xref: /third_party/ffmpeg/libavformat/lvfdec.c (revision cabdff1a)
1/*
2 * LVF demuxer
3 * Copyright (c) 2012 Paul B Mahol
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/intreadwrite.h"
23#include "avformat.h"
24#include "riff.h"
25
26static int lvf_probe(const AVProbeData *p)
27{
28    if (AV_RL32(p->buf) != MKTAG('L', 'V', 'F', 'F'))
29        return 0;
30
31    if (!AV_RL32(p->buf + 16) || AV_RL32(p->buf + 16) > 256)
32        return AVPROBE_SCORE_MAX / 8;
33
34    return AVPROBE_SCORE_EXTENSION;
35}
36
37static int lvf_read_header(AVFormatContext *s)
38{
39    AVStream *st;
40    int64_t next_offset;
41    unsigned size, nb_streams, id;
42
43    avio_skip(s->pb, 16);
44    nb_streams = avio_rl32(s->pb);
45    if (!nb_streams)
46        return AVERROR_INVALIDDATA;
47    if (nb_streams > 2) {
48        avpriv_request_sample(s, "%d streams", nb_streams);
49        return AVERROR_PATCHWELCOME;
50    }
51
52    avio_skip(s->pb, 1012);
53
54    while (!avio_feof(s->pb)) {
55        id          = avio_rl32(s->pb);
56        size        = avio_rl32(s->pb);
57        next_offset = avio_tell(s->pb) + size;
58
59        switch (id) {
60        case MKTAG('0', '0', 'f', 'm'):
61            st = avformat_new_stream(s, 0);
62            if (!st)
63                return AVERROR(ENOMEM);
64
65            st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
66            avio_skip(s->pb, 4);
67            st->codecpar->width      = avio_rl32(s->pb);
68            st->codecpar->height     = avio_rl32(s->pb);
69            avio_skip(s->pb, 4);
70            st->codecpar->codec_tag  = avio_rl32(s->pb);
71            st->codecpar->codec_id   = ff_codec_get_id(ff_codec_bmp_tags,
72                                                       st->codecpar->codec_tag);
73            avpriv_set_pts_info(st, 32, 1, 1000);
74            break;
75        case MKTAG('0', '1', 'f', 'm'):
76            st = avformat_new_stream(s, 0);
77            if (!st)
78                return AVERROR(ENOMEM);
79
80            st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
81            st->codecpar->codec_tag   = avio_rl16(s->pb);
82            st->codecpar->ch_layout.nb_channels = avio_rl16(s->pb);
83            st->codecpar->sample_rate = avio_rl16(s->pb);
84            avio_skip(s->pb, 8);
85            st->codecpar->bits_per_coded_sample = avio_r8(s->pb);
86            st->codecpar->codec_id    = ff_codec_get_id(ff_codec_wav_tags,
87                                                        st->codecpar->codec_tag);
88            avpriv_set_pts_info(st, 32, 1, 1000);
89            break;
90        case 0:
91            avio_seek(s->pb, 2048 + 8, SEEK_SET);
92            return 0;
93        default:
94            avpriv_request_sample(s, "id %d", id);
95            return AVERROR_PATCHWELCOME;
96        }
97
98        avio_seek(s->pb, next_offset, SEEK_SET);
99    }
100
101    return AVERROR_EOF;
102}
103
104static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt)
105{
106    unsigned size, flags, timestamp, id;
107    int64_t pos;
108    int ret, is_video = 0;
109    int stream_index;
110
111    pos = avio_tell(s->pb);
112    while (!avio_feof(s->pb)) {
113        id    = avio_rl32(s->pb);
114        size  = avio_rl32(s->pb);
115
116        if (size == 0xFFFFFFFFu)
117            return AVERROR_EOF;
118
119        switch (id) {
120        case MKTAG('0', '0', 'd', 'c'):
121            is_video = 1;
122        case MKTAG('0', '1', 'w', 'b'):
123            if (size < 8)
124                return AVERROR_INVALIDDATA;
125            stream_index = is_video ? 0 : 1;
126            if (stream_index >= s->nb_streams)
127                return AVERROR_INVALIDDATA;
128            timestamp = avio_rl32(s->pb);
129            flags = avio_rl32(s->pb);
130            ret = av_get_packet(s->pb, pkt, size - 8);
131            if (flags & (1 << 12))
132                pkt->flags |= AV_PKT_FLAG_KEY;
133            pkt->stream_index = stream_index;
134            pkt->pts          = timestamp;
135            pkt->pos          = pos;
136            return ret;
137        default:
138            ret = avio_skip(s->pb, size);
139        }
140
141        if (ret < 0)
142            return ret;
143    }
144
145    return AVERROR_EOF;
146}
147
148const AVInputFormat ff_lvf_demuxer = {
149    .name        = "lvf",
150    .long_name   = NULL_IF_CONFIG_SMALL("LVF"),
151    .read_probe  = lvf_probe,
152    .read_header = lvf_read_header,
153    .read_packet = lvf_read_packet,
154    .extensions  = "lvf",
155    .flags       = AVFMT_GENERIC_INDEX,
156};
157