PeerStreamer

/*

 * TTA demuxer

 * Copyright (c) 2006 Alex Beregszaszi

 *

 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include "avformat.h"

#include "bitstream.h"

typedef struct {

    int totalframes, currentframe;

} TTAContext;

static int tta_probe(AVProbeData *p)

{

    const uint8_t *d = p->buf;

    if (d[0] == 'T' && d[1] == 'T' && d[2] == 'A' && d[3] == '1')

        return 80;

    return 0;

}

static int tta_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    TTAContext *c = s->priv_data;

    AVStream *st;

    int i, channels, bps, samplerate, datalen, framelen;

    uint64_t framepos;

    if (get_le32(&s->pb) != ff_get_fourcc("TTA1"))

        return -1; // not tta file

    url_fskip(&s->pb, 2); // FIXME: flags

    channels = get_le16(&s->pb);

    bps = get_le16(&s->pb);

    samplerate = get_le32(&s->pb);

    if(samplerate <= 0 || samplerate > 1000000){

        av_log(s, AV_LOG_ERROR, "nonsense samplerate\n");

        return -1;

    }

    datalen = get_le32(&s->pb);

    if(datalen < 0){

        av_log(s, AV_LOG_ERROR, "nonsense datalen\n");

        return -1;

    }

    url_fskip(&s->pb, 4); // header crc

    framelen = samplerate*256/245;

    c->totalframes = datalen / framelen + ((datalen % framelen) ? 1 : 0);

    c->currentframe = 0;

    if(c->totalframes >= UINT_MAX/sizeof(uint32_t)){

        av_log(s, AV_LOG_ERROR, "totalframes too large\n");

        return -1;

    }

    st = av_new_stream(s, 0);

    if (!st)

        return AVERROR_NOMEM;

    av_set_pts_info(st, 64, 1, samplerate);

    st->start_time = 0;

    st->duration = datalen;

    framepos = url_ftell(&s->pb) + 4*c->totalframes + 4;

    for (i = 0; i < c->totalframes; i++) {

        uint32_t size = get_le32(&s->pb);

        av_add_index_entry(st, framepos, i*framelen, size, 0, AVINDEX_KEYFRAME);

        framepos += size;

    }

    url_fskip(&s->pb, 4); // seektable crc

    st->codec->codec_type = CODEC_TYPE_AUDIO;

    st->codec->codec_id = CODEC_ID_TTA;

    st->codec->channels = channels;

    st->codec->sample_rate = samplerate;

    st->codec->bits_per_sample = bps;

    st->codec->extradata_size = url_ftell(&s->pb);

    if(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE <= (unsigned)st->codec->extradata_size){

        //this check is redundant as get_buffer should fail

        av_log(s, AV_LOG_ERROR, "extradata_size too large\n");

        return -1;

    }

    st->codec->extradata = av_mallocz(st->codec->extradata_size+FF_INPUT_BUFFER_PADDING_SIZE);

    url_fseek(&s->pb, 0, SEEK_SET);

    get_buffer(&s->pb, st->codec->extradata, st->codec->extradata_size);

    return 0;

}

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

{

    TTAContext *c = s->priv_data;

    AVStream *st = s->streams[0];

    int size;

    // FIXME!

    if (c->currentframe > c->totalframes)

        return -1;

    size = st->index_entries[c->currentframe++].size;

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

}

AVInputFormat tta_demuxer = {

    "tta",

    "true-audio",

    sizeof(TTAContext),

    tta_probe,

    tta_read_header,

    tta_read_packet,

    NULL,

    .extensions = "tta",

};