av_log(NULL, AV_LOG_DEBUG, "\nCalculated information:\n\n");    av_log(NULL, AV_LOG_DEBUG, "junklength           = %d\n", ape_ctx->junklength);    av_log(NULL, AV_LOG_DEBUG, "firstframe           = %d\n", ape_ctx->firstframe);    av_log(NULL, AV_LOG_DEBUG, "totalsamples         = %d\n", ape_ctx->totalsamples);#endif}static int ape_read_header(AVFormatContext * s, AVFormatParameters * ap){    ByteIOContext *pb = s->pb;    APEContext *ape = s->priv_data;    AVStream *st;    uint32_t tag;    int i;    int total_blocks;    int64_t pts;    /* TODO: Skip any leading junk such as id3v2 tags */    ape->junklength = 0;    tag = get_le32(pb);    if (tag != MKTAG('M', 'A', 'C', ' '))        return -1;    ape->fileversion = get_le16(pb);    if (ape->fileversion < APE_MIN_VERSION || ape->fileversion > APE_MAX_VERSION) {        av_log(s, AV_LOG_ERROR, "Unsupported file version - %d.%02d\n", ape->fileversion / 1000, (ape->fileversion % 1000) / 10);        return -1;    }    if (ape->fileversion >= 3980) {        ape->padding1             = get_le16(pb);        ape->descriptorlength     = get_le32(pb);        ape->headerlength         = get_le32(pb);        ape->seektablelength      = get_le32(pb);        ape->wavheaderlength      = get_le32(pb);        ape->audiodatalength      = get_le32(pb);        ape->audiodatalength_high = get_le32(pb);        ape->wavtaillength        = get_le32(pb);        get_buffer(pb, ape->md5, 16);        /* Skip any unknown bytes at the end of the descriptor.           This is for future compatibility */        if (ape->descriptorlength > 52)            url_fseek(pb, ape->descriptorlength - 52, SEEK_CUR);        /* Read header data */        ape->compressiontype      = get_le16(pb);        ape->formatflags          = get_le16(pb);        ape->blocksperframe       = get_le32(pb);        ape->finalframeblocks     = get_le32(pb);        ape->totalframes          = get_le32(pb);        ape->bps                  = get_le16(pb);        ape->channels             = get_le16(pb);        ape->samplerate           = get_le32(pb);    } else {        ape->descriptorlength = 0;        ape->headerlength = 32;        ape->compressiontype      = get_le16(pb);        ape->formatflags          = get_le16(pb);        ape->channels             = get_le16(pb);        ape->samplerate           = get_le32(pb);        ape->wavheaderlength      = get_le32(pb);        ape->wavtaillength        = get_le32(pb);        ape->totalframes          = get_le32(pb);        ape->finalframeblocks     = get_le32(pb);        if (ape->formatflags & MAC_FORMAT_FLAG_HAS_PEAK_LEVEL) {            url_fseek(pb, 4, SEEK_CUR); /* Skip the peak level */            ape->headerlength += 4;        }        if (ape->formatflags & MAC_FORMAT_FLAG_HAS_SEEK_ELEMENTS) {            ape->seektablelength = get_le32(pb);            ape->headerlength += 4;            ape->seektablelength *= sizeof(int32_t);        } else            ape->seektablelength = ape->totalframes * sizeof(int32_t);        if (ape->formatflags & MAC_FORMAT_FLAG_8_BIT)            ape->bps = 8;        else if (ape->formatflags & MAC_FORMAT_FLAG_24_BIT)            ape->bps = 24;        else            ape->bps = 16;        if (ape->fileversion >= 3950)            ape->blocksperframe = 73728 * 4;        else if (ape->fileversion >= 3900 || (ape->fileversion >= 3800  && ape->compressiontype >= 4000))            ape->blocksperframe = 73728;        else            ape->blocksperframe = 9216;        /* Skip any stored wav header */        if (!(ape->formatflags & MAC_FORMAT_FLAG_CREATE_WAV_HEADER))            url_fskip(pb, ape->wavheaderlength);    }    if(ape->totalframes > UINT_MAX / sizeof(APEFrame)){        av_log(s, AV_LOG_ERROR, "Too many frames: %d\n", ape->totalframes);        return -1;    }    ape->frames       = av_malloc(ape->totalframes * sizeof(APEFrame));    if(!ape->frames)        return AVERROR_NOMEM;    ape->firstframe   = ape->junklength + ape->descriptorlength + ape->headerlength + ape->seektablelength + ape->wavheaderlength;    ape->currentframe = 0;    ape->totalsamples = ape->finalframeblocks;    if (ape->totalframes > 1)        ape->totalsamples += ape->blocksperframe * (ape->totalframes - 1);    if (ape->seektablelength > 0) {        ape->seektable = av_malloc(ape->seektablelength);        for (i = 0; i < ape->seektablelength / sizeof(uint32_t); i++)            ape->seektable[i] = get_le32(pb);    }    ape->frames[0].pos     = ape->firstframe;    ape->frames[0].nblocks = ape->blocksperframe;    ape->frames[0].skip    = 0;    for (i = 1; i < ape->totalframes; i++) {        ape->frames[i].pos      = ape->seektable[i]; //ape->frames[i-1].pos + ape->blocksperframe;        ape->frames[i].nblocks  = ape->blocksperframe;        ape->frames[i - 1].size = ape->frames[i].pos - ape->frames[i - 1].pos;        ape->frames[i].skip     = (ape->frames[i].pos - ape->frames[0].pos) & 3;    }    ape->frames[ape->totalframes - 1].size    = ape->finalframeblocks * 4;    ape->frames[ape->totalframes - 1].nblocks = ape->finalframeblocks;    for (i = 0; i < ape->totalframes; i++) {        if(ape->frames[i].skip){            ape->frames[i].pos  -= ape->frames[i].skip;            ape->frames[i].size += ape->frames[i].skip;        }        ape->frames[i].size = (ape->frames[i].size + 3) & ~3;    }    ape_dumpinfo(ape);    /* try to read APE tags */    if (!url_is_streamed(pb)) {        ape_parse_tag(s);        url_fseek(pb, 0, SEEK_SET);    }    av_log(s, AV_LOG_DEBUG, "Decoding file - v%d.%02d, compression level %d\n", ape->fileversion / 1000, (ape->fileversion % 1000) / 10, ape->compressiontype);    /* now we are ready: build format streams */    st = av_new_stream(s, 0);    if (!st)        return -1;    total_blocks = (ape->totalframes == 0) ? 0 : ((ape->totalframes - 1) * ape->blocksperframe) + ape->finalframeblocks;    st->codec->codec_type      = CODEC_TYPE_AUDIO;    st->codec->codec_id        = CODEC_ID_APE;    st->codec->codec_tag       = MKTAG('A', 'P', 'E', ' ');    st->codec->channels        = ape->channels;    st->codec->sample_rate     = ape->samplerate;    st->codec->bits_per_sample = ape->bps;    st->codec->frame_size      = MAC_SUBFRAME_SIZE;    st->nb_frames = ape->totalframes;    s->start_time = 0;    s->duration   = (int64_t) total_blocks * AV_TIME_BASE / ape->samplerate;    av_set_pts_info(st, 64, MAC_SUBFRAME_SIZE, ape->samplerate);    st->codec->extradata = av_malloc(APE_EXTRADATA_SIZE);    st->codec->extradata_size = APE_EXTRADATA_SIZE;    AV_WL16(st->codec->extradata + 0, ape->fileversion);    AV_WL16(st->codec->extradata + 2, ape->compressiontype);    AV_WL16(st->codec->extradata + 4, ape->formatflags);    pts = 0;    for (i = 0; i < ape->totalframes; i++) {        ape->frames[i].pts = pts;        av_add_index_entry(st, ape->frames[i].pos, ape->frames[i].pts, 0, 0, AVINDEX_KEYFRAME);        pts += ape->blocksperframe / MAC_SUBFRAME_SIZE;    }    return 0;}static int ape_read_packet(AVFormatContext * s, AVPacket * pkt){    int ret;    int nblocks;    APEContext *ape = s->priv_data;    uint32_t extra_size = 8;    if (url_feof(s->pb))        return AVERROR_IO;    if (ape->currentframe > ape->totalframes)        return AVERROR_IO;    url_fseek (s->pb, ape->frames[ape->currentframe].pos, SEEK_SET);    /* Calculate how many blocks there are in this frame */    if (ape->currentframe == (ape->totalframes - 1))        nblocks = ape->finalframeblocks;    else        nblocks = ape->blocksperframe;    if (av_new_packet(pkt,  ape->frames[ape->currentframe].size + extra_size) < 0)        return AVERROR_NOMEM;    AV_WL32(pkt->data    , nblocks);    AV_WL32(pkt->data + 4, ape->frames[ape->currentframe].skip);    ret = get_buffer(s->pb, pkt->data + extra_size, ape->frames[ape->currentframe].size);    pkt->pts = ape->frames[ape->currentframe].pts;    pkt->stream_index = 0;    /* note: we need to modify the packet size here to handle the last       packet */    pkt->size = ret + extra_size;    ape->currentframe++;    return 0;}static int ape_read_close(AVFormatContext * s){    APEContext *ape = s->priv_data;    av_freep(&ape->frames);    av_freep(&ape->seektable);    return 0;}static int ape_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags){    AVStream *st = s->streams[stream_index];    APEContext *ape = s->priv_data;    int index = av_index_search_timestamp(st, timestamp, flags);    if (index < 0)        return -1;    ape->currentframe = index;    return 0;}AVInputFormat ape_demuxer = {    "ape",    NULL_IF_CONFIG_SMALL("Monkey's Audio"),    sizeof(APEContext),    ape_probe,    ape_read_header,    ape_read_packet,    ape_read_close,    ape_read_seek,    .extensions = "ape,apl,mac"};