ffmpeg/libavformat/dcstr.c

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/*
* DC 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 "demux.h"
#include "internal.h"
static int dcstr_probe(const AVProbeData *p)
{
if (p->buf_size < 224 || memcmp(p->buf + 213, "Sega Stream", 11))
return 0;
return AVPROBE_SCORE_MAX;
}
static int dcstr_read_header(AVFormatContext *s)
{
unsigned codec, align;
int mult;
AVStream *st;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->ch_layout.nb_channels = avio_rl32(s->pb);
st->codecpar->sample_rate = avio_rl32(s->pb);
if (st->codecpar->sample_rate <= 0)
return AVERROR_INVALIDDATA;
codec = avio_rl32(s->pb);
align = avio_rl32(s->pb);
avio_skip(s->pb, 4);
st->duration = avio_rl32(s->pb);
mult = avio_rl32(s->pb);
if (st->codecpar->ch_layout.nb_channels <= 0 || mult <= 0 ||
mult > INT_MAX / st->codecpar->ch_layout.nb_channels) {
av_log(s, AV_LOG_ERROR, "invalid number of channels %d x %d\n",
st->codecpar->ch_layout.nb_channels, mult);
return AVERROR_INVALIDDATA;
}
st->codecpar->ch_layout.nb_channels *= mult;
if (!align || align > INT_MAX / st->codecpar->ch_layout.nb_channels)
return AVERROR_INVALIDDATA;
st->codecpar->block_align = align * st->codecpar->ch_layout.nb_channels;
switch (codec) {
case 4: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA; break;
case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
default: avpriv_request_sample(s, "codec %X", codec);
return AVERROR_PATCHWELCOME;
}
avio_skip(s->pb, 0x800 - avio_tell(s->pb));
avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
return 0;
}
static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecParameters *par = s->streams[0]->codecpar;
return av_get_packet(s->pb, pkt, par->block_align);
}
const FFInputFormat ff_dcstr_demuxer = {
.p.name = "dcstr",
.p.long_name = NULL_IF_CONFIG_SMALL("Sega DC STR"),
.p.extensions = "str",
.p.flags = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_NOBINSEARCH,
.read_probe = dcstr_probe,
.read_header = dcstr_read_header,
.read_packet = dcstr_read_packet,
};