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/*
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 * Musepack SV8 decoder
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 * Copyright (c) 2007 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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/**
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 * @file libavcodec/mpc8.c Musepack SV8 decoder
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 * MPEG Audio Layer 1/2 -like codec with frames of 1152 samples
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 * divided into 32 subbands.
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 */
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#include "libavutil/lfg.h"
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#include "avcodec.h"
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#include "get_bits.h"
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#include "dsputil.h"
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#include "mpegaudio.h"
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#include "mpc.h"
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#include "mpcdata.h"
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#include "mpc8data.h"
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#include "mpc8huff.h"
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static VLC band_vlc, scfi_vlc[2], dscf_vlc[2], res_vlc[2];
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static VLC q1_vlc, q2_vlc[2], q3_vlc[2], quant_vlc[4][2], q9up_vlc;
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static const int q3_offsets[2] = { MPC8_Q3_OFFSET, MPC8_Q4_OFFSET };
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static const int quant_offsets[6] = { MPC8_Q5_OFFSET, MPC8_Q6_OFFSET, MPC8_Q7_OFFSET, MPC8_Q8_OFFSET };
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static inline int mpc8_dec_base(GetBitContext *gb, int k, int n)
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{
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    int code = get_bits(gb, mpc8_cnk_len[k-1][n-1] - 1);
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    if (code >= mpc8_cnk_lost[k-1][n-1])
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        code = ((code << 1) | get_bits1(gb)) - mpc8_cnk_lost[k-1][n-1];
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    return code;
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}
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static inline int mpc8_dec_enum(GetBitContext *gb, int k, int n)
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{
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    int bits = 0;
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    const uint32_t * C = mpc8_cnk[k-1];
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    int code = mpc8_dec_base(gb, k, n);
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    do {
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        n--;
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        if (code >= C[n]) {
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            bits |= 1 << n;
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            code -= C[n];
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            C -= 32;
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            k--;
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        }
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    } while(k > 0);
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    return bits;
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}
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static inline int mpc8_get_mod_golomb(GetBitContext *gb, int m)
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{
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    if(mpc8_cnk_len[0][m] < 1) return 0;
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    return mpc8_dec_base(gb, 1, m+1);
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}
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static int mpc8_get_mask(GetBitContext *gb, int size, int t)
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{
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    int mask = 0;
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    if(t && t != size)
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         mask = mpc8_dec_enum(gb, FFMIN(t, size - t), size);
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    if((t << 1) > size) mask = ~mask;
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    return mask;
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}
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static av_cold int mpc8_decode_init(AVCodecContext * avctx)
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{
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    int i;
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    MPCContext *c = avctx->priv_data;
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    GetBitContext gb;
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    static int vlc_initialized = 0;
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    if(avctx->extradata_size < 2){
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        av_log(avctx, AV_LOG_ERROR, "Too small extradata size (%i)!\n", avctx->extradata_size);
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        return -1;
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    }
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    memset(c->oldDSCF, 0, sizeof(c->oldDSCF));
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    av_lfg_init(&c->rnd, 0xDEADBEEF);
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    dsputil_init(&c->dsp, avctx);
