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/*
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 * NellyMoser audio decoder
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 * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
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 *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
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 *                    520e17cd55896441042b14df2566a6eb610ed444
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 * Copyright (c) 2007 Loic Minier <lool at dooz.org>
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 *                    Benjamin Larsson
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 *
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 * Permission is hereby granted, free of charge, to any person obtaining a
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 * copy of this software and associated documentation files (the "Software"),
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 * to deal in the Software without restriction, including without limitation
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 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
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 * and/or sell copies of the Software, and to permit persons to whom the
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 * Software is furnished to do so, subject to the following conditions:
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 *
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 * The above copyright notice and this permission notice shall be included in
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 * all copies or substantial portions of the Software.
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 *
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 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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 * DEALINGS IN THE SOFTWARE.
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 */
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/**
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 * @file nellymoserdec.c
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 * The 3 alphanumeric copyright notices are md5summed they are from the original
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 * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
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 */
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#include "avcodec.h"
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#include "random.h"
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#include "dsputil.h"
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#define ALT_BITSTREAM_READER_LE
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#include "bitstream.h"
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#define NELLY_BANDS       23
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#define NELLY_BLOCK_LEN   64
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#define NELLY_HEADER_BITS 116
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#define NELLY_DETAIL_BITS 198
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#define NELLY_BUF_LEN     128
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#define NELLY_FILL_LEN    124
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#define NELLY_BIT_CAP     6
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#define NELLY_BASE_OFF    4228
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#define NELLY_BASE_SHIFT  19
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#define NELLY_SAMPLES     (2 * NELLY_BUF_LEN)
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static const float dequantization_table[127] = {
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0.0000000000,-0.8472560048, 0.7224709988, -1.5247479677, -0.4531480074, 0.3753609955, 1.4717899561,
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-1.9822579622, -1.1929379702, -0.5829370022, -0.0693780035, 0.3909569979,0.9069200158, 1.4862740040,
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 2.2215409279, -2.3887870312, -1.8067539930, -1.4105420113, -1.0773609877, -0.7995010018,-0.5558109879,
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-0.3334020078, -0.1324490011, 0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398,
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1.3954459429, 1.8098750114, 2.3918759823,-2.3893830776, -1.9884680510, -1.7514040470, -1.5643119812,
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-1.3922129869,-1.2164649963, -1.0469499826, -0.8905100226, -0.7645580173, -0.6454579830, -0.5259280205,
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-0.4059549868, -0.3029719889, -0.2096900046, -0.1239869967, -0.0479229987, 0.0257730000, 0.1001340002,
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0.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119, 0.8425520062,
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1.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354,
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-2.5756309032, -2.0573320389, -1.8984919786, -1.7727810144, -1.6662600040, -1.5742180347, -1.4993319511,
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-1.4316639900, -1.3652280569, -1.3000990152, -1.2280930281, -1.1588579416, -1.0921250582, -1.0135740042,
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-0.9202849865, -0.8287050128, -0.7374889851, -0.6447759867, -0.5590940118, -0.4857139885, -0.4110319912,
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-0.3459700048, -0.2851159871, -0.2341620028, -0.1870580018, -0.1442500055, -0.1107169986, -0.0739680007,
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-0.0365610011, -0.0073290002, 0.0203610007, 0.0479039997, 0.0751969963, 0.0980999991, 0.1220389977,
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0.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984, 0.2870100141, 0.3197099864,
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0.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058, 0.6122040153,
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0.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075,
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1.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547,
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 2.2903931141
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};
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static const uint8_t nelly_band_sizes_table[NELLY_BANDS] = {
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2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15
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};
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static const uint16_t nelly_init_table[64] = {
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3134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770,
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12116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824,
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16157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078,
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19381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453,
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22756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730,
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26120, 26497, 26895, 27344, 27877, 28463, 29426, 31355
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};
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static const int16_t nelly_delta_table[32] = {
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-11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596,
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-2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433,
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2968, 3569, 4314, 5279, 6622, 8154, 10076, 12975
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};
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typedef struct NellyMoserDecodeContext {
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    AVCodecContext* avctx;
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    DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]);
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    float           state[64];
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    AVRandomState   random_state;
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    GetBitContext   gb;
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    int             add_bias;
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    int             scale_bias;
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    DSPContext      dsp;
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    MDCTContext     imdct_ctx;
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    DECLARE_ALIGNED_16(float,imdct_tmp[NELLY_BUF_LEN]);
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    DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]);
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} NellyMoserDecodeContext;
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static DECLARE_ALIGNED_16(float,sine_window[128]);
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static inline int signed_shift(int i, int shift) {
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    if (shift > 0)
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        return i << shift;
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    return i >> -shift;
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}
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static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio, float *a_in)
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{
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    int bot, top, top2;
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    bot = 0;
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    top = NELLY_BUF_LEN-1;
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    while (bot < NELLY_BUF_LEN/2) {
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        audio[bot] = ( a_in[bot]*sine_window[bot]+state[bot]*sine_window[top])/s->scale_bias + s->add_bias;
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        audio[top] = ( a_in[top]*sine_window[top]+state[bot]*sine_window[bot])/s->scale_bias + s->add_bias;
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        state[bot] = a_in[bot + NELLY_BUF_LEN];
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        bot++;
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        top--;
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    }
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}
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static int sum_bits(short *buf, short shift, short off)
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{
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    int b, i = 0, ret = 0;
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    for (i = 0; i < NELLY_FILL_LEN; i++) {
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        b = buf[i]-off;
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        b = ((b>>(shift-1))+1)>>1;
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        ret += av_clip(b, 0, NELLY_BIT_CAP);
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    }
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    return ret;
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}
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static int headroom(int *la)
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{
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    int l;
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    if (*la == 0) {
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        return 31;
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    }
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    l = 30 - av_log2(FFABS(*la));
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    *la <<= l;
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    return l;
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}
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static void get_sample_bits(const float *buf, int *bits)
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{
