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ffmpeg / libavformat / wv.c @ 4815e246

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/*
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 * WavPack demuxer
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 * Copyright (c) 2006 Konstantin Shishkov
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include "libavutil/intreadwrite.h"
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#include "avformat.h"
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// specs say that maximum block size is 1Mb
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#define WV_BLOCK_LIMIT 1047576
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#define WV_EXTRA_SIZE 12
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enum WV_FLAGS{
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    WV_MONO   = 0x0004,
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    WV_HYBRID = 0x0008,
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    WV_JOINT  = 0x0010,
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    WV_CROSSD = 0x0020,
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    WV_HSHAPE = 0x0040,
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    WV_FLOAT  = 0x0080,
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    WV_INT32  = 0x0100,
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    WV_HBR    = 0x0200,
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    WV_HBAL   = 0x0400,
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    WV_MCINIT = 0x0800,
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    WV_MCEND  = 0x1000,
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};
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static const int wv_rates[16] = {
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     6000,  8000,  9600, 11025, 12000, 16000, 22050, 24000,
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    32000, 44100, 48000, 64000, 88200, 96000, 192000, -1
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};
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typedef struct{
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    uint32_t blksize, flags;
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    int rate, chan, bpp;
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    uint32_t samples, soff;
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    int block_parsed;
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    uint8_t extra[WV_EXTRA_SIZE];
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    int64_t pos;
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}WVContext;
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static int wv_probe(AVProbeData *p)
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{
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    /* check file header */
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    if (p->buf_size <= 32)
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        return 0;
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    if (p->buf[0] == 'w' && p->buf[1] == 'v' &&
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        p->buf[2] == 'p' && p->buf[3] == 'k')
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        return AVPROBE_SCORE_MAX;
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    else
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        return 0;
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}
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static int wv_read_block_header(AVFormatContext *ctx, ByteIOContext *pb)
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{
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    WVContext *wc = ctx->priv_data;
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    uint32_t tag, ver;
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    int size;
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    int rate, bpp, chan;
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    wc->pos = url_ftell(pb);
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    tag = get_le32(pb);
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    if (tag != MKTAG('w', 'v', 'p', 'k'))
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        return -1;
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    size = get_le32(pb);
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    if(size < 24 || size > WV_BLOCK_LIMIT){
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        av_log(ctx, AV_LOG_ERROR, "Incorrect block size %i\n", size);
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        return -1;
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    }
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    wc->blksize = size;
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    ver = get_le16(pb);
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    if(ver < 0x402 || ver > 0x410){
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        av_log(ctx, AV_LOG_ERROR, "Unsupported version %03X\n", ver);
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        return -1;
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    }
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    get_byte(pb); // track no
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    get_byte(pb); // track sub index
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    wc->samples = get_le32(pb); // total samples in file
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    wc->soff = get_le32(pb); // offset in samples of current block
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    get_buffer(pb, wc->extra, WV_EXTRA_SIZE);
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    wc->flags = AV_RL32(wc->extra + 4);
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    //parse flags
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    if(wc->flags & WV_FLOAT){
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        av_log(ctx, AV_LOG_ERROR, "Floating point data is not supported\n");
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        return -1;
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    }
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    bpp = ((wc->flags & 3) + 1) << 3;
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    chan = 1 + !(wc->flags & WV_MONO);
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    rate = wv_rates[(wc->flags >> 23) & 0xF];
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    if(rate == -1){
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        av_log(ctx, AV_LOG_ERROR, "Unknown sampling rate\n");
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        return -1;
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    }
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    if(!wc->bpp) wc->bpp = bpp;
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    if(!wc->chan) wc->chan = chan;
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    if(!wc->rate) wc->rate = rate;
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    if(wc->flags && bpp != wc->bpp){
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        av_log(ctx, AV_LOG_ERROR, "Bits per sample differ, this block: %i, header block: %i\n", bpp, wc->bpp);
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        return -1;
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    }
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    if(wc->flags && chan != wc->chan){
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        av_log(ctx, AV_LOG_ERROR, "Channels differ, this block: %i, header block: %i\n", chan, wc->chan);
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        return -1;
