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/* 
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 * WAV encoder and decoder
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 * Copyright (c) 2001, 2002 Fabrice Bellard.
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 *
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 * This library 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 of the License, or (at your option) any later version.
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 *
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 * This library 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 this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 */
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#include "avformat.h"
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#include "avi.h"
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const CodecTag codec_wav_tags[] = {
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    { CODEC_ID_MP2, 0x50 },
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    { CODEC_ID_MP3LAME, 0x55 },
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    { CODEC_ID_AC3, 0x2000 },
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    { CODEC_ID_PCM_S16LE, 0x01 },
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    { CODEC_ID_PCM_U8, 0x01 }, /* must come after s16le in this list */
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    { CODEC_ID_PCM_ALAW, 0x06 },
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    { CODEC_ID_PCM_MULAW, 0x07 },
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    { CODEC_ID_ADPCM_MS, 0x02 },
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    { CODEC_ID_ADPCM_IMA_WAV, 0x11 },
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    { CODEC_ID_WMAV1, 0x160 },
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    { CODEC_ID_WMAV2, 0x161 },
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    { 0, 0 },
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};
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/* WAVEFORMATEX header */
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/* returns the size or -1 on error */
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int put_wav_header(ByteIOContext *pb, AVCodecContext *enc)
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{
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    int tag, bps, blkalign, bytespersec;
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    int hdrsize = 18;
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    tag = codec_get_tag(codec_wav_tags, enc->codec_id);
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    if (tag == 0)
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        return -1;
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    put_le16(pb, tag);
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    put_le16(pb, enc->channels);
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    put_le32(pb, enc->sample_rate);
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    if (enc->codec_id == CODEC_ID_PCM_U8 ||
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        enc->codec_id == CODEC_ID_PCM_ALAW ||
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        enc->codec_id == CODEC_ID_PCM_MULAW) {
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        bps = 8;
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    } else if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3LAME) {
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        bps = 0;
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    } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV || enc->codec_id == CODEC_ID_ADPCM_MS) {
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        bps = 4;
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    } else {
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        bps = 16;
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    }
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    if (enc->codec_id == CODEC_ID_MP2 || enc->codec_id == CODEC_ID_MP3LAME) {
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        blkalign = 1;
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        //blkalign = 144 * enc->bit_rate/enc->sample_rate;
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    } else if (enc->block_align != 0) { /* specified by the codec */
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        blkalign = enc->block_align;
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    } else
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        blkalign = enc->channels*bps >> 3;
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    if (enc->codec_id == CODEC_ID_PCM_U8 ||
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        enc->codec_id == CODEC_ID_PCM_S16LE) {
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        bytespersec = enc->sample_rate * blkalign;
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    } else {
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        bytespersec = enc->bit_rate / 8;
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    }
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    put_le32(pb, bytespersec); /* bytes per second */
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    put_le16(pb, blkalign); /* block align */
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    put_le16(pb, bps); /* bits per sample */
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    if (enc->codec_id == CODEC_ID_MP3LAME) {
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        put_le16(pb, 12); /* wav_extra_size */
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        hdrsize += 12;
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        put_le16(pb, 1); /* wID */
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        put_le32(pb, 2); /* fdwFlags */
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        put_le16(pb, 1152); /* nBlockSize */
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        put_le16(pb, 1); /* nFramesPerBlock */
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        put_le16(pb, 1393); /* nCodecDelay */
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    } else if (enc->codec_id == CODEC_ID_MP2) {
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        put_le16(pb, 22); /* wav_extra_size */
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        hdrsize += 22;
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        put_le16(pb, 2);  /* fwHeadLayer */
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        put_le32(pb, enc->bit_rate); /* dwHeadBitrate */
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        put_le16(pb, enc->channels == 2 ? 1 : 8); /* fwHeadMode */
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        put_le16(pb, 0);  /* fwHeadModeExt */
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        put_le16(pb, 1);  /* wHeadEmphasis */
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        put_le16(pb, 16); /* fwHeadFlags */
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        put_le32(pb, 0);  /* dwPTSLow */
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        put_le32(pb, 0);  /* dwPTSHigh */
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    } else if (enc->codec_id == CODEC_ID_ADPCM_IMA_WAV) {
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        put_le16(pb, 2); /* wav_extra_size */
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        put_le16(pb, ((enc->block_align - 4 * enc->channels) / (4 * enc->channels)) * 8 + 1); /* wSamplesPerBlock */
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    } else
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        put_le16(pb, 0); /* wav_extra_size */
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    return hdrsize;
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}
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void get_wav_header(ByteIOContext *pb, AVCodecContext *codec, 
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                    int has_extra_data)
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{
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    int id;
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    id = get_le16(pb);
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    codec->codec_type = CODEC_TYPE_AUDIO;
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    codec->codec_tag = id;
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    codec->fourcc = id;
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    codec->channels = get_le16(pb);
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    codec->sample_rate = get_le32(pb);
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    codec->bit_rate = get_le32(pb) * 8;
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    codec->block_align = get_le16(pb);
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    codec->frame_bits = get_le16(pb); /* bits per sample */
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    codec->codec_id = wav_codec_get_id(id, codec->frame_bits);
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    if (has_extra_data) {
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        codec->extradata_size = get_le16(pb);
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        if (codec->extradata_size > 0) {
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            codec->extradata = av_mallocz(codec->extradata_size);
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            get_buffer(pb, codec->extradata, codec->extradata_size);
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        }
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    }
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}
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int wav_codec_get_id(unsigned int tag, int bps)
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{
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    int id;
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    id = codec_get_id(codec_wav_tags, tag);
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    if (id <= 0)
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        return id;
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    /* handle specific u8 codec */
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    if (id == CODEC_ID_PCM_S16LE && bps == 8)
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        id = CODEC_ID_PCM_U8;
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    return id;
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}
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typedef struct {
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    offset_t data;
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} WAVContext;
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static int wav_write_header(AVFormatContext *s)
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{
