PeerStreamer

/*

 * 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;

    }

    put_flush_packet(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 (!url_is_streamed(s->pb)) {

        /* update file size */

        file_size = url_ftell(pb);

        url_fseek(pb, 8, SEEK_SET);

        avio_wb32(pb, (uint32_t)(file_size - 24));

        url_fseek(pb, file_size, SEEK_SET);

        put_flush_packet(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;

    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 */

    avio_rb32(pb); /* data size */

    id = avio_rb32(pb);

    rate = avio_rb32(pb);

    channels = avio_rb32(pb);

    codec = ff_codec_get_id(codec_au_tags, id);

    if (!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 */

        url_fseek(pb, size - 24, SEEK_CUR);

    }

    /* 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;

    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 = {

    "au",

    NULL_IF_CONFIG_SMALL("SUN AU format"),

    0,

    au_probe,

    au_read_header,

    au_read_packet,

    NULL,

    pcm_read_seek,

    .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},

};

#endif

#if CONFIG_AU_MUXER

AVOutputFormat ff_au_muxer = {

    "au",

    NULL_IF_CONFIG_SMALL("SUN AU format"),

    "audio/basic",

    "au",

    0,

    CODEC_ID_PCM_S16BE,

    CODEC_ID_NONE,

    au_write_header,

    au_write_packet,

    au_write_trailer,

    .codec_tag= (const AVCodecTag* const []){codec_au_tags, 0},

};

#endif //CONFIG_AU_MUXER