ffmpeg/libavformat/3dostr.c

169 lines
4.9 KiB
C

/*
* 3DO STR demuxer
* Copyright (c) 2015 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 "avformat.h"
#include "internal.h"
static int threedostr_probe(AVProbeData *p)
{
if (memcmp(p->buf, "CTRL", 4) &&
memcmp(p->buf, "SHDR", 4) &&
memcmp(p->buf, "SNDS", 4))
return 0;
return AVPROBE_SCORE_MAX / 3 * 2;
}
static int threedostr_read_header(AVFormatContext *s)
{
unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;
AVStream *st;
while (!avio_feof(s->pb) && !found_shdr) {
chunk = avio_rl32(s->pb);
size = avio_rb32(s->pb);
if (size < 8)
return AVERROR_INVALIDDATA;
size -= 8;
switch (chunk) {
case MKTAG('C','T','R','L'):
ctrl_size = size;
break;
case MKTAG('S','N','D','S'):
if (size < 56)
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 8);
if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 24);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->sample_rate = avio_rb32(s->pb);
st->codec->channels = avio_rb32(s->pb);
if (st->codec->channels <= 0)
return AVERROR_INVALIDDATA;
codec = avio_rl32(s->pb);
avio_skip(s->pb, 4);
if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)
st->duration = (avio_rb32(s->pb) - 1) / st->codec->channels;
else
st->duration = avio_rb32(s->pb) * 16 / st->codec->channels;
size -= 56;
found_shdr = 1;
break;
case MKTAG('S','H','D','R'):
if (size > 0x78) {
avio_skip(s->pb, 0x74);
size -= 0x78;
if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {
ctrl_size = avio_rb32(s->pb);
size -= 4;;
}
}
break;
default:
av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
break;
}
avio_skip(s->pb, size);
}
switch (codec) {
case MKTAG('S','D','X','2'):
st->codec->codec_id = AV_CODEC_ID_SDX2_DPCM;
st->codec->block_align = 1 * st->codec->channels;
break;
default:
avpriv_request_sample(s, "codec %X", codec);
return AVERROR_PATCHWELCOME;
}
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
return 0;
}
static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
{
unsigned chunk, size, found_ssmp = 0;
AVStream *st = s->streams[0];
int64_t pos;
int ret = 0;
while (!found_ssmp) {
if (avio_feof(s->pb))
return AVERROR_EOF;
pos = avio_tell(s->pb);
chunk = avio_rl32(s->pb);
size = avio_rb32(s->pb);
if (!size)
continue;
if (size < 8)
return AVERROR_INVALIDDATA;
size -= 8;
switch (chunk) {
case MKTAG('S','N','D','S'):
if (size <= 16)
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 8);
if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 4);
size -= 16;
ret = av_get_packet(s->pb, pkt, size);
pkt->pos = pos;
pkt->stream_index = 0;
pkt->duration = size / st->codec->channels;
size = 0;
found_ssmp = 1;
break;
default:
av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
break;
}
avio_skip(s->pb, size);
}
return ret;
}
AVInputFormat ff_threedostr_demuxer = {
.name = "3dostr",
.long_name = NULL_IF_CONFIG_SMALL("3DO STR"),
.read_probe = threedostr_probe,
.read_header = threedostr_read_header,
.read_packet = threedostr_read_packet,
.extensions = "str",
.flags = AVFMT_GENERIC_INDEX,
};