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    ff_mpc_init();
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    init_get_bits(&gb, avctx->extradata, 16);
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    skip_bits(&gb, 3);//sample rate
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    c->maxbands = get_bits(&gb, 5) + 1;
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    skip_bits(&gb, 4);//channels
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    c->MSS = get_bits1(&gb);
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    c->frames = 1 << (get_bits(&gb, 3) * 2);
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    if(vlc_initialized) return 0;
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    av_log(avctx, AV_LOG_DEBUG, "Initing VLC\n");
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    init_vlc(&band_vlc, MPC8_BANDS_BITS, MPC8_BANDS_SIZE,
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             mpc8_bands_bits,  1, 1,
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             mpc8_bands_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&q1_vlc, MPC8_Q1_BITS, MPC8_Q1_SIZE,
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             mpc8_q1_bits,  1, 1,
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             mpc8_q1_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&q9up_vlc, MPC8_Q9UP_BITS, MPC8_Q9UP_SIZE,
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             mpc8_q9up_bits,  1, 1,
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             mpc8_q9up_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&scfi_vlc[0], MPC8_SCFI0_BITS, MPC8_SCFI0_SIZE,
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             mpc8_scfi0_bits,  1, 1,
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             mpc8_scfi0_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&scfi_vlc[1], MPC8_SCFI1_BITS, MPC8_SCFI1_SIZE,
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             mpc8_scfi1_bits,  1, 1,
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             mpc8_scfi1_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&dscf_vlc[0], MPC8_DSCF0_BITS, MPC8_DSCF0_SIZE,
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             mpc8_dscf0_bits,  1, 1,
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             mpc8_dscf0_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc(&dscf_vlc[1], MPC8_DSCF1_BITS, MPC8_DSCF1_SIZE,
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             mpc8_dscf1_bits,  1, 1,
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             mpc8_dscf1_codes, 1, 1, INIT_VLC_USE_STATIC);
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    init_vlc_sparse(&q3_vlc[0], MPC8_Q3_BITS, MPC8_Q3_SIZE,
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             mpc8_q3_bits,  1, 1,
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             mpc8_q3_codes, 1, 1,
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             mpc8_q3_syms,  1, 1, INIT_VLC_USE_STATIC);
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    init_vlc_sparse(&q3_vlc[1], MPC8_Q4_BITS, MPC8_Q4_SIZE,
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             mpc8_q4_bits,  1, 1,
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             mpc8_q4_codes, 1, 1,
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             mpc8_q4_syms,  1, 1, INIT_VLC_USE_STATIC);
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    for(i = 0; i < 2; i++){
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        init_vlc(&res_vlc[i], MPC8_RES_BITS, MPC8_RES_SIZE,
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                 &mpc8_res_bits[i],  1, 1,
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                 &mpc8_res_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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        init_vlc(&q2_vlc[i], MPC8_Q2_BITS, MPC8_Q2_SIZE,
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                 &mpc8_q2_bits[i],  1, 1,
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                 &mpc8_q2_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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        init_vlc(&quant_vlc[0][i], MPC8_Q5_BITS, MPC8_Q5_SIZE,
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                 &mpc8_q5_bits[i],  1, 1,
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                 &mpc8_q5_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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        init_vlc(&quant_vlc[1][i], MPC8_Q6_BITS, MPC8_Q6_SIZE,
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                 &mpc8_q6_bits[i],  1, 1,
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                 &mpc8_q6_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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        init_vlc(&quant_vlc[2][i], MPC8_Q7_BITS, MPC8_Q7_SIZE,
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                 &mpc8_q7_bits[i],  1, 1,
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                 &mpc8_q7_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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        init_vlc(&quant_vlc[3][i], MPC8_Q8_BITS, MPC8_Q8_SIZE,
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                 &mpc8_q8_bits[i],  1, 1,
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                 &mpc8_q8_codes[i], 1, 1, INIT_VLC_USE_STATIC);
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    }
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    vlc_initialized = 1;
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    avctx->sample_fmt = SAMPLE_FMT_S16;
