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 PayloadContext *mpegts_new_context(void)

34 {

35 return av_mallocz(sizeof(PayloadContext));

36 }

38 static void mpegts_free_context(PayloadContext *data)

39 {

40 if (!data)

41 return;

42 if (data->ts)

43 ff_mpegts_parse_close(data->ts);

44 av_free(data);

45 }

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

48 PayloadContext *data)

49 {

50 data->ts = ff_mpegts_parse_open(ctx);

51 if (!data->ts)

52 return AVERROR(ENOMEM);

53 return 0;

54 }

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

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

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

59 int flags)

60 {

61 int ret;

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

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

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

66 // different ranges.

67 *timestamp = RTP_NOTS_VALUE;

69 if (!data->ts)

70 return AVERROR(EINVAL);

72 if (!buf) {

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

74 return AVERROR(EAGAIN);

75 ret = ff_mpegts_parse_packet(data->ts, pkt, data->buf + data->read_buf_index,

76 data->read_buf_size - data->read_buf_index);

77 if (ret < 0)

78 return AVERROR(EAGAIN);

79 data->read_buf_index += ret;

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

81 return 1;

82 else

83 return 0;

84 }

86 ret = ff_mpegts_parse_packet(data->ts, pkt, buf, len);

87 /* The only error that can be returned from ff_mpegts_parse_packet

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

89 * AVERROR(EAGAIN) for all errors */

90 if (ret < 0)

91 return AVERROR(EAGAIN);

92 if (ret < len) {

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

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

95 data->read_buf_index = 0;

96 return 1;

97 }

98 return 0;

99 }

100

101 RTPDynamicProtocolHandler ff_mpegts_dynamic_handler = {

102 .codec_type = AVMEDIA_TYPE_DATA,

103 .parse_packet = mpegts_handle_packet,

104 .alloc = mpegts_new_context,

105 .init = mpegts_init,

106 .free = mpegts_free_context,

107 .static_payload_id = 33,

108 };

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