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    int i, j;
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    short sbuf[128];
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    int bitsum = 0, last_bitsum, small_bitsum, big_bitsum;
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    short shift, shift_saved;
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    int max, sum, last_off, tmp;
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    int big_off, small_off;
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    int off;
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    max = 0;
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    for (i = 0; i < NELLY_FILL_LEN; i++) {
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        max = FFMAX(max, buf[i]);
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    }
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    shift = -16;
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    shift += headroom(&max);
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    sum = 0;
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    for (i = 0; i < NELLY_FILL_LEN; i++) {
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        sbuf[i] = signed_shift(buf[i], shift);
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        sbuf[i] = (3*sbuf[i])>>2;
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        sum += sbuf[i];
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    }
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    shift += 11;
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    shift_saved = shift;
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    sum -= NELLY_DETAIL_BITS << shift;
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    shift += headroom(&sum);
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    small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15;
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    shift = shift_saved - (NELLY_BASE_SHIFT+shift-31);
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    small_off = signed_shift(small_off, shift);
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    bitsum = sum_bits(sbuf, shift_saved, small_off);
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    if (bitsum != NELLY_DETAIL_BITS) {
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        shift = 0;
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        off = bitsum - NELLY_DETAIL_BITS;
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        for(shift=0; FFABS(off) <= 16383; shift++)
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            off *= 2;
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        off = (off * NELLY_BASE_OFF) >> 15;
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        shift = shift_saved-(NELLY_BASE_SHIFT+shift-15);
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        off = signed_shift(off, shift);
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204
        for (j = 1; j < 20; j++) {
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            last_off = small_off;
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            small_off += off;
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            last_bitsum = bitsum;
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209
            bitsum = sum_bits(sbuf, shift_saved, small_off);
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211
            if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0)
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                break;
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        }
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        if (bitsum > NELLY_DETAIL_BITS) {
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            big_off = small_off;
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            small_off = last_off;
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            big_bitsum=bitsum;
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            small_bitsum=last_bitsum;
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        } else {
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            big_off = last_off;
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            big_bitsum=last_bitsum;
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            small_bitsum=bitsum;
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        }
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        while (bitsum != NELLY_DETAIL_BITS && j <= 19) {
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            off = (big_off+small_off)>>1;
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            bitsum = sum_bits(sbuf, shift_saved, off);
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            if (bitsum > NELLY_DETAIL_BITS) {
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                big_off=off;
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                big_bitsum=bitsum;
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            } else {
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                small_off = off;
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                small_bitsum=bitsum;
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            }
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            j++;
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        }
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        if (abs(big_bitsum-NELLY_DETAIL_BITS) >=
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            abs(small_bitsum-NELLY_DETAIL_BITS)) {
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            bitsum = small_bitsum;
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        } else {
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            small_off = big_off;
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            bitsum = big_bitsum;
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        }
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    }
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    for (i = 0; i < NELLY_FILL_LEN; i++) {
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        tmp = sbuf[i]-small_off;
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        tmp = ((tmp>>(shift_saved-1))+1)>>1;
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        bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP);
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    }
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    if (bitsum > NELLY_DETAIL_BITS) {
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        tmp = i = 0;
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        while (tmp < NELLY_DETAIL_BITS) {
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            tmp += bits[i];
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            i++;
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        }
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        bits[i-1] -= tmp - NELLY_DETAIL_BITS;
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        for(; i < NELLY_FILL_LEN; i++)
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            bits[i] = 0;
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    }
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}
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void nelly_decode_block(NellyMoserDecodeContext *s, const unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES])
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{
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    int i,j;
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    float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
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    float *aptr, *bptr, *pptr, val, pval;
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    int bits[NELLY_BUF_LEN];
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    unsigned char v;
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    init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
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    bptr = buf;
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    pptr = pows;
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    val = nelly_init_table[get_bits(&s->gb, 6)];
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    for (i=0 ; i<NELLY_BANDS ; i++) {
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        if (i > 0)
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            val += nelly_delta_table[get_bits(&s->gb, 5)];
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        pval = pow(2, val/2048);
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        for (j = 0; j < nelly_band_sizes_table[i]; j++) {
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            *bptr++ = val;
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            *pptr++ = pval;
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        }
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    }
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    get_sample_bits(buf, bits);
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    for (i = 0; i < 2; i++) {
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        aptr = audio + i * NELLY_BUF_LEN;
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        init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
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        skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
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        for (j = 0; j < NELLY_FILL_LEN; j++) {
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            if (bits[j] <= 0) {
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                aptr[j] = M_SQRT1_2*pows[j];
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                if (!(av_random(&s->random_state) & 1))
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                    aptr[j] *= -1.0;
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            } else {
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                v = get_bits(&s->gb, bits[j]);
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                aptr[j] = -dequantization_table[(1<<bits[j])-1+v]*pows[j];
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            }
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        }
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        memset(&aptr[NELLY_FILL_LEN], 0,
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               (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
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        s->imdct_ctx.fft.imdct_calc(&s->imdct_ctx, s->imdct_out,
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                                    aptr, s->imdct_tmp);
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        /* XXX: overlapping and windowing should be part of a more
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           generic imdct function */
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        overlap_and_window(s, s->state, aptr, s->imdct_out);
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    }
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}
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static av_cold int decode_init(AVCodecContext * avctx) {
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    NellyMoserDecodeContext *s = avctx->priv_data;
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    int i;
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    s->avctx = avctx;
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    av_init_random(0, &s->random_state);
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    ff_mdct_init(&s->imdct_ctx, 8, 1);
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328
    dsputil_init(&s->dsp, avctx);
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330
    if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
331
        s->add_bias = 385;
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        s->scale_bias = 8*32768;
333
    } else {
334
        s->add_bias = 0;
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        s->scale_bias = 1*8;
336
    }
337

