1 /*
2 * RTP MPEG2TS depacketizer
3 * Copyright (c) 2003 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 "mpegts.h"
24 #include "rtpdec_formats.h"
25
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 };
32
mpegts_close_context(PayloadContext * data)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 }
40
mpegts_init(AVFormatContext * ctx,int st_index,PayloadContext * data)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 }
49
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)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;
56
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;
62
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 }
76
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 }
91
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 };
100