVPacket * pkt

Definition: movenc.c:59

av_cold

#define av_cold

Definition: attributes.h:90

RTP_NOTS_VALUE

#define RTP_NOTS_VALUE

Definition: rtpdec.h:41

ctx

AVFormatContext * ctx

Definition: movenc.c:48

AVMEDIA_TYPE_DATA

@ AVMEDIA_TYPE_DATA

Opaque data information usually continuous.

Definition: avutil.h:203

AVFormatContext

Format I/O context.

Definition: avformat.h:1200

MpegTSContext

Definition: mpegts.c:128

attributes.h

PayloadContext::read_buf_size

int read_buf_size

Definition: rtpdec_mpegts.c:29

FFMIN

#define FFMIN(a, b)

Definition: macros.h:49

len

int len

Definition: vorbis_enc_data.h:426

ff_mpegts_dynamic_handler

const RTPDynamicProtocolHandler ff_mpegts_dynamic_handler

Definition: rtpdec_mpegts.c:92

ret

Definition: filter_design.txt:187

AVStream

Stream structure.

Definition: avformat.h:935

RTP_MAX_PACKET_LENGTH

#define RTP_MAX_PACKET_LENGTH

Definition: rtpdec.h:37

PayloadContext::buf

uint8_t * buf

the temporary storage buffer

Definition: rtpdec_asf.c:183

RTPDynamicProtocolHandler::codec_type

enum AVMediaType codec_type

Definition: rtpdec.h:118

mpegts_handle_packet

static int mpegts_handle_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_mpegts.c:50

avpriv_mpegts_parse_open

MpegTSContext * avpriv_mpegts_parse_open(AVFormatContext *s)

Definition: mpegts.c:3370

parse_packet

static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index, int flush)

Parse a packet, add all split parts to parse_queue.

Definition: demux.c:1105

AVPacket

This structure stores compressed data.

Definition: packet.h:350

flags