PeerStreamer

/*

 * WAV muxer and demuxer

 * Copyright (c) 2001, 2002 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

 */

#include "avformat.h"

#include "allformats.h"

#include "riff.h"

typedef struct {

    offset_t data;

    offset_t data_end;

} WAVContext;

#ifdef CONFIG_MUXERS

static int wav_write_header(AVFormatContext *s)

{

    WAVContext *wav = s->priv_data;

    ByteIOContext *pb = &s->pb;

    offset_t fmt;

    put_tag(pb, "RIFF");

    put_le32(pb, 0); /* file length */

    put_tag(pb, "WAVE");

    /* format header */

    fmt = start_tag(pb, "fmt ");

    if (put_wav_header(pb, s->streams[0]->codec) < 0) {

        av_free(wav);

        return -1;

    }

    end_tag(pb, fmt);

    av_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codec->sample_rate);

    /* data header */

    wav->data = start_tag(pb, "data");

    put_flush_packet(pb);

    return 0;

}

static int wav_write_packet(AVFormatContext *s, AVPacket *pkt)

{

    ByteIOContext *pb = &s->pb;

    put_buffer(pb, pkt->data, pkt->size);

    return 0;

}

static int wav_write_trailer(AVFormatContext *s)

{

    ByteIOContext *pb = &s->pb;

    WAVContext *wav = s->priv_data;

    offset_t file_size;

    if (!url_is_streamed(&s->pb)) {

        end_tag(pb, wav->data);

        /* update file size */

        file_size = url_ftell(pb);

        url_fseek(pb, 4, SEEK_SET);

        put_le32(pb, (uint32_t)(file_size - 8));

        url_fseek(pb, file_size, SEEK_SET);

        put_flush_packet(pb);

    }

    return 0;

}

#endif //CONFIG_MUXERS

/* return the size of the found tag */

/* XXX: > 2GB ? */

static int find_tag(ByteIOContext *pb, uint32_t tag1)

{

    unsigned int tag;

    int size;

    for(;;) {

        if (url_feof(pb))

            return -1;

        tag = get_le32(pb);

        size = get_le32(pb);

        if (tag == tag1)

            break;

        url_fseek(pb, size, SEEK_CUR);

    }

    if (size < 0)

        size = 0x7fffffff;

    return size;

}

static int wav_probe(AVProbeData *p)

{

    /* check file header */

    if (p->buf_size <= 32)

        return 0;

    if (p->buf[0] == 'R' && p->buf[1] == 'I' &&

        p->buf[2] == 'F' && p->buf[3] == 'F' &&

        p->buf[8] == 'W' && p->buf[9] == 'A' &&

        p->buf[10] == 'V' && p->buf[11] == 'E')

        return AVPROBE_SCORE_MAX;

    else

        return 0;

}

/* wav input */

static int wav_read_header(AVFormatContext *s,

                           AVFormatParameters *ap)

{

    int size;

    unsigned int tag;

    ByteIOContext *pb = &s->pb;

    AVStream *st;

    WAVContext *wav = s->priv_data;

    /* check RIFF header */

    tag = get_le32(pb);

    if (tag != MKTAG('R', 'I', 'F', 'F'))

        return -1;

    get_le32(pb); /* file size */

    tag = get_le32(pb);

    if (tag != MKTAG('W', 'A', 'V', 'E'))

        return -1;

    /* parse fmt header */

    size = find_tag(pb, MKTAG('f', 'm', 't', ' '));

    if (size < 0)

        return -1;

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR_NOMEM;

    get_wav_header(pb, st->codec, size);

    st->need_parsing = 1;

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

    size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));

    if (size < 0)

        return -1;

    wav->data_end= url_ftell(pb) + size;

    return 0;

}

#define MAX_SIZE 4096

static int wav_read_packet(AVFormatContext *s,

                           AVPacket *pkt)

{

    int ret, size, left;

    AVStream *st;

    WAVContext *wav = s->priv_data;

    if (url_feof(&s->pb))

        return AVERROR_IO;

    st = s->streams[0];

    left= wav->data_end - url_ftell(&s->pb);

    if(left <= 0){

        left = find_tag(&(s->pb), MKTAG('d', 'a', 't', 'a'));

        if (left < 0) {

            return AVERROR_IO;

        }

        wav->data_end= url_ftell(&s->pb) + left;

    }

    size = MAX_SIZE;

    if (st->codec->block_align > 1) {

        if (size < st->codec->block_align)

            size = st->codec->block_align;

        size = (size / st->codec->block_align) * st->codec->block_align;

    }

    size= FFMIN(size, left);

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

    if (ret <= 0)

        return AVERROR_IO;

    pkt->stream_index = 0;

    /* note: we need to modify the packet size here to handle the last

       packet */

    pkt->size = ret;

    return ret;

}

static int wav_read_close(AVFormatContext *s)

{

    return 0;

}

static int wav_read_seek(AVFormatContext *s,

                         int stream_index, int64_t timestamp, int flags)

{

    AVStream *st;

    st = s->streams[0];

    switch(st->codec->codec_id) {

    case CODEC_ID_MP2:

    case CODEC_ID_MP3:

    case CODEC_ID_AC3:

    case CODEC_ID_DTS:

        /* use generic seeking with dynamically generated indexes */

        return -1;

    default:

        break;

    }

    return pcm_read_seek(s, stream_index, timestamp, flags);

}

#ifdef CONFIG_WAV_DEMUXER

AVInputFormat wav_demuxer = {

    "wav",

    "wav format",

    sizeof(WAVContext),

    wav_probe,

    wav_read_header,

    wav_read_packet,

    wav_read_close,

    wav_read_seek,

    .flags= AVFMT_GENERIC_INDEX,

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

};

#endif

#ifdef CONFIG_WAV_MUXER

AVOutputFormat wav_muxer = {

    "wav",

    "wav format",

    "audio/x-wav",

    "wav",

    sizeof(WAVContext),

    CODEC_ID_PCM_S16LE,

    CODEC_ID_NONE,

    wav_write_header,

    wav_write_packet,

    wav_write_trailer,

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

};

#endif