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FFmpeg/libavformat/lvfdec.c

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/*
* LVF demuxer
* Copyright (c) 2012 Paul B Mahol
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "riff.h"
static int lvf_probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) != MKTAG('L', 'V', 'F', 'F'))
return 0;
if (!AV_RL32(p->buf + 16) || AV_RL32(p->buf + 16) > 256)
return AVPROBE_SCORE_MAX / 8;
return AVPROBE_SCORE_EXTENSION;
}
static int lvf_read_header(AVFormatContext *s)
{
AVStream *st;
int64_t next_offset;
unsigned size, nb_streams, id;
avio_skip(s->pb, 16);
nb_streams = avio_rl32(s->pb);
if (!nb_streams)
return AVERROR_INVALIDDATA;
if (nb_streams > 2) {
avpriv_request_sample(s, "%d streams", nb_streams);
return AVERROR_PATCHWELCOME;
}
avio_skip(s->pb, 1012);
while (!avio_feof(s->pb)) {
id = avio_rl32(s->pb);
size = avio_rl32(s->pb);
next_offset = avio_tell(s->pb) + size;
switch (id) {
case MKTAG('0', '0', 'f', 'm'):
st = avformat_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
avio_skip(s->pb, 4);
st->codecpar->width = avio_rl32(s->pb);
st->codecpar->height = avio_rl32(s->pb);
avio_skip(s->pb, 4);
st->codecpar->codec_tag = avio_rl32(s->pb);
st->codecpar->codec_id = ff_codec_get_id(ff_codec_bmp_tags,
st->codecpar->codec_tag);
avpriv_set_pts_info(st, 32, 1, 1000);
break;
case MKTAG('0', '1', 'f', 'm'):
st = avformat_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_tag = avio_rl16(s->pb);
st->codecpar->ch_layout.nb_channels = avio_rl16(s->pb);
st->codecpar->sample_rate = avio_rl16(s->pb);
avio_skip(s->pb, 8);
st->codecpar->bits_per_coded_sample = avio_r8(s->pb);
st->codecpar->codec_id = ff_codec_get_id(ff_codec_wav_tags,
st->codecpar->codec_tag);
avpriv_set_pts_info(st, 32, 1, 1000);
break;
case 0:
avio_seek(s->pb, 2048 + 8, SEEK_SET);
return 0;
default:
avpriv_request_sample(s, "id %d", id);
return AVERROR_PATCHWELCOME;
}
avio_seek(s->pb, next_offset, SEEK_SET);
}
return AVERROR_EOF;
}
static int lvf_read_packet(AVFormatContext *s, AVPacket *pkt)
{
unsigned size, flags, timestamp, id;
int64_t pos;
int ret, is_video = 0;
int stream_index;
pos = avio_tell(s->pb);
while (!avio_feof(s->pb)) {
id = avio_rl32(s->pb);
size = avio_rl32(s->pb);
if (size == 0xFFFFFFFFu)
return AVERROR_EOF;
switch (id) {
case MKTAG('0', '0', 'd', 'c'):
is_video = 1;
case MKTAG('0', '1', 'w', 'b'):
if (size < 8)
return AVERROR_INVALIDDATA;
stream_index = is_video ? 0 : 1;
if (stream_index >= s->nb_streams)
return AVERROR_INVALIDDATA;
timestamp = avio_rl32(s->pb);
flags = avio_rl32(s->pb);
ret = av_get_packet(s->pb, pkt, size - 8);
if (flags & (1 << 12))
pkt->flags |= AV_PKT_FLAG_KEY;
pkt->stream_index = stream_index;
pkt->pts = timestamp;
pkt->pos = pos;
return ret;
default:
ret = avio_skip(s->pb, size);
}
if (ret < 0)
return ret;
}
return AVERROR_EOF;
}
const AVInputFormat ff_lvf_demuxer = {
.name = "lvf",
.long_name = NULL_IF_CONFIG_SMALL("LVF"),
.read_probe = lvf_probe,
.read_header = lvf_read_header,
.read_packet = lvf_read_packet,
.extensions = "lvf",
.flags = AVFMT_GENERIC_INDEX,
};