mirror of https://git.ffmpeg.org/ffmpeg.git
103 lines
2.9 KiB
C
103 lines
2.9 KiB
C
|
/*
|
||
|
|
* Raw AC-4 muxer
|
||
|
|
*
|
||
|
|
* 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 "libavcodec/codec_id.h"
|
||
|
|
#include "libavcodec/codec_par.h"
|
||
|
|
#include "libavcodec/packet.h"
|
||
|
|
#include "libavutil/crc.h"
|
||
|
|
#include "libavutil/opt.h"
|
||
|
|
#include "avformat.h"
|
||
|
|
#include "mux.h"
|
||
|
|
|
||
|
|
typedef struct AC4Context {
|
||
|
|
AVClass *class;
|
||
|
|
int write_crc;
|
||
|
|
} AC4Context;
|
||
|
|
|
||
|
|
static int ac4_init(AVFormatContext *s)
|
||
|
|
{
|
||
|
|
AVCodecParameters *par = s->streams[0]->codecpar;
|
||
|
|
|
||
|
|
if (s->nb_streams != 1 || par->codec_id != AV_CODEC_ID_AC4) {
|
||
|
|
av_log(s, AV_LOG_ERROR, "Only one AC-4 stream can be muxed by the AC-4 muxer\n");
|
||
|
|
return AVERROR(EINVAL);
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int ac4_write_packet(AVFormatContext *s, AVPacket *pkt)
|
||
|
|
{
|
||
|
|
AC4Context *ac4 = s->priv_data;
|
||
|
|
AVIOContext *pb = s->pb;
|
||
|
|
|
||
|
|
if (!pkt->size)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
if (ac4->write_crc)
|
||
|
|
avio_wb16(pb, 0xAC41);
|
||
|
|
else
|
||
|
|
avio_wb16(pb, 0xAC40);
|
||
|
|
|
||
|
|
if (pkt->size >= 0xffff) {
|
||
|
|
avio_wb16(pb, 0xffff);
|
||
|
|
avio_wb24(pb, pkt->size);
|
||
|
|
} else {
|
||
|
|
avio_wb16(pb, pkt->size);
|
||
|
|
}
|
||
|
|
|
||
|
|
avio_write(pb, pkt->data, pkt->size);
|
||
|
|
|
||
|
|
if (ac4->write_crc) {
|
||
|
|
uint16_t crc = av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, pkt->data, pkt->size);
|
||
|
|
avio_wl16(pb, crc);
|
||
|
|
}
|
||
|
|
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
#define ENC AV_OPT_FLAG_ENCODING_PARAM
|
||
|
|
#define OFFSET(obj) offsetof(AC4Context, obj)
|
||
|
|
static const AVOption ac4_options[] = {
|
||
|
|
{ "write_crc", "enable checksum", OFFSET(write_crc), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, ENC},
|
||
|
|
{ NULL },
|
||
|
|
};
|
||
|
|
|
||
|
|
static const AVClass ac4_muxer_class = {
|
||
|
|
.class_name = "AC4 muxer",
|
||
|
|
.item_name = av_default_item_name,
|
||
|
|
.option = ac4_options,
|
||
|
|
.version = LIBAVUTIL_VERSION_INT,
|
||
|
|
};
|
||
|
|
|
||
|
|
const FFOutputFormat ff_ac4_muxer = {
|
||
|
|
.p.name = "ac4",
|
||
|
|
.p.long_name = NULL_IF_CONFIG_SMALL("raw AC-4"),
|
||
|
|
.p.mime_type = "audio/ac4",
|
||
|
|
.p.extensions = "ac4",
|
||
|
|
.priv_data_size = sizeof(AC4Context),
|
||
|
|
.p.audio_codec = AV_CODEC_ID_AC4,
|
||
|
|
.p.video_codec = AV_CODEC_ID_NONE,
|
||
|
|
.init = ac4_init,
|
||
|
|
.write_packet = ac4_write_packet,
|
||
|
|
.p.priv_class = &ac4_muxer_class,
|
||
|
|
.p.flags = AVFMT_NOTIMESTAMPS,
|
||
|
|
};
|