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    WAVContext *wav = s->priv_data;
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    ByteIOContext *pb = &s->pb;
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    offset_t fmt;
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    put_tag(pb, "RIFF");
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    put_le32(pb, 0); /* file length */
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    put_tag(pb, "WAVE");
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    /* format header */
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    fmt = start_tag(pb, "fmt ");
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    if (put_wav_header(pb, &s->streams[0]->codec) < 0) {
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        av_free(wav);
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        return -1;
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    }
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    end_tag(pb, fmt);
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    /* data header */
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    wav->data = start_tag(pb, "data");
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    put_flush_packet(pb);
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    return 0;
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}
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static int wav_write_packet(AVFormatContext *s, int stream_index_ptr,
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                           UINT8 *buf, int size, int force_pts)
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{
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    ByteIOContext *pb = &s->pb;
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    put_buffer(pb, buf, size);
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    return 0;
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}
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static int wav_write_trailer(AVFormatContext *s)
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{
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    ByteIOContext *pb = &s->pb;
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    WAVContext *wav = s->priv_data;
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    offset_t file_size;
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    if (!url_is_streamed(&s->pb)) {
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        end_tag(pb, wav->data);
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        /* update file size */
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        file_size = url_ftell(pb);
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        url_fseek(pb, 4, SEEK_SET);
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        put_le32(pb, (UINT32)(file_size - 8));
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        url_fseek(pb, file_size, SEEK_SET);
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        put_flush_packet(pb);
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    }
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    return 0;
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}
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/* return the size of the found tag */
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/* XXX: > 2GB ? */
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static int find_tag(ByteIOContext *pb, UINT32 tag1)
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{
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    unsigned int tag;
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    int size;
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    for(;;) {
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        if (url_feof(pb))
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            return -1;
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        tag = get_le32(pb);
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        size = get_le32(pb);
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        if (tag == tag1)
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            break;
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        url_fseek(pb, size, SEEK_CUR);
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    }
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    if (size < 0)
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        size = 0x7fffffff;
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    return size;
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}
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static int wav_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] == 'R' && p->buf[1] == 'I' &&
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        p->buf[2] == 'F' && p->buf[3] == 'F' &&
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        p->buf[8] == 'W' && p->buf[9] == 'A' &&
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        p->buf[10] == 'V' && p->buf[11] == 'E')
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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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/* wav input */
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static int wav_read_header(AVFormatContext *s,
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                           AVFormatParameters *ap)
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{
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    int size;
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    unsigned int tag;
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    ByteIOContext *pb = &s->pb;
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    AVStream *st;
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    /* check RIFF header */
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    tag = get_le32(pb);
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    if (tag != MKTAG('R', 'I', 'F', 'F'))
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        return -1;
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    get_le32(pb); /* file size */
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    tag = get_le32(pb);
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    if (tag != MKTAG('W', 'A', 'V', 'E'))
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        return -1;
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    /* parse fmt header */
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    size = find_tag(pb, MKTAG('f', 'm', 't', ' '));
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    if (size < 0)
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        return -1;
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    st = av_new_stream(s, 0);
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    if (!st)
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        return AVERROR_NOMEM;
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    get_wav_header(pb, &st->codec, (size >= 18));
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    size = find_tag(pb, MKTAG('d', 'a', 't', 'a'));
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    if (size < 0)
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        return -1;
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    return 0;
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}
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#define MAX_SIZE 4096
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static int wav_read_packet(AVFormatContext *s,
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                           AVPacket *pkt)
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{
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    int ret;
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    if (url_feof(&s->pb))
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        return -EIO;
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    if (av_new_packet(pkt, MAX_SIZE))
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        return -EIO;
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    pkt->stream_index = 0;
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    ret = get_buffer(&s->pb, pkt->data, pkt->size);
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    if (ret < 0)
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        av_free_packet(pkt);
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    /* note: we need to modify the packet size here to handle the last
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       packet */
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    pkt->size = ret;
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    return ret;
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}
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static int wav_read_close(AVFormatContext *s)
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{
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    return 0;
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}
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static AVInputFormat wav_iformat = {
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    "wav",
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    "wav format",
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    0,
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    wav_probe,
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    wav_read_header,
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    wav_read_packet,
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    wav_read_close,
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};
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static AVOutputFormat wav_oformat = {
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    "wav",
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    "wav format",
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    "audio/x-wav",
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    "wav",
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    sizeof(WAVContext),
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    CODEC_ID_PCM_S16LE,
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    CODEC_ID_NONE,
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    wav_write_header,
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    wav_write_packet,
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    wav_write_trailer,
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};
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int wav_init(void)
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{
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    av_register_input_format(&wav_iformat);
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    av_register_output_format(&wav_oformat);
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    return 0;
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}