    
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    /* Generate overlap window */
339
    if (!sine_window[0])
340
        for (i=0 ; i<128; i++) {
341
            sine_window[i] = sin((i + 0.5) / 256.0 * M_PI);
342
        }
343

    
344
    return 0;
345
}
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static int decode_tag(AVCodecContext * avctx,
348
                      void *data, int *data_size,
349
                      const uint8_t * buf, int buf_size) {
350
    NellyMoserDecodeContext *s = avctx->priv_data;
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    int blocks, i;
352
    int16_t* samples;
353
    *data_size = 0;
354
    samples = (int16_t*)data;
355

    
356
    if (buf_size < avctx->block_align)
357
        return buf_size;
358

    
359
    switch (buf_size) {
360
        case 64:    // 8000Hz
361
            blocks = 1; break;
362
        case 128:   // 11025Hz
363
            blocks = 2; break;
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        case 256:   // 22050Hz
365
            blocks = 4; break;
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        case 512:   // 44100Hz
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            blocks = 8; break;
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        default:
369
            av_log(avctx, AV_LOG_ERROR, "Tag size %d unknown, report sample!\n", buf_size);
370
            return buf_size;
371
    }
372

    
373
    for (i=0 ; i<blocks ; i++) {
374
        nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
375
        s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
376
        *data_size += NELLY_SAMPLES*sizeof(int16_t);
377
    }
378

    
379
    return buf_size;
380
}
381

    
382
static av_cold int decode_end(AVCodecContext * avctx) {
383
    NellyMoserDecodeContext *s = avctx->priv_data;
384

    
385
    ff_mdct_end(&s->imdct_ctx);
386
    return 0;
387
}
388

    
389
AVCodec nellymoser_decoder = {
390
    "nellymoser",
391
    CODEC_TYPE_AUDIO,
392
    CODEC_ID_NELLYMOSER,
393
    sizeof(NellyMoserDecodeContext),
394
    decode_init,
395
    NULL,
396
    decode_end,
397
    decode_tag,
398
};
399