ffmpeg/libavformat/hca.c

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2020-03-15 12:55:15 +00:00
/*
* HCA demuxer
* Copyright (c) 2020 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 "libavcodec/bytestream.h"
#include "avformat.h"
#include "internal.h"
static int hca_probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) != MKTAG('H', 'C', 'A', 0))
return 0;
if (AV_RL32(p->buf + 8) != MKTAG('f', 'm', 't', 0))
return 0;
return AVPROBE_SCORE_MAX / 3;
}
static int hca_read_header(AVFormatContext *s)
{
AVCodecParameters *par;
GetByteContext gb;
AVIOContext *pb = s->pb;
AVStream *st;
uint32_t chunk;
uint16_t version;
uint32_t block_count;
uint16_t block_size;
int ret;
avio_skip(pb, 4);
version = avio_rb16(pb);
s->internal->data_offset = avio_rb16(pb);
if (s->internal->data_offset <= 8)
return AVERROR_INVALIDDATA;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
par = st->codecpar;
ret = ff_alloc_extradata(par, s->internal->data_offset);
if (ret < 0)
return ret;
ret = avio_read(pb, par->extradata + 8, par->extradata_size - 8);
if (ret < par->extradata_size - 8)
return AVERROR(EIO);
AV_WL32(par->extradata, MKTAG('H', 'C', 'A', 0));
AV_WB16(par->extradata + 4, version);
AV_WB16(par->extradata + 6, s->internal->data_offset);
bytestream2_init(&gb, par->extradata + 8, par->extradata_size - 8);
if (bytestream2_get_le32(&gb) != MKTAG('f', 'm', 't', 0))
return AVERROR_INVALIDDATA;
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_HCA;
par->codec_tag = 0;
par->channels = bytestream2_get_byte(&gb);
par->sample_rate = bytestream2_get_be24(&gb);
block_count = bytestream2_get_be32(&gb);
bytestream2_skip(&gb, 4);
chunk = bytestream2_get_le32(&gb);
if (chunk == MKTAG('c', 'o', 'm', 'p')) {
block_size = bytestream2_get_be16(&gb);
} else if (chunk == MKTAG('d', 'e', 'c', 0)) {
block_size = bytestream2_get_be16(&gb);
} else {
return AVERROR_INVALIDDATA;
}
if (block_size < 8)
return AVERROR_INVALIDDATA;
par->block_align = block_size;
st->duration = 1024 * block_count;
avio_seek(pb, s->internal->data_offset, SEEK_SET);
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
return 0;
}
static int hca_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecParameters *par = s->streams[0]->codecpar;
int ret;
ret = av_get_packet(s->pb, pkt, par->block_align);
pkt->duration = 1024;
return ret;
}
const AVInputFormat ff_hca_demuxer = {
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.name = "hca",
.long_name = NULL_IF_CONFIG_SMALL("CRI HCA"),
.read_probe = hca_probe,
.read_header = hca_read_header,
.read_packet = hca_read_packet,
.extensions = "hca",
.flags = AVFMT_GENERIC_INDEX,
};