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    avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;
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    return 0;
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}
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static int mpc8_decode_frame(AVCodecContext * avctx,
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                            void *data, int *data_size,
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                            AVPacket *avpkt)
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{
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    const uint8_t *buf = avpkt->data;
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    int buf_size = avpkt->size;
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    MPCContext *c = avctx->priv_data;
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    GetBitContext gb2, *gb = &gb2;
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    int i, j, k, ch, cnt, res, t;
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    Band *bands = c->bands;
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    int off;
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    int maxband, keyframe;
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    int last[2];
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    keyframe = c->cur_frame == 0;
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    if(keyframe){
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        memset(c->Q, 0, sizeof(c->Q));
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        c->last_bits_used = 0;
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    }
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    init_get_bits(gb, buf, buf_size * 8);
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    skip_bits(gb, c->last_bits_used & 7);
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    if(keyframe)
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        maxband = mpc8_get_mod_golomb(gb, c->maxbands + 1);
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    else{
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        maxband = c->last_max_band + get_vlc2(gb, band_vlc.table, MPC8_BANDS_BITS, 2);
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        if(maxband > 32) maxband -= 33;
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    }
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    c->last_max_band = maxband;
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    /* read subband indexes */
213
    if(maxband){
214
        last[0] = last[1] = 0;
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        for(i = maxband - 1; i >= 0; i--){
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            for(ch = 0; ch < 2; ch++){
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                last[ch] = get_vlc2(gb, res_vlc[last[ch] > 2].table, MPC8_RES_BITS, 2) + last[ch];
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                if(last[ch] > 15) last[ch] -= 17;
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                bands[i].res[ch] = last[ch];
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            }
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        }
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        if(c->MSS){
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            int mask;
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            cnt = 0;
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            for(i = 0; i < maxband; i++)
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                if(bands[i].res[0] || bands[i].res[1])
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                    cnt++;
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            t = mpc8_get_mod_golomb(gb, cnt);
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            mask = mpc8_get_mask(gb, cnt, t);
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            for(i = maxband - 1; i >= 0; i--)
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                if(bands[i].res[0] || bands[i].res[1]){
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                    bands[i].msf = mask & 1;
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                    mask >>= 1;
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                }
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        }
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    }
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    for(i = maxband; i < c->maxbands; i++)
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        bands[i].res[0] = bands[i].res[1] = 0;
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    if(keyframe){
242
        for(i = 0; i < 32; i++)
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            c->oldDSCF[0][i] = c->oldDSCF[1][i] = 1;
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    }
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    for(i = 0; i < maxband; i++){
247
        if(bands[i].res[0] || bands[i].res[1]){
248
            cnt = !!bands[i].res[0] + !!bands[i].res[1] - 1;
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            if(cnt >= 0){
250
                t = get_vlc2(gb, scfi_vlc[cnt].table, scfi_vlc[cnt].bits, 1);
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                if(bands[i].res[0]) bands[i].scfi[0] = t >> (2 * cnt);
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                if(bands[i].res[1]) bands[i].scfi[1] = t & 3;
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            }
