/*
* raw FLAC muxer
* Copyright (c) 2006-2009 Justin Ruggles
*
* 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/channel_layout.h"
#include "libavutil/opt.h"
#include "libavcodec/flac.h"
#include "avformat.h"
#include "avio_internal.h"
#include "flacenc.h"
#include "vorbiscomment.h"
#include "libavcodec/bytestream.h"
typedef struct FlacMuxerContext {
const AVClass *class;
int write_header;
/* updated streaminfo sent by the encoder at the end */
uint8_t *streaminfo;
} FlacMuxerContext;
static int flac_write_block_padding(AVIOContext *pb, unsigned int n_padding_bytes,
int last_block)
{
avio_w8(pb, last_block ? 0x81 : 0x01);
avio_wb24(pb, n_padding_bytes);
ffio_fill(pb, 0, n_padding_bytes);
return 0;
}
static int flac_write_block_comment(AVIOContext *pb, AVDictionary **m,
int last_block, int bitexact)
{
const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;
int64_t len;
uint8_t *p, *p0;
ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL);
len = ff_vorbiscomment_length(*m, vendor);
if (len >= ((1<<24) - 4))
return AVERROR(EINVAL);
p0 = av_malloc(len+4);
if (!p0)
return AVERROR(ENOMEM);
p = p0;
bytestream_put_byte(&p, last_block ? 0x84 : 0x04);
bytestream_put_be24(&p, len);
ff_vorbiscomment_write(&p, m, vendor);
avio_write(pb, p0, len+4);
av_freep(&p0);
p = NULL;
return 0;
}
static int flac_write_header(struct AVFormatContext *s)
{
int ret;
int padding = s->metadata_header_padding;
AVCodecContext *codec = s->streams[0]->codec;
FlacMuxerContext *c = s->priv_data;
if (!c->write_header)
return 0;
if (s->nb_streams > 1) {
av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
return AVERROR(EINVAL);
}
if (codec->codec_id != AV_CODEC_ID_FLAC) {
av_log(s, AV_LOG_ERROR, "unsupported codec\n");
return AVERROR(EINVAL);
}
if (padding < 0)
padding = 8192;
/* The FLAC specification states that 24 bits are used to represent the
* size of a metadata block so we must clip this value to 2^24-1. */
padding = av_clip_uintp2(padding, 24);
ret = ff_flac_write_header(s->pb, codec->extradata,
codec->extradata_size, 0);
if (ret)
return ret;
/* add the channel layout tag */
if (codec->channel_layout &&
!(codec->channel_layout & ~0x3ffffULL) &&
!ff_flac_is_native_layout(codec->channel_layout)) {
AVDictionaryEntry *chmask = av_dict_get(s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK",
NULL, 0);
if (chmask) {
av_log(s, AV_LOG_WARNING, "A WAVEFORMATEXTENSIBLE_CHANNEL_MASK is "
"already present, this muxer will not overwrite it.\n");
} else {
uint8_t buf[32];
snprintf(buf
, sizeof(buf
), "0x%"PRIx64
, codec
->channel_layout
); av_dict_set(&s->metadata, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0);
}
}
ret = flac_write_block_comment(s->pb, &s->metadata, !padding,
s->flags & AVFMT_FLAG_BITEXACT);
if (ret)
return ret;
/* The command line flac encoder defaults to placing a seekpoint
* every 10s. So one might add padding to allow that later
* but there seems to be no simple way to get the duration here.
* So just add the amount requested by the user. */
if (padding)
flac_write_block_padding(s->pb, padding, 1);
return ret;
}
static int flac_write_trailer(struct AVFormatContext *s)
{
AVIOContext *pb = s->pb;
int64_t file_size;
FlacMuxerContext *c = s->priv_data;
uint8_t *streaminfo = c->streaminfo ? c->streaminfo :
s->streams[0]->codec->extradata;
if (!c->write_header || !streaminfo)
return 0;
if (pb->seekable) {
/* rewrite the STREAMINFO header block data */
file_size = avio_tell(pb);
avio_seek(pb, 8, SEEK_SET);
avio_write(pb, streaminfo, FLAC_STREAMINFO_SIZE);
avio_seek(pb, file_size, SEEK_SET);
avio_flush(pb);
} else {
av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");
}
av_freep(&c->streaminfo);
return 0;
}
static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
FlacMuxerContext *c = s->priv_data;
uint8_t *streaminfo;
int streaminfo_size;
/* check for updated streaminfo */
streaminfo = av_packet_get_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA,
&streaminfo_size);
if (streaminfo && streaminfo_size == FLAC_STREAMINFO_SIZE) {
av_freep(&c->streaminfo);
c->streaminfo = av_malloc(FLAC_STREAMINFO_SIZE);
if (!c->streaminfo)
return AVERROR(ENOMEM);
memcpy(c
->streaminfo
, streaminfo
, FLAC_STREAMINFO_SIZE
); }
if (pkt->size)
avio_write(s->pb, pkt->data, pkt->size);
return 0;
}
static const AVOption flacenc_options[] = {
{ "write_header", "Write the file header", offsetof(FlacMuxerContext
, write_header
), AV_OPT_TYPE_INT
, {.
i64 = 1}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM
}, { NULL },
};
static const AVClass flac_muxer_class = {
.class_name = "flac muxer",
.item_name = av_default_item_name,
.option = flacenc_options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_flac_muxer = {
.name = "flac",
.long_name = NULL_IF_CONFIG_SMALL("raw FLAC"),
.priv_data_size = sizeof(FlacMuxerContext),
.mime_type = "audio/x-flac",
.extensions = "flac",
.audio_codec = AV_CODEC_ID_FLAC,
.video_codec = AV_CODEC_ID_NONE,
.write_header = flac_write_header,
.write_packet = flac_write_packet,
.write_trailer = flac_write_trailer,
.flags = AVFMT_NOTIMESTAMPS,
.priv_class = &flac_muxer_class,
};