1 /*********************************************************************** 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved. 3 Redistribution and use in source and binary forms, with or without 4 modification, are permitted provided that the following conditions 5 are met: 6 - Redistributions of source code must retain the above copyright notice, 7 this list of conditions and the following disclaimer. 8 - Redistributions in binary form must reproduce the above copyright 9 notice, this list of conditions and the following disclaimer in the 10 documentation and/or other materials provided with the distribution. 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the 12 names of specific contributors, may be used to endorse or promote 13 products derived from this software without specific prior written 14 permission. 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 POSSIBILITY OF SUCH DAMAGE. 26 ***********************************************************************/ 27 28 #ifndef SILK_TUNING_PARAMETERS_H 29 #define SILK_TUNING_PARAMETERS_H 30 31 #ifdef __cplusplus 32 extern "C" 33 { 34 #endif 35 36 /* Decay time for bitreservoir */ 37 #define BITRESERVOIR_DECAY_TIME_MS 500 38 39 /*******************/ 40 /* Pitch estimator */ 41 /*******************/ 42 43 /* Level of noise floor for whitening filter LPC analysis in pitch analysis */ 44 #define FIND_PITCH_WHITE_NOISE_FRACTION 1e-3f 45 46 /* Bandwidth expansion for whitening filter in pitch analysis */ 47 #define FIND_PITCH_BANDWIDTH_EXPANSION 0.99f 48 49 /*********************/ 50 /* Linear prediction */ 51 /*********************/ 52 53 /* LPC analysis defines: regularization and bandwidth expansion */ 54 #define FIND_LPC_COND_FAC 1e-5f 55 56 /* LTP analysis defines */ 57 #define FIND_LTP_COND_FAC 1e-5f 58 #define LTP_DAMPING 0.05f 59 #define LTP_SMOOTHING 0.1f 60 61 /* LTP quantization settings */ 62 #define MU_LTP_QUANT_NB 0.03f 63 #define MU_LTP_QUANT_MB 0.025f 64 #define MU_LTP_QUANT_WB 0.02f 65 66 /***********************/ 67 /* High pass filtering */ 68 /***********************/ 69 70 /* Smoothing parameters for low end of pitch frequency range estimation */ 71 #define VARIABLE_HP_SMTH_COEF1 0.1f 72 #define VARIABLE_HP_SMTH_COEF2 0.015f 73 #define VARIABLE_HP_MAX_DELTA_FREQ 0.4f 74 75 /* Min and max cut-off frequency values (-3 dB points) */ 76 #define VARIABLE_HP_MIN_CUTOFF_HZ 60 77 #define VARIABLE_HP_MAX_CUTOFF_HZ 100 78 79 /***********/ 80 /* Various */ 81 /***********/ 82 83 /* VAD threshold */ 84 #define SPEECH_ACTIVITY_DTX_THRES 0.05f 85 86 /* Speech Activity LBRR enable threshold */ 87 #define LBRR_SPEECH_ACTIVITY_THRES 0.3f 88 89 /*************************/ 90 /* Perceptual parameters */ 91 /*************************/ 92 93 /* reduction in coding SNR during low speech activity */ 94 #define BG_SNR_DECR_dB 2.0f 95 96 /* factor for reducing quantization noise during voiced speech */ 97 #define HARM_SNR_INCR_dB 2.0f 98 99 /* factor for reducing quantization noise for unvoiced sparse signals */ 100 #define SPARSE_SNR_INCR_dB 2.0f 101 102 /* threshold for sparseness measure above which to use lower quantization offset during unvoiced */ 103 #define SPARSENESS_THRESHOLD_QNT_OFFSET 0.75f 104 105 /* warping control */ 106 #define WARPING_MULTIPLIER 0.015f 107 108 /* fraction added to first autocorrelation value */ 109 #define SHAPE_WHITE_NOISE_FRACTION 5e-5f 110 111 /* noise shaping filter chirp factor */ 112 #define BANDWIDTH_EXPANSION 0.95f 113 114 /* difference between chirp factors for analysis and synthesis noise shaping filters at low bitrates */ 115 #define LOW_RATE_BANDWIDTH_EXPANSION_DELTA 0.01f 116 117 /* extra harmonic boosting (signal shaping) at low bitrates */ 118 #define LOW_RATE_HARMONIC_BOOST 0.1f 119 120 /* extra harmonic boosting (signal shaping) for noisy input signals */ 121 #define LOW_INPUT_QUALITY_HARMONIC_BOOST 0.1f 122 123 /* harmonic noise shaping */ 124 #define HARMONIC_SHAPING 0.3f 125 126 /* extra harmonic noise shaping for high bitrates or noisy input */ 127 #define HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING 0.2f 128 129 /* parameter for shaping noise towards higher frequencies */ 130 #define HP_NOISE_COEF 0.25f 131 132 /* parameter for shaping noise even more towards higher frequencies during voiced speech */ 133 #define HARM_HP_NOISE_COEF 0.35f 134 135 /* parameter for applying a high-pass tilt to the input signal */ 136 #define INPUT_TILT 0.05f 137 138 /* parameter for extra high-pass tilt to the input signal at high rates */ 139 #define HIGH_RATE_INPUT_TILT 0.1f 140 141 /* parameter for reducing noise at the very low frequencies */ 142 #define LOW_FREQ_SHAPING 4.0f 143 144 /* less reduction of noise at the very low frequencies for signals with low SNR at low frequencies */ 145 #define LOW_QUALITY_LOW_FREQ_SHAPING_DECR 0.5f 146 147 /* subframe smoothing coefficient for HarmBoost, HarmShapeGain, Tilt (lower -> more smoothing) */ 148 #define SUBFR_SMTH_COEF 0.4f 149 150 /* parameters defining the R/D tradeoff in the residual quantizer */ 151 #define LAMBDA_OFFSET 1.2f 152 #define LAMBDA_SPEECH_ACT -0.2f 153 #define LAMBDA_DELAYED_DECISIONS -0.05f 154 #define LAMBDA_INPUT_QUALITY -0.1f 155 #define LAMBDA_CODING_QUALITY -0.2f 156 #define LAMBDA_QUANT_OFFSET 0.8f 157 158 /* Compensation in bitrate calculations for 10 ms modes */ 159 #define REDUCE_BITRATE_10_MS_BPS 2200 160 161 /* Maximum time before allowing a bandwidth transition */ 162 #define MAX_BANDWIDTH_SWITCH_DELAY_MS 5000 163 164 #ifdef __cplusplus 165 } 166 #endif 167 168 #endif /* SILK_TUNING_PARAMETERS_H */ 169
