FFmpeg/libavformat/hcom.c
Andreas Rheinhardt b800327f4c avformat/avformat: Add FFInputFormat, hide internals of AVInputFormat
This commit does for AVInputFormat what commit
59c9dc82f4 did for AVOutputFormat:
It adds a new type FFInputFormat, moves all the internals
of AVInputFormat to it and adds a now reduced AVInputFormat
as first member.

This does not affect/improve extensibility of both public
or private fields for demuxers (it is still a mess due to lavd).

This is possible since 50f34172e0
(which removed the last usage of an internal field of AVInputFormat
in fftools).

(Hint: tools/probetest.c accesses the internals of FFInputFormat
as well, but given that it is a testing tool this is not considered
a problem.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2024-03-07 08:53:31 -03:00

92 lines
2.8 KiB
C

/*
* HCOM demuxer
* Copyright (c) 2019 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 "demux.h"
#include "internal.h"
#include "pcm.h"
static int hcom_probe(const AVProbeData *p)
{
if (p->buf_size < 132)
return 0;
if (!memcmp(p->buf+65, "FSSD", 4) &&
!memcmp(p->buf+128, "HCOM", 4))
return AVPROBE_SCORE_MAX;
return 0;
}
static int hcom_read_header(AVFormatContext *s)
{
AVStream *st;
av_unused unsigned data_size, rsrc_size, huffcount;
unsigned compresstype, divisor;
unsigned dict_entries;
int ret;
avio_skip(s->pb, 83);
data_size = avio_rb32(s->pb);
rsrc_size = avio_rb32(s->pb);
avio_skip(s->pb, 128-91+4);
huffcount = avio_rb32(s->pb);
avio_skip(s->pb, 4);
compresstype = avio_rb32(s->pb);
if (compresstype > 1)
return AVERROR_INVALIDDATA;
divisor = avio_rb32(s->pb);
if (divisor == 0 || divisor > 4)
return AVERROR_INVALIDDATA;
dict_entries = avio_rb16(s->pb);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->ch_layout.nb_channels = 1;
st->codecpar->sample_rate = 22050 / divisor;
st->codecpar->codec_id = AV_CODEC_ID_HCOM;
st->codecpar->bits_per_coded_sample = 8;
st->codecpar->block_align = 4;
ret = ff_alloc_extradata(st->codecpar, dict_entries * 4 + 7);
if (ret < 0)
return ret;
AV_WB16(st->codecpar->extradata, dict_entries);
AV_WB32(st->codecpar->extradata + 2, compresstype);
avio_read(s->pb, st->codecpar->extradata + 6, dict_entries * 4);
avio_skip(s->pb, 1);
st->codecpar->extradata[dict_entries * 4 + 6] = avio_r8(s->pb);
avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
return 0;
}
const FFInputFormat ff_hcom_demuxer = {
.p.name = "hcom",
.p.long_name = NULL_IF_CONFIG_SMALL("Macintosh HCOM"),
.read_probe = hcom_probe,
.read_header = hcom_read_header,
.read_packet = ff_pcm_read_packet,
};