PeerStreamer

/*

 * SoX native format demuxer

 * Copyright (c) 2009 Daniel Verkamp <daniel@drv.nu>

 *

 * Based on libSoX sox-fmt.c

 * Copyright (c) 2008 robs@users.sourceforge.net

 *

 * 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

 */

/**

 * SoX native format demuxer

 * @file

 * @author Daniel Verkamp

 * @sa http://wiki.multimedia.cx/index.php?title=SoX_native_intermediate_format

 */

#include "libavutil/intreadwrite.h"

#include "avformat.h"

#include "pcm.h"

#include "sox.h"

static int sox_probe(AVProbeData *p)

{

    if (AV_RL32(p->buf) == SOX_TAG || AV_RB32(p->buf) == SOX_TAG)

        return AVPROBE_SCORE_MAX;

    return 0;

}

static int sox_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

    AVIOContext *pb = s->pb;

    unsigned header_size, comment_size;

    double sample_rate, sample_rate_frac;

    AVStream *st;

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR(ENOMEM);

    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

    if (avio_rl32(pb) == SOX_TAG) {

        st->codec->codec_id = CODEC_ID_PCM_S32LE;

        header_size         = avio_rl32(pb);

        avio_seek(pb, 8, SEEK_CUR); /* sample count */

        sample_rate         = av_int2dbl(avio_rl64(pb));

        st->codec->channels = avio_rl32(pb);

        comment_size        = avio_rl32(pb);

    } else {

        st->codec->codec_id = CODEC_ID_PCM_S32BE;

        header_size         = avio_rb32(pb);

        avio_seek(pb, 8, SEEK_CUR); /* sample count */

        sample_rate         = av_int2dbl(avio_rb64(pb));

        st->codec->channels = avio_rb32(pb);

        comment_size        = avio_rb32(pb);

    }

    if (comment_size > 0xFFFFFFFFU - SOX_FIXED_HDR - 4U) {

        av_log(s, AV_LOG_ERROR, "invalid comment size (%u)\n", comment_size);

        return -1;

    }

    if (sample_rate <= 0 || sample_rate > INT_MAX) {

        av_log(s, AV_LOG_ERROR, "invalid sample rate (%f)\n", sample_rate);

        return -1;

    }

    sample_rate_frac = sample_rate - floor(sample_rate);

    if (sample_rate_frac)

        av_log(s, AV_LOG_WARNING,

               "truncating fractional part of sample rate (%f)\n",

               sample_rate_frac);

    if ((header_size + 4) & 7 || header_size < SOX_FIXED_HDR + comment_size

        || st->codec->channels > 65535) /* Reserve top 16 bits */ {

        av_log(s, AV_LOG_ERROR, "invalid header\n");

        return -1;

    }

    if (comment_size && comment_size < UINT_MAX) {

        char *comment = av_malloc(comment_size+1);

        if (avio_read(pb, comment, comment_size) != comment_size) {

            av_freep(&comment);

            return AVERROR(EIO);

        }

        comment[comment_size] = 0;

        av_metadata_set2(&s->metadata, "comment", comment,

                               AV_METADATA_DONT_STRDUP_VAL);

    }

    avio_seek(pb, header_size - SOX_FIXED_HDR - comment_size, SEEK_CUR);

    st->codec->sample_rate           = sample_rate;

    st->codec->bits_per_coded_sample = 32;

    st->codec->bit_rate              = st->codec->sample_rate *

                                       st->codec->bits_per_coded_sample *

                                       st->codec->channels;

    st->codec->block_align           = st->codec->bits_per_coded_sample *

                                       st->codec->channels / 8;

    av_set_pts_info(st, 64, 1, st->codec->sample_rate);

    return 0;

}

#define SOX_SAMPLES 1024

static int sox_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    int ret, size;

    if (s->pb->eof_reached)

        return AVERROR_EOF;

    size = SOX_SAMPLES*s->streams[0]->codec->block_align;

    ret = av_get_packet(s->pb, pkt, size);

    if (ret < 0)

        return AVERROR(EIO);

    pkt->stream_index = 0;

    pkt->size = ret;

    return 0;

}

AVInputFormat ff_sox_demuxer = {

    "sox",

    NULL_IF_CONFIG_SMALL("SoX native format"),

    0,

    sox_probe,

    sox_read_header,

    sox_read_packet,

    NULL,

    pcm_read_seek,

};