ffmpeg/libavformat/mlpdec.c

130 lines
3.8 KiB
C

/*
* MLP and TrueHD demuxer
* Copyright (c) 2001 Fabrice Bellard
* Copyright (c) 2005 Alex Beregszaszi
* Copyright (c) 2015 Carl Eugen Hoyos
*
* 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 "avio_internal.h"
#include "internal.h"
#include "rawdec.h"
#include "libavutil/intreadwrite.h"
#include "libavcodec/mlp.h"
#include "libavcodec/mlp_parse.h"
static int av_always_inline mlp_thd_probe(const AVProbeData *p, uint32_t sync)
{
const uint8_t *buf, *last_buf = p->buf, *end = p->buf + p->buf_size;
int frames = 0, valid = 0, size = 0;
int nsubframes = 0;
for (buf = p->buf; buf + 8 <= end; buf++) {
if (AV_RB32(buf + 4) == sync) {
frames++;
if (last_buf + size == buf) {
valid += 1 + nsubframes / 8;
}
nsubframes = 0;
last_buf = buf;
size = (AV_RB16(buf) & 0xfff) * 2;
} else if (buf - last_buf == size) {
nsubframes++;
size += (AV_RB16(buf) & 0xfff) * 2;
}
}
if (valid >= 100)
return AVPROBE_SCORE_MAX;
return 0;
}
static int mlp_read_header(AVFormatContext *s)
{
int ret = ff_raw_audio_read_header(s);
if (ret < 0)
return ret;
ret = ffio_ensure_seekback(s->pb, 10);
if (ret == 0) {
uint8_t buffer[10];
int read, sample_rate = 0;
read = avio_read(s->pb, buffer, 10);
if (read == 10) {
switch (buffer[7]) {
case SYNC_TRUEHD:
sample_rate = mlp_samplerate(buffer[8] >> 4);
break;
case SYNC_MLP:
sample_rate = mlp_samplerate(buffer[9] >> 4);
break;
}
if (sample_rate)
avpriv_set_pts_info(s->streams[0], 64, 1, sample_rate);
}
if (read > 0)
avio_seek(s->pb, -read, SEEK_CUR);
}
return 0;
}
#if CONFIG_MLP_DEMUXER
static int mlp_probe(const AVProbeData *p)
{
return mlp_thd_probe(p, 0xf8726fbb);
}
const AVInputFormat ff_mlp_demuxer = {
.name = "mlp",
.long_name = NULL_IF_CONFIG_SMALL("raw MLP"),
.read_probe = mlp_probe,
.read_header = mlp_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
.extensions = "mlp",
.raw_codec_id = AV_CODEC_ID_MLP,
.priv_data_size = sizeof(FFRawDemuxerContext),
.priv_class = &ff_raw_demuxer_class,
};
#endif
#if CONFIG_TRUEHD_DEMUXER
static int thd_probe(const AVProbeData *p)
{
return mlp_thd_probe(p, 0xf8726fba);
}
const AVInputFormat ff_truehd_demuxer = {
.name = "truehd",
.long_name = NULL_IF_CONFIG_SMALL("raw TrueHD"),
.read_probe = thd_probe,
.read_header = mlp_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
.extensions = "thd",
.raw_codec_id = AV_CODEC_ID_TRUEHD,
.priv_data_size = sizeof(FFRawDemuxerContext),
.priv_class = &ff_raw_demuxer_class,
};
#endif