libavcodec/acelp_vectors.h

   1 /*
   2  * adaptive and fixed codebook vector operations for ACELP-based codecs
   3  *
   4  * Copyright (c) 2008 Vladimir Voroshilov
   5  *
   6  * This file is part of Libav.
   7  *
   8  * Libav is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * Libav is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with Libav; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #ifndef AVCODEC_ACELP_VECTORS_H
  24 #define AVCODEC_ACELP_VECTORS_H
  25
  26 #include <stdint.h>
  27
  28 /** Sparse representation for the algebraic codebook (fixed) vector */
  29 typedef struct AMRFixed {
  30     int      n;
  31     int      x[10];
  32     float    y[10];
  33     int      no_repeat_mask;
  34     int      pitch_lag;
  35     float    pitch_fac;
  36 } AMRFixed;
  37
  38 /**
  39  * Track|Pulse|        Positions
  40  * -------------------------------------------------------------------------
  41  *  1   | 0   | 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75
  42  * -------------------------------------------------------------------------
  43  *  2   | 1   | 1, 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76
  44  * -------------------------------------------------------------------------
  45  *  3   | 2   | 2, 7, 12, 17, 22, 27, 32, 37, 42, 47, 52, 57, 62, 67, 72, 77
  46  * -------------------------------------------------------------------------
  47  *
  48  * Table contains only first the pulse indexes.
  49  *
  50  * Used in G.729 @@8k, G.729 @@4.4k, AMR @@7.95k, AMR @@7.40k
  51  */
  52 extern const uint8_t ff_fc_4pulses_8bits_tracks_13[16];
  53
  54 /**
  55  * Track|Pulse|        Positions
  56  * -------------------------------------------------------------------------
  57  *  4   | 3   | 3, 8, 13, 18, 23, 28, 33, 38, 43, 48, 53, 58, 63, 68, 73, 78
  58  *      |     | 4, 9, 14, 19, 24, 29, 34, 39, 44, 49, 54, 59, 64, 69, 74, 79
  59  * -------------------------------------------------------------------------
  60  *
  61  * @remark Track in the table should be read top-to-bottom, left-to-right.
  62  *
  63  * Used in G.729 @@8k, G.729 @@4.4k, AMR @@7.95k, AMR @@7.40k
  64  */
  65 extern const uint8_t ff_fc_4pulses_8bits_track_4[32];
  66
  67 /**
  68  * Track|Pulse|        Positions
  69  * -----------------------------------------
  70  *  1   | 0   | 1, 6, 11, 16, 21, 26, 31, 36
  71  *      |     | 3, 8, 13, 18, 23, 28, 33, 38
  72  * -----------------------------------------
  73  *
  74  * @remark Track in the table should be read top-to-bottom, left-to-right.
  75  *
  76  * @note (EE) Reference G.729D code also uses gray decoding for each
  77  *            pulse index before looking up the value in the table.
  78  *
  79  * Used in G.729 @@6.4k (with gray coding), AMR @@5.9k (without gray coding)
  80  */
  81 extern const uint8_t ff_fc_2pulses_9bits_track1[16];
  82 extern const uint8_t ff_fc_2pulses_9bits_track1_gray[16];
  83
  84 /**
  85  * b60 hamming windowed sinc function coefficients
  86  */
  87 extern const float ff_b60_sinc[61];
  88
  89 /**
  90  * Table of pow(0.7,n)
  91  */
  92 extern const float ff_pow_0_7[10];
  93
  94 /**
  95  * Table of pow(0.75,n)
  96  */
  97 extern const float ff_pow_0_75[10];
  98
  99 /**
 100  * Table of pow(0.55,n)
 101  */
 102 extern const float ff_pow_0_55[10];
 103
 104 /**
 105  * Decode fixed-codebook vector (3.8 and D.5.8 of G.729, 5.7.1 of AMR).
 106  * @param[out] fc_v decoded fixed codebook vector (2.13)
 107  * @param tab1 table used for first pulse_count pulses
 108  * @param tab2 table used for last pulse
 109  * @param pulse_indexes fixed codebook indexes
 110  * @param pulse_signs signs of the excitation pulses (0 bit value
 111  *                     means negative sign)
 112  * @param bits number of bits per one pulse index
 113  * @param pulse_count number of pulses decoded using first table
 114  * @param bits length of one pulse index in bits
 115  *
 116  * Used in G.729 @@8k, G.729 @@4.4k, G.729 @@6.4k, AMR @@7.95k, AMR @@7.40k
 117  */
 118 void ff_acelp_fc_pulse_per_track(int16_t* fc_v,
 119                                  const uint8_t *tab1,
 120                                  const uint8_t *tab2,
 121                                  int pulse_indexes,
 122                                  int pulse_signs,
 123                                  int pulse_count,
 124                                  int bits);
 125
 126 /**
 127  * Decode the algebraic codebook index to pulse positions and signs and
 128  * construct the algebraic codebook vector for MODE_12k2.
