libavcodec/nellymoser.c

   1 /*
   2  * Common code between Nellymoser encoder and decoder
   3  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
   4  *                    539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
   5  *                    520e17cd55896441042b14df2566a6eb610ed444
   6  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
   7  *                    Benjamin Larsson
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the "Software"),
  11  * to deal in the Software without restriction, including without limitation
  12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  13  * and/or sell copies of the Software, and to permit persons to whom the
  14  * Software is furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  */
  27
  28 /**
  29  * @file
  30  * The 3 alphanumeric copyright notices are md5summed they are from the original
  31  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
  32  */
  33
  34 #include "libavutil/common.h"
  35
  36 #include "avcodec.h"
  37 #include "nellymoser.h"
  38
  39 const float ff_nelly_dequantization_table[127] = {
  40  0.0000000000,
  41
  42 -0.8472560048, 0.7224709988,
  43
  44 -1.5247479677,-0.4531480074, 0.3753609955, 1.4717899561,
  45
  46 -1.9822579622,-1.1929379702,-0.5829370022,-0.0693780035, 0.3909569979, 0.9069200158, 1.4862740040, 2.2215409279,
  47
  48 -2.3887870312,-1.8067539930,-1.4105420113,-1.0773609877,-0.7995010018,-0.5558109879,-0.3334020078,-0.1324490011,
  49  0.0568020009, 0.2548770010, 0.4773550034, 0.7386850119, 1.0443060398, 1.3954459429, 1.8098750114, 2.3918759823,
  50
  51 -2.3893830776,-1.9884680510,-1.7514040470,-1.5643119812,-1.3922129869,-1.2164649963,-1.0469499826,-0.8905100226,
  52 -0.7645580173,-0.6454579830,-0.5259280205,-0.4059549868,-0.3029719889,-0.2096900046,-0.1239869967,-0.0479229987,
  53  0.0257730000, 0.1001340002, 0.1737180054, 0.2585540116, 0.3522900045, 0.4569880068, 0.5767750144, 0.7003160119,
  54  0.8425520062, 1.0093879700, 1.1821349859, 1.3534560204, 1.5320819616, 1.7332619429, 1.9722349644, 2.3978140354,
  55
  56 -2.5756309032,-2.0573320389,-1.8984919786,-1.7727810144,-1.6662600040,-1.5742180347,-1.4993319511,-1.4316639900,
  57 -1.3652280569,-1.3000990152,-1.2280930281,-1.1588579416,-1.0921250582,-1.0135740042,-0.9202849865,-0.8287050128,
  58 -0.7374889851,-0.6447759867,-0.5590940118,-0.4857139885,-0.4110319912,-0.3459700048,-0.2851159871,-0.2341620028,
  59 -0.1870580018,-0.1442500055,-0.1107169986,-0.0739680007,-0.0365610011,-0.0073290002, 0.0203610007, 0.0479039997,
  60  0.0751969963, 0.0980999991, 0.1220389977, 0.1458999962, 0.1694349945, 0.1970459968, 0.2252430022, 0.2556869984,
  61  0.2870100141, 0.3197099864, 0.3525829911, 0.3889069855, 0.4334920049, 0.4769459963, 0.5204820037, 0.5644530058,
  62  0.6122040153, 0.6685929894, 0.7341650128, 0.8032159805, 0.8784040213, 0.9566209912, 1.0397069454, 1.1293770075,
  63  1.2211159468, 1.3080279827, 1.4024800062, 1.5056819916, 1.6227730513, 1.7724959850, 1.9430880547, 2.2903931141
  64 };
  65
  66 const uint8_t ff_nelly_band_sizes_table[NELLY_BANDS] = {
  67 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 4, 4, 5, 6, 6, 7, 8, 9, 10, 12, 14, 15
  68 };
  69
  70 const uint16_t ff_nelly_init_table[64] = {
  71 3134, 5342, 6870, 7792, 8569, 9185, 9744, 10191, 10631, 11061, 11434, 11770,
  72 12116, 12513, 12925, 13300, 13674, 14027, 14352, 14716, 15117, 15477, 15824,
  73 16157, 16513, 16804, 17090, 17401, 17679, 17948, 18238, 18520, 18764, 19078,
  74 19381, 19640, 19921, 20205, 20500, 20813, 21162, 21465, 21794, 22137, 22453,
  75 22756, 23067, 23350, 23636, 23926, 24227, 24521, 24819, 25107, 25414, 25730,
  76 26120, 26497, 26895, 27344, 27877, 28463, 29426, 31355
  77 };
  78
  79 const int16_t ff_nelly_delta_table[32] = {
  80 -11725, -9420, -7910, -6801, -5948, -5233, -4599, -4039, -3507, -3030, -2596,
  81 -2170, -1774, -1383, -1016, -660, -329, -1, 337, 696, 1085, 1512, 1962, 2433,
  82 2968, 3569, 4314, 5279, 6622, 8154, 10076, 12975
  83 };
  84
  85 static inline int signed_shift(int i, int shift) {
