ffmpeg/libavformat/aixdec.c

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/*
* AIX demuxer
* Copyright (c) 2016 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 "internal.h"
static int aix_probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||
AV_RB32(p->buf + 8) != 0x01000014 ||
AV_RB32(p->buf + 12) != 0x00000800)
return 0;
return AVPROBE_SCORE_MAX;
}
static int aix_read_header(AVFormatContext *s)
{
unsigned nb_streams, first_offset, nb_segments;
unsigned stream_list_offset;
unsigned segment_list_offset = 0x20;
unsigned segment_list_entry_size = 0x10;
unsigned size;
int i;
avio_skip(s->pb, 4);
first_offset = avio_rb32(s->pb) + 8;
avio_skip(s->pb, 16);
nb_segments = avio_rb16(s->pb);
if (nb_segments == 0)
return AVERROR_INVALIDDATA;
stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;
if (stream_list_offset >= first_offset)
return AVERROR_INVALIDDATA;
avio_seek(s->pb, stream_list_offset, SEEK_SET);
nb_streams = avio_r8(s->pb);
if (nb_streams == 0)
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 7);
for (i = 0; i < nb_streams; i++) {
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_ADPCM_ADX;
st->codecpar->sample_rate = avio_rb32(s->pb);
st->codecpar->ch_layout.nb_channels = avio_r8(s->pb);
avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
avio_skip(s->pb, 3);
}
avio_seek(s->pb, first_offset, SEEK_SET);
for (i = 0; i < nb_streams; i++) {
if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))
return AVERROR_INVALIDDATA;
size = avio_rb32(s->pb);
if (size <= 8)
return AVERROR_INVALIDDATA;
avio_skip(s->pb, 8);
ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);
}
return 0;
}
static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
{
unsigned size, index, duration, chunk;
int64_t pos;
int sequence, ret, i;
pos = avio_tell(s->pb);
if (avio_feof(s->pb))
return AVERROR_EOF;
chunk = avio_rl32(s->pb);
size = avio_rb32(s->pb);
if (chunk == MKTAG('A','I','X','E')) {
avio_skip(s->pb, size);
for (i = 0; i < s->nb_streams; i++) {
if (avio_feof(s->pb))
return AVERROR_EOF;
chunk = avio_rl32(s->pb);
size = avio_rb32(s->pb);
avio_skip(s->pb, size);
}
pos = avio_tell(s->pb);
chunk = avio_rl32(s->pb);
size = avio_rb32(s->pb);
}
if (chunk != MKTAG('A','I','X','P'))
return AVERROR_INVALIDDATA;
if (size <= 8)
return AVERROR_INVALIDDATA;
index = avio_r8(s->pb);
if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)
return AVERROR_INVALIDDATA;
duration = avio_rb16(s->pb);
sequence = avio_rb32(s->pb);
if (sequence < 0) {
avio_skip(s->pb, size - 8);
return 0;
}
ret = av_get_packet(s->pb, pkt, size - 8);
pkt->stream_index = index;
pkt->duration = duration;
pkt->pos = pos;
return ret;
}
const AVInputFormat ff_aix_demuxer = {
.name = "aix",
.long_name = NULL_IF_CONFIG_SMALL("CRI AIX"),
.read_probe = aix_probe,
.read_header = aix_read_header,
.read_packet = aix_read_packet,
.extensions = "aix",
.flags = AVFMT_GENERIC_INDEX,
};