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    }
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    if(wc->flags && rate != wc->rate){
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        av_log(ctx, AV_LOG_ERROR, "Sampling rate differ, this block: %i, header block: %i\n", rate, wc->rate);
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        return -1;
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    }
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    wc->blksize = size - 24;
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    return 0;
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}
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static int wv_read_header(AVFormatContext *s,
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                          AVFormatParameters *ap)
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{
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    ByteIOContext *pb = s->pb;
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    WVContext *wc = s->priv_data;
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    AVStream *st;
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    if(wv_read_block_header(s, pb) < 0)
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        return -1;
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    wc->block_parsed = 0;
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    /* now we are ready: build format streams */
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    st = av_new_stream(s, 0);
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    if (!st)
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        return -1;
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    st->codec->codec_type = CODEC_TYPE_AUDIO;
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    st->codec->codec_id = CODEC_ID_WAVPACK;
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    st->codec->channels = wc->chan;
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    st->codec->sample_rate = wc->rate;
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    st->codec->bits_per_coded_sample = wc->bpp;
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    av_set_pts_info(st, 64, 1, wc->rate);
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    s->start_time = 0;
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    s->duration = (int64_t)wc->samples * AV_TIME_BASE / st->codec->sample_rate;
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    return 0;
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}
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static int wv_read_packet(AVFormatContext *s,
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                          AVPacket *pkt)
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{
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    WVContext *wc = s->priv_data;
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    int ret;
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    if (url_feof(s->pb))
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        return AVERROR(EIO);
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    if(wc->block_parsed){
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        if(wv_read_block_header(s, s->pb) < 0)
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            return -1;
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    }
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    if(av_new_packet(pkt, wc->blksize + WV_EXTRA_SIZE) < 0)
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        return AVERROR(ENOMEM);
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    memcpy(pkt->data, wc->extra, WV_EXTRA_SIZE);
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    ret = get_buffer(s->pb, pkt->data + WV_EXTRA_SIZE, wc->blksize);
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    if(ret != wc->blksize){
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        av_free_packet(pkt);
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        return AVERROR(EIO);
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    }
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    pkt->stream_index = 0;
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    wc->block_parsed = 1;
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    pkt->size = ret + WV_EXTRA_SIZE;
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    pkt->pts = wc->soff;
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    av_add_index_entry(s->streams[0], wc->pos, pkt->pts, 0, 0, AVINDEX_KEYFRAME);
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    return 0;
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}
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static int wv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
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{
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    AVStream *st = s->streams[stream_index];
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    WVContext *wc = s->priv_data;
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    AVPacket pkt1, *pkt = &pkt1;
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    int ret;
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    int index = av_index_search_timestamp(st, timestamp, flags);
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    int64_t pos, pts;
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    /* if found, seek there */
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    if (index >= 0){
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        wc->block_parsed = 1;
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        url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
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        return 0;
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    }
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    /* if timestamp is out of bounds, return error */
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    if(timestamp < 0 || timestamp >= s->duration)
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        return -1;
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    pos = url_ftell(s->pb);
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    do{
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        ret = av_read_frame(s, pkt);
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        if (ret < 0){
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            url_fseek(s->pb, pos, SEEK_SET);
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            return -1;
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        }
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        pts = pkt->pts;
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        av_free_packet(pkt);
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    }while(pts < timestamp);
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    return 0;
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}
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AVInputFormat wv_demuxer = {
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    "wv",
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    NULL_IF_CONFIG_SMALL("WavPack"),
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    sizeof(WVContext),
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    wv_probe,
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    wv_read_header,
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    wv_read_packet,
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    NULL,
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    wv_read_seek,
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};