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        }
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    }
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    for(i = 0; i < maxband; i++){
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        for(ch = 0; ch < 2; ch++){
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            if(!bands[i].res[ch]) continue;
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261
            if(c->oldDSCF[ch][i]){
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                bands[i].scf_idx[ch][0] = get_bits(gb, 7) - 6;
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                c->oldDSCF[ch][i] = 0;
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            }else{
265
                t = get_vlc2(gb, dscf_vlc[1].table, MPC8_DSCF1_BITS, 2);
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                if(t == 64)
267
                    t += get_bits(gb, 6);
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                bands[i].scf_idx[ch][0] = ((bands[i].scf_idx[ch][2] + t - 25) & 0x7F) - 6;
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            }
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            for(j = 0; j < 2; j++){
271
                if((bands[i].scfi[ch] << j) & 2)
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                    bands[i].scf_idx[ch][j + 1] = bands[i].scf_idx[ch][j];
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                else{
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                    t = get_vlc2(gb, dscf_vlc[0].table, MPC8_DSCF0_BITS, 2);
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                    if(t == 31)
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                        t = 64 + get_bits(gb, 6);
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                    bands[i].scf_idx[ch][j + 1] = ((bands[i].scf_idx[ch][j] + t - 25) & 0x7F) - 6;
278
                }
279
            }
280
        }
281
    }
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283
    for(i = 0, off = 0; i < maxband; i++, off += SAMPLES_PER_BAND){
284
        for(ch = 0; ch < 2; ch++){
285
            res = bands[i].res[ch];
286
            switch(res){
287
            case -1:
288
                for(j = 0; j < SAMPLES_PER_BAND; j++)
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                    c->Q[ch][off + j] = (av_lfg_get(&c->rnd) & 0x3FC) - 510;
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                break;
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            case 0:
292
                break;
293
            case 1:
294
                for(j = 0; j < SAMPLES_PER_BAND; j += SAMPLES_PER_BAND / 2){
295
                    cnt = get_vlc2(gb, q1_vlc.table, MPC8_Q1_BITS, 2);
296
                    t = mpc8_get_mask(gb, 18, cnt);
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                    for(k = 0; k < SAMPLES_PER_BAND / 2; k++, t <<= 1)
298
                        c->Q[ch][off + j + k] = (t & 0x20000) ? (get_bits1(gb) << 1) - 1 : 0;
299
                }
300
                break;
301
            case 2:
302
                cnt = 6;//2*mpc8_thres[res]
303
                for(j = 0; j < SAMPLES_PER_BAND; j += 3){
304
                    t = get_vlc2(gb, q2_vlc[cnt > 3].table, MPC8_Q2_BITS, 2);
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                    c->Q[ch][off + j + 0] = mpc8_idx50[t];
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                    c->Q[ch][off + j + 1] = mpc8_idx51[t];
307
                    c->Q[ch][off + j + 2] = mpc8_idx52[t];
308
                    cnt = (cnt >> 1) + mpc8_huffq2[t];
309
                }
310
                break;
311
            case 3:
312
            case 4:
313
                for(j = 0; j < SAMPLES_PER_BAND; j += 2){
314
                    t = get_vlc2(gb, q3_vlc[res - 3].table, MPC8_Q3_BITS, 2) + q3_offsets[res - 3];
315
                    c->Q[ch][off + j + 1] = t >> 4;
316
                    c->Q[ch][off + j + 0] = (t & 8) ? (t & 0xF) - 16 : (t & 0xF);
317
                }
318
                break;
319
            case 5:
320
            case 6:
321
            case 7:
322
            case 8:
323
                cnt = 2 * mpc8_thres[res];
324
                for(j = 0; j < SAMPLES_PER_BAND; j++){
325
                    t = get_vlc2(gb, quant_vlc[res - 5][cnt > mpc8_thres[res]].table, quant_vlc[res - 5][cnt > mpc8_thres[res]].bits, 2) + quant_offsets[res - 5];
326
                    c->Q[ch][off + j] = t;
327
                    cnt = (cnt >> 1) + FFABS(c->Q[ch][off + j]);
328
                }
329
                break;
330
            default:
331
                for(j = 0; j < SAMPLES_PER_BAND; j++){
332
                    c->Q[ch][off + j] = get_vlc2(gb, q9up_vlc.table, MPC8_Q9UP_BITS, 2);
333
                    if(res != 9){
334
                        c->Q[ch][off + j] <<= res - 9;
335
                        c->Q[ch][off + j] |= get_bits(gb, res - 9);
336
                    }
337
                    c->Q[ch][off + j] -= (1 << (res - 2)) - 1;
338
                }
339
            }
340
        }
341
    }
342

    
343
    ff_mpc_dequantize_and_synth(c, maxband, data);
344

    
345
    c->cur_frame++;
346

    
347
    c->last_bits_used = get_bits_count(gb);
348
    if(c->cur_frame >= c->frames)
349
        c->cur_frame = 0;
350
    *data_size =  MPC_FRAME_SIZE * 4;
351

    
352
    return c->cur_frame ? c->last_bits_used >> 3 : buf_size;
353
}
354

    
355
AVCodec mpc8_decoder = {
356
    "mpc8",
357
    CODEC_TYPE_AUDIO,
358
    CODEC_ID_MUSEPACK8,
359
    sizeof(MPCContext),
360
    mpc8_decode_init,
361
    NULL,
362
    NULL,
363
    mpc8_decode_frame,
364
    .long_name = NULL_IF_CONFIG_SMALL("Musepack SV8"),
365
};