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
26static av_cold int mpeg_init(AVFormatContext *ctx, int st_index, PayloadContext *data)
27{
28    if (st_index < 0)
29        return 0;
30    ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
31    return 0;
32}
33
34static int mpeg_parse_packet(AVFormatContext *ctx, PayloadContext *data,
35                             AVStream *st, AVPacket *pkt, uint32_t *timestamp,
36                             const uint8_t *buf, int len, uint16_t seq,
37                             int flags)
38{
39    unsigned int h;
40    if (len <= 4)
41        return AVERROR_INVALIDDATA;
42    h    = AV_RB32(buf);
43    buf += 4;
44    len -= 4;
45    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && h & (1 << 26)) {
46        /* MPEG-2 */
47        if (len <= 4)
48            return AVERROR_INVALIDDATA;
49        buf += 4;
50        len -= 4;
51    }
52    if (av_new_packet(pkt, len) < 0)
53        return AVERROR(ENOMEM);
54    memcpy(pkt->data, buf, len);
55    pkt->stream_index = st->index;
56    return 0;
57}
58
59RTPDynamicProtocolHandler ff_mpeg_audio_dynamic_handler = {
60    .codec_type        = AVMEDIA_TYPE_AUDIO,
61    .codec_id          = AV_CODEC_ID_MP3,
62    .init              = mpeg_init,
63    .parse_packet      = mpeg_parse_packet,
64    .static_payload_id = 14,
65};
66
67RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler = {
68    .codec_type        = AVMEDIA_TYPE_VIDEO,
69    .codec_id          = AV_CODEC_ID_MPEG2VIDEO,
70    .init              = mpeg_init,
71    .parse_packet      = mpeg_parse_packet,
72    .static_payload_id = 32,
73};
74