mirror of https://github.com/FFmpeg/FFmpeg.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
101 lines
2.8 KiB
101 lines
2.8 KiB
/* |
|
* 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", |
|
.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, |
|
};
|
|
|