ffmpeg/libavformat/aiffenc.c

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/*
* AIFF/AIFF-C muxer
* Copyright (c) 2006 Patrick Guimond
*
* 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 "avformat.h"
#include "aiff.h"
#include "avio_internal.h"
typedef struct {
int64_t form;
int64_t frames;
int64_t ssnd;
} AIFFOutputContext;
static int aiff_write_header(AVFormatContext *s)
{
AIFFOutputContext *aiff = s->priv_data;
AVIOContext *pb = s->pb;
AVCodecContext *enc = s->streams[0]->codec;
AVExtFloat sample_rate;
int aifc = 0;
/* First verify if format is ok */
if (!enc->codec_tag)
return -1;
if (enc->codec_tag != MKTAG('N','O','N','E'))
aifc = 1;
/* FORM AIFF header */
ffio_wfourcc(pb, "FORM");
aiff->form = avio_tell(pb);
avio_wb32(pb, 0); /* file length */
ffio_wfourcc(pb, aifc ? "AIFC" : "AIFF");
if (aifc) { // compressed audio
enc->bits_per_coded_sample = 16;
if (!enc->block_align) {
av_log(s, AV_LOG_ERROR, "block align not set\n");
return -1;
}
/* Version chunk */
ffio_wfourcc(pb, "FVER");
avio_wb32(pb, 4);
avio_wb32(pb, 0xA2805140);
}
/* Common chunk */
ffio_wfourcc(pb, "COMM");
avio_wb32(pb, aifc ? 24 : 18); /* size */
avio_wb16(pb, enc->channels); /* Number of channels */
aiff->frames = avio_tell(pb);
avio_wb32(pb, 0); /* Number of frames */
if (!enc->bits_per_coded_sample)
enc->bits_per_coded_sample = av_get_bits_per_sample(enc->codec_id);
if (!enc->bits_per_coded_sample) {
av_log(s, AV_LOG_ERROR, "could not compute bits per sample\n");
return -1;
}
if (!enc->block_align)
enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
avio_wb16(pb, enc->bits_per_coded_sample); /* Sample size */
sample_rate = av_dbl2ext((double)enc->sample_rate);
avio_write(pb, (uint8_t*)&sample_rate, sizeof(sample_rate));
if (aifc) {
avio_wl32(pb, enc->codec_tag);
avio_wb16(pb, 0);
}
/* Sound data chunk */
ffio_wfourcc(pb, "SSND");
aiff->ssnd = avio_tell(pb); /* Sound chunk size */
avio_wb32(pb, 0); /* Sound samples data size */
avio_wb32(pb, 0); /* Data offset */
avio_wb32(pb, 0); /* Block-size (block align) */
av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);
/* Data is starting here */
avio_flush(pb);
return 0;
}
static int aiff_write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
avio_write(pb, pkt->data, pkt->size);
return 0;
}
static int aiff_write_trailer(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
AIFFOutputContext *aiff = s->priv_data;
AVCodecContext *enc = s->streams[0]->codec;
/* Chunks sizes must be even */
int64_t file_size, end_size;
end_size = file_size = avio_tell(pb);
if (file_size & 1) {
avio_w8(pb, 0);
end_size++;
}
if (s->pb->seekable) {
/* File length */
avio_seek(pb, aiff->form, SEEK_SET);
avio_wb32(pb, file_size - aiff->form - 4);
/* Number of sample frames */
avio_seek(pb, aiff->frames, SEEK_SET);
avio_wb32(pb, (file_size-aiff->ssnd-12)/enc->block_align);
/* Sound Data chunk size */
avio_seek(pb, aiff->ssnd, SEEK_SET);
avio_wb32(pb, file_size - aiff->ssnd - 4);
/* return to the end */
avio_seek(pb, end_size, SEEK_SET);
avio_flush(pb);
}
return 0;
}
AVOutputFormat ff_aiff_muxer = {
"aiff",
NULL_IF_CONFIG_SMALL("Audio IFF"),
"audio/aiff",
"aif,aiff,afc,aifc",
sizeof(AIFFOutputContext),
CODEC_ID_PCM_S16BE,
CODEC_ID_NONE,
aiff_write_header,
aiff_write_packet,
aiff_write_trailer,
.codec_tag= (const AVCodecTag* const []){ff_codec_aiff_tags, 0},
};