 129  *
 130  * @note: The positions and signs are explicitly coded in MODE_12k2.
 131  *
 132  * @param fixed_index          positions of the ten pulses
 133  * @param fixed_sparse         pointer to the algebraic codebook vector
 134  * @param gray_decode          gray decoding table
 135  * @param half_pulse_count     number of couples of pulses
 136  * @param bits                 length of one pulse index in bits
 137  */
 138 void ff_decode_10_pulses_35bits(const int16_t *fixed_index,
 139                                 AMRFixed *fixed_sparse,
 140                                 const uint8_t *gray_decode,
 141                                 int half_pulse_count, int bits);
 142
 143
 144 /**
 145  * weighted sum of two vectors with rounding.
 146  * @param[out] out result of addition
 147  * @param in_a first vector
 148  * @param in_b second vector
 149  * @param weight_coeff_a first vector weight coefficient
 150  * @param weight_coeff_a second vector weight coefficient
 151  * @param rounder this value will be added to the sum of the two vectors
 152  * @param shift result will be shifted to right by this value
 153  * @param length vectors length
 154  *
 155  * @note It is safe to pass the same buffer for out and in_a or in_b.
 156  *
 157  *  out[i] = (in_a[i]*weight_a + in_b[i]*weight_b + rounder) >> shift
 158  */
 159 void ff_acelp_weighted_vector_sum(int16_t* out,
 160                                   const int16_t *in_a,
 161                                   const int16_t *in_b,
 162                                   int16_t weight_coeff_a,
 163                                   int16_t weight_coeff_b,
 164                                   int16_t rounder,
 165                                   int shift,
 166                                   int length);
 167
 168 /**
 169  * float implementation of weighted sum of two vectors.
 170  * @param[out] out result of addition
 171  * @param in_a first vector
 172  * @param in_b second vector
 173  * @param weight_coeff_a first vector weight coefficient
 174  * @param weight_coeff_a second vector weight coefficient
 175  * @param length vectors length
 176  *
 177  * @note It is safe to pass the same buffer for out and in_a or in_b.
 178  */
 179 void ff_weighted_vector_sumf(float *out, const float *in_a, const float *in_b,
 180                              float weight_coeff_a, float weight_coeff_b,
 181                              int length);
 182
 183 /**
 184  * Adaptive gain control (as used in AMR postfiltering)
 185  *
 186  * @param out output buffer for filtered speech data
 187  * @param in the input speech buffer (may be the same as out)
 188  * @param speech_energ input energy
 189  * @param size the input buffer size
 190  * @param alpha exponential filter factor
 191  * @param gain_mem a pointer to the filter memory (single float of size)
 192  */
 193 void ff_adaptive_gain_control(float *out, const float *in, float speech_energ,
 194                               int size, float alpha, float *gain_mem);
 195
 196 /**
 197  * Set the sum of squares of a signal by scaling
 198  *
 199  * @param out output samples
 200  * @param in input samples
 201  * @param sum_of_squares new sum of squares
 202  * @param n number of samples
 203  *
 204  * @note If the input is zero (or its energy underflows), the output is zero.
 205  *       This is the behavior of AGC in the AMR reference decoder. The QCELP
 206  *       reference decoder seems to have undefined behavior.
 207  *
 208  * TIA/EIA/IS-733 2.4.8.3-2/3/4/5, 2.4.8.6
 209  * 3GPP TS 26.090 6.1 (6)
 210  */
 211 void ff_scale_vector_to_given_sum_of_squares(float *out, const float *in,
 212                                              float sum_of_squares, const int n);
 213
 214 /**
 215  * Add fixed vector to an array from a sparse representation
 216  *
 217  * @param out fixed vector with pitch sharpening
 218  * @param in sparse fixed vector
 219  * @param scale number to multiply the fixed vector by
 220  * @param size the output vector size
 221  */
 222 void ff_set_fixed_vector(float *out, const AMRFixed *in, float scale, int size);
 223
 224 /**
 225  * Clear array values set by set_fixed_vector
 226  *
 227  * @param out fixed vector to be cleared
 228  * @param in sparse fixed vector
 229  * @param size the output vector size
 230  */
 231 void ff_clear_fixed_vector(float *out, const AMRFixed *in, int size);
 232
 233 #endif /* AVCODEC_ACELP_VECTORS_H */