mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-02 03:06:28 +02:00
b800327f4c
This commit does for AVInputFormat what commit59c9dc82f4did 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 since50f34172e0(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>
106 lines
2.6 KiB
C
106 lines
2.6 KiB
C
/*
|
|
* RAW AC-4 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/avassert.h"
|
|
#include "libavutil/crc.h"
|
|
#include "avformat.h"
|
|
#include "demux.h"
|
|
#include "rawdec.h"
|
|
|
|
static int ac4_probe(const AVProbeData *p)
|
|
{
|
|
const uint8_t *buf = p->buf;
|
|
int left = p->buf_size;
|
|
int max_frames = 0;
|
|
|
|
while (left > 7) {
|
|
int size;
|
|
|
|
if (buf[0] == 0xAC &&
|
|
(buf[1] == 0x40 ||
|
|
buf[1] == 0x41)) {
|
|
size = (buf[2] << 8) | buf[3];
|
|
if (size == 0xFFFF)
|
|
size = 3 + ((buf[4] << 16) | (buf[5] << 8) | buf[6]);
|
|
size += 4;
|
|
if (buf[1] == 0x41)
|
|
size += 2;
|
|
max_frames++;
|
|
left -= size;
|
|
buf += size;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return FFMIN(AVPROBE_SCORE_MAX, max_frames * 7);
|
|
}
|
|
|
|
static int ac4_read_header(AVFormatContext *s)
|
|
{
|
|
AVStream *st;
|
|
|
|
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_AC4;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ac4_read_packet(AVFormatContext *s, AVPacket *pkt)
|
|
{
|
|
AVIOContext *pb = s->pb;
|
|
int64_t pos;
|
|
uint16_t sync;
|
|
int ret, size;
|
|
|
|
if (avio_feof(s->pb))
|
|
return AVERROR_EOF;
|
|
|
|
pos = avio_tell(s->pb);
|
|
sync = avio_rb16(pb);
|
|
size = avio_rb16(pb);
|
|
if (size == 0xffff)
|
|
size = avio_rb24(pb);
|
|
|
|
ret = av_get_packet(pb, pkt, size);
|
|
pkt->pos = pos;
|
|
pkt->stream_index = 0;
|
|
|
|
if (sync == 0xAC41)
|
|
avio_skip(pb, 2);
|
|
|
|
return ret;
|
|
}
|
|
|
|
const FFInputFormat ff_ac4_demuxer = {
|
|
.p.name = "ac4",
|
|
.p.long_name = NULL_IF_CONFIG_SMALL("raw AC-4"),
|
|
.p.flags = AVFMT_GENERIC_INDEX,
|
|
.p.extensions = "ac4",
|
|
.read_probe = ac4_probe,
|
|
.read_header = ac4_read_header,
|
|
.read_packet = ac4_read_packet,
|
|
};
|