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
26struct 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
33static PayloadContext *mpegts_new_context(void)
34{
35    return av_mallocz(sizeof(PayloadContext));
36}
37
38static 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}
46
47static 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}
55
56static 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;
62
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;
68
69    if (!data->ts)
70        return AVERROR(EINVAL);
71
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    }
85
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
101RTPDynamicProtocolHandler 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};
109