ffmpeg/libavformat/au.c

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/*
* AU muxer and demuxer
* Copyright (c) 2001 Fabrice Bellard
*
* 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
*/
/*
* First version by Francois Revol revol@free.fr
*
* Reference documents:
* http://www.opengroup.org/public/pubs/external/auformat.html
* http://www.goice.co.jp/member/mo/formats/au.html
*/
#include "avformat.h"
#include "avio_internal.h"
#include "pcm.h"
#include "riff.h"
/* if we don't know the size in advance */
#define AU_UNKNOWN_SIZE ((uint32_t)(~0))
/* The ffmpeg codecs we support, and the IDs they have in the file */
static const AVCodecTag codec_au_tags[] = {
{ CODEC_ID_PCM_MULAW, 1 },
{ CODEC_ID_PCM_S8, 2 },
{ CODEC_ID_PCM_S16BE, 3 },
{ CODEC_ID_PCM_S24BE, 4 },
{ CODEC_ID_PCM_S32BE, 5 },
{ CODEC_ID_PCM_F32BE, 6 },
{ CODEC_ID_PCM_F64BE, 7 },
{ CODEC_ID_PCM_ALAW, 27 },
{ CODEC_ID_NONE, 0 },
};
#if CONFIG_AU_MUXER
/* AUDIO_FILE header */
static int put_au_header(AVIOContext *pb, AVCodecContext *enc)
{
if(!enc->codec_tag)
return -1;
ffio_wfourcc(pb, ".snd"); /* magic number */
avio_wb32(pb, 24); /* header size */
avio_wb32(pb, AU_UNKNOWN_SIZE); /* data size */
avio_wb32(pb, (uint32_t)enc->codec_tag); /* codec ID */
avio_wb32(pb, enc->sample_rate);
avio_wb32(pb, (uint32_t)enc->channels);
return 0;
}
static int au_write_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
s->priv_data = NULL;
/* format header */
if (put_au_header(pb, s->streams[0]->codec) < 0) {
return -1;
}
avio_flush(pb);
return 0;
}
static int au_write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
avio_write(pb, pkt->data, pkt->size);
return 0;
}
static int au_write_trailer(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
int64_t file_size;
if (s->pb->seekable) {
/* update file size */
file_size = avio_tell(pb);
avio_seek(pb, 8, SEEK_SET);
avio_wb32(pb, (uint32_t)(file_size - 24));
avio_seek(pb, file_size, SEEK_SET);
avio_flush(pb);
}
return 0;
}
#endif /* CONFIG_AU_MUXER */
static int au_probe(AVProbeData *p)
{
/* check file header */
if (p->buf[0] == '.' && p->buf[1] == 's' &&
p->buf[2] == 'n' && p->buf[3] == 'd')
return AVPROBE_SCORE_MAX;
else
return 0;
}
/* au input */
static int au_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
int size, bps, data_size = 0;
unsigned int tag;
AVIOContext *pb = s->pb;
unsigned int id, channels, rate;
enum CodecID codec;
AVStream *st;
/* check ".snd" header */
tag = avio_rl32(pb);
if (tag != MKTAG('.', 's', 'n', 'd'))
return -1;
size = avio_rb32(pb); /* header size */
data_size = avio_rb32(pb); /* data size in bytes */
if (data_size < 0 && data_size != AU_UNKNOWN_SIZE) {
av_log(s, AV_LOG_ERROR, "Invalid negative data size '%d' found\n", data_size);
return AVERROR_INVALIDDATA;
}
id = avio_rb32(pb);
rate = avio_rb32(pb);
channels = avio_rb32(pb);
codec = ff_codec_get_id(codec_au_tags, id);
if (!(bps = av_get_bits_per_sample(codec))) {
av_log_ask_for_sample(s, "could not determine bits per sample\n");
return AVERROR_INVALIDDATA;
}
if (size >= 24) {
/* skip unused data */
avio_skip(pb, size - 24);
}
/* now we are ready: build format streams */
st = av_new_stream(s, 0);
if (!st)
return -1;
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_tag = id;
st->codec->codec_id = codec;
st->codec->channels = channels;
st->codec->sample_rate = rate;
if (data_size != AU_UNKNOWN_SIZE)
st->duration = (((int64_t)data_size)<<3) / (st->codec->channels * bps);
av_set_pts_info(st, 64, 1, rate);
return 0;
}
#define BLOCK_SIZE 1024
static int au_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
int ret;
ret= av_get_packet(s->pb, pkt, BLOCK_SIZE *
s->streams[0]->codec->channels *
av_get_bits_per_sample(s->streams[0]->codec->codec_id) >> 3);
if (ret < 0)
return ret;
pkt->stream_index = 0;
/* note: we need to modify the packet size here to handle the last
packet */
pkt->size = ret;
return 0;
}
#if CONFIG_AU_DEMUXER
AVInputFormat ff_au_demuxer = {
.name = "au",
.long_name = NULL_IF_CONFIG_SMALL("SUN AU format"),
.read_probe = au_probe,
.read_header = au_read_header,
.read_packet = au_read_packet,
.read_seek = pcm_read_seek,
.codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
};
#endif
#if CONFIG_AU_MUXER
AVOutputFormat ff_au_muxer = {
.name = "au",
.long_name = NULL_IF_CONFIG_SMALL("SUN AU format"),
.mime_type = "audio/basic",
.extensions = "au",
.audio_codec = CODEC_ID_PCM_S16BE,
.video_codec = CODEC_ID_NONE,
.write_header = au_write_header,
.write_packet = au_write_packet,
.write_trailer = au_write_trailer,
.codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},
};
#endif //CONFIG_AU_MUXER