PeerStreamer

/*

 * 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 "libavcodec/flac.h"

#include "avformat.h"

#include "flacenc.h"

#include "metadata.h"

#include "vorbiscomment.h"

#include "libavcodec/bytestream.h"

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);

    while (n_padding_bytes > 0) {

        avio_w8(pb, 0);

        n_padding_bytes--;

    }

    return 0;

}

static int flac_write_block_comment(AVIOContext *pb, AVMetadata **m,

                                    int last_block, int bitexact)

{

    const char *vendor = bitexact ? "ffmpeg" : LIBAVFORMAT_IDENT;

    unsigned int len, count;

    uint8_t *p, *p0;

    ff_metadata_conv(m, ff_vorbiscomment_metadata_conv, NULL);

    len = ff_vorbiscomment_length(*m, vendor, &count);

    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, count);

    avio_write(pb, p0, len+4);

    av_freep(&p0);

    p = NULL;

    return 0;

}

static int flac_write_header(struct AVFormatContext *s)

{

    int ret;

    AVCodecContext *codec = s->streams[0]->codec;

    ret = ff_flac_write_header(s->pb, codec, 0);

    if (ret)

        return ret;

    ret = flac_write_block_comment(s->pb, &s->metadata, 0,

                                   codec->flags & CODEC_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 let's try the flac default of 8192 bytes */

    flac_write_block_padding(s->pb, 8192, 1);

    return ret;

}

static int flac_write_trailer(struct AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    uint8_t *streaminfo;

    enum FLACExtradataFormat format;

    int64_t file_size;

    if (!ff_flac_is_extradata_valid(s->streams[0]->codec, &format, &streaminfo))

        return -1;

    if (!url_is_streamed(pb)) {

        /* 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);

        put_flush_packet(pb);

    } else {

        av_log(s, AV_LOG_WARNING, "unable to rewrite FLAC header.\n");

    }

    return 0;

}

static int flac_write_packet(struct AVFormatContext *s, AVPacket *pkt)

{

    avio_write(s->pb, pkt->data, pkt->size);

    put_flush_packet(s->pb);

    return 0;

}

AVOutputFormat ff_flac_muxer = {

    "flac",

    NULL_IF_CONFIG_SMALL("raw FLAC"),

    "audio/x-flac",

    "flac",

    0,

    CODEC_ID_FLAC,

    CODEC_ID_NONE,

    flac_write_header,

    flac_write_packet,

    flac_write_trailer,

    .flags= AVFMT_NOTIMESTAMPS,

};