  86     if (shift > 0)
  87         return i << shift;
  88     return i >> -shift;
  89 }
  90
  91 static int sum_bits(short *buf, short shift, short off)
  92 {
  93     int i, ret = 0;
  94
  95     for (i = 0; i < NELLY_FILL_LEN; i++) {
  96         int b = buf[i]-off;
  97         b = ((b>>(shift-1))+1)>>1;
  98         ret += av_clip(b, 0, NELLY_BIT_CAP);
  99     }
 100
 101     return ret;
 102 }
 103
 104 static int headroom(int *la)
 105 {
 106     int l;
 107     if (*la == 0) {
 108         return 31;
 109     }
 110     l = 30 - av_log2(FFABS(*la));
 111     *la <<= l;
 112     return l;
 113 }
 114
 115
 116 void ff_nelly_get_sample_bits(const float *buf, int *bits)
 117 {
 118     int i, j;
 119     short sbuf[128];
 120     int bitsum = 0, last_bitsum, small_bitsum, big_bitsum;
 121     short shift, shift_saved;
 122     int max, sum, last_off, tmp;
 123     int big_off, small_off;
 124     int off;
 125
 126     max = 0;
 127     for (i = 0; i < NELLY_FILL_LEN; i++) {
 128         max = FFMAX(max, buf[i]);
 129     }
 130     shift = -16;
 131     shift += headroom(&max);
 132
 133     sum = 0;
 134     for (i = 0; i < NELLY_FILL_LEN; i++) {
 135         sbuf[i] = signed_shift(buf[i], shift);
 136         sbuf[i] = (3*sbuf[i])>>2;
 137         sum += sbuf[i];
 138     }
 139
 140     shift += 11;
 141     shift_saved = shift;
 142     sum -= NELLY_DETAIL_BITS << shift;
 143     shift += headroom(&sum);
 144     small_off = (NELLY_BASE_OFF * (sum>>16)) >> 15;
 145     shift = shift_saved - (NELLY_BASE_SHIFT+shift-31);
 146
 147     small_off = signed_shift(small_off, shift);
 148
 149     bitsum = sum_bits(sbuf, shift_saved, small_off);
 150
 151     if (bitsum != NELLY_DETAIL_BITS) {
 152         off = bitsum - NELLY_DETAIL_BITS;
 153
 154         for(shift=0; FFABS(off) <= 16383; shift++)
 155             off *= 2;
 156
 157         off = (off * NELLY_BASE_OFF) >> 15;
 158         shift = shift_saved-(NELLY_BASE_SHIFT+shift-15);
 159
 160         off = signed_shift(off, shift);
 161
 162         for (j = 1; j < 20; j++) {
 163             last_off = small_off;
 164             small_off += off;
 165             last_bitsum = bitsum;
 166
 167             bitsum = sum_bits(sbuf, shift_saved, small_off);
 168
 169             if ((bitsum-NELLY_DETAIL_BITS) * (last_bitsum-NELLY_DETAIL_BITS) <= 0)
 170                 break;
 171         }
 172
 173         if (bitsum > NELLY_DETAIL_BITS) {
 174             big_off = small_off;
 175             small_off = last_off;
 176             big_bitsum=bitsum;
 177             small_bitsum=last_bitsum;
 178         } else {
 179             big_off = last_off;
 180             big_bitsum=last_bitsum;
 181             small_bitsum=bitsum;
 182         }
 183
 184         while (bitsum != NELLY_DETAIL_BITS && j <= 19) {
 185             off = (big_off+small_off)>>1;
 186             bitsum = sum_bits(sbuf, shift_saved, off);
 187             if (bitsum > NELLY_DETAIL_BITS) {
 188                 big_off=off;
 189                 big_bitsum=bitsum;
 190             } else {
 191                 small_off = off;
 192                 small_bitsum=bitsum;
 193             }
 194             j++;
 195         }
 196
 197         if (abs(big_bitsum-NELLY_DETAIL_BITS) >=
 198             abs(small_bitsum-NELLY_DETAIL_BITS)) {
 199             bitsum = small_bitsum;
 200         } else {
 201             small_off = big_off;
 202             bitsum = big_bitsum;
 203         }
 204     }
 205
 206     for (i = 0; i < NELLY_FILL_LEN; i++) {
 207         tmp = sbuf[i]-small_off;
 208         tmp = ((tmp>>(shift_saved-1))+1)>>1;
 209         bits[i] = av_clip(tmp, 0, NELLY_BIT_CAP);
 210     }
 211
 212     if (bitsum > NELLY_DETAIL_BITS) {
 213         tmp = i = 0;
 214         while (tmp < NELLY_DETAIL_BITS) {
 215             tmp += bits[i];
 216             i++;
 217         }
 218
 219         bits[i-1] -= tmp - NELLY_DETAIL_BITS;
 220         for(; i < NELLY_FILL_LEN; i++)
 221             bits[i] = 0;
 222     }
 223 }