Chris@69: /***********************************************************************
Chris@69: Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Chris@69: Redistribution and use in source and binary forms, with or without
Chris@69: modification, are permitted provided that the following conditions
Chris@69: are met:
Chris@69: - Redistributions of source code must retain the above copyright notice,
Chris@69: this list of conditions and the following disclaimer.
Chris@69: - Redistributions in binary form must reproduce the above copyright
Chris@69: notice, this list of conditions and the following disclaimer in the
Chris@69: documentation and/or other materials provided with the distribution.
Chris@69: - Neither the name of Internet Society, IETF or IETF Trust, nor the
Chris@69: names of specific contributors, may be used to endorse or promote
Chris@69: products derived from this software without specific prior written
Chris@69: permission.
Chris@69: THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
Chris@69: AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
Chris@69: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
Chris@69: ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
Chris@69: LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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Chris@69: INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
Chris@69: CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
Chris@69: ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
Chris@69: POSSIBILITY OF SUCH DAMAGE.
Chris@69: ***********************************************************************/
Chris@69: 
Chris@69: #ifndef SILK_TUNING_PARAMETERS_H
Chris@69: #define SILK_TUNING_PARAMETERS_H
Chris@69: 
Chris@69: #ifdef __cplusplus
Chris@69: extern "C"
Chris@69: {
Chris@69: #endif
Chris@69: 
Chris@69: /* Decay time for bitreservoir */
Chris@69: #define BITRESERVOIR_DECAY_TIME_MS                      500
Chris@69: 
Chris@69: /*******************/
Chris@69: /* Pitch estimator */
Chris@69: /*******************/
Chris@69: 
Chris@69: /* Level of noise floor for whitening filter LPC analysis in pitch analysis */
Chris@69: #define FIND_PITCH_WHITE_NOISE_FRACTION                 1e-3f
Chris@69: 
Chris@69: /* Bandwidth expansion for whitening filter in pitch analysis */
Chris@69: #define FIND_PITCH_BANDWIDTH_EXPANSION                  0.99f
Chris@69: 
Chris@69: /*********************/
Chris@69: /* Linear prediction */
Chris@69: /*********************/
Chris@69: 
Chris@69: /* LPC analysis regularization */
Chris@69: #define FIND_LPC_COND_FAC                               1e-5f
Chris@69: 
Chris@69: /* Max cumulative LTP gain */
Chris@69: #define MAX_SUM_LOG_GAIN_DB                             250.0f
Chris@69: 
Chris@69: /* LTP analysis defines */
Chris@69: #define LTP_CORR_INV_MAX                                0.03f
Chris@69: 
Chris@69: /***********************/
Chris@69: /* High pass filtering */
Chris@69: /***********************/
Chris@69: 
Chris@69: /* Smoothing parameters for low end of pitch frequency range estimation */
Chris@69: #define VARIABLE_HP_SMTH_COEF1                          0.1f
Chris@69: #define VARIABLE_HP_SMTH_COEF2                          0.015f
Chris@69: #define VARIABLE_HP_MAX_DELTA_FREQ                      0.4f
Chris@69: 
Chris@69: /* Min and max cut-off frequency values (-3 dB points) */
Chris@69: #define VARIABLE_HP_MIN_CUTOFF_HZ                       60
Chris@69: #define VARIABLE_HP_MAX_CUTOFF_HZ                       100
Chris@69: 
Chris@69: /***********/
Chris@69: /* Various */
Chris@69: /***********/
Chris@69: 
Chris@69: /* VAD threshold */
Chris@69: #define SPEECH_ACTIVITY_DTX_THRES                       0.05f
Chris@69: 
Chris@69: /* Speech Activity LBRR enable threshold */
Chris@69: #define LBRR_SPEECH_ACTIVITY_THRES                      0.3f
Chris@69: 
Chris@69: /*************************/
Chris@69: /* Perceptual parameters */
Chris@69: /*************************/
Chris@69: 
Chris@69: /* reduction in coding SNR during low speech activity */
Chris@69: #define BG_SNR_DECR_dB                                  2.0f
Chris@69: 
Chris@69: /* factor for reducing quantization noise during voiced speech */
Chris@69: #define HARM_SNR_INCR_dB                                2.0f
Chris@69: 
Chris@69: /* factor for reducing quantization noise for unvoiced sparse signals */
Chris@69: #define SPARSE_SNR_INCR_dB                              2.0f
Chris@69: 
Chris@69: /* threshold for sparseness measure above which to use lower quantization offset during unvoiced */
Chris@69: #define ENERGY_VARIATION_THRESHOLD_QNT_OFFSET           0.6f
Chris@69: 
Chris@69: /* warping control */
Chris@69: #define WARPING_MULTIPLIER                              0.015f
Chris@69: 
Chris@69: /* fraction added to first autocorrelation value */
Chris@69: #define SHAPE_WHITE_NOISE_FRACTION                      3e-5f
Chris@69: 
Chris@69: /* noise shaping filter chirp factor */
Chris@69: #define BANDWIDTH_EXPANSION                             0.94f
Chris@69: 
Chris@69: /* harmonic noise shaping */
Chris@69: #define HARMONIC_SHAPING                                0.3f
Chris@69: 
Chris@69: /* extra harmonic noise shaping for high bitrates or noisy input */
Chris@69: #define HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING       0.2f
Chris@69: 
Chris@69: /* parameter for shaping noise towards higher frequencies */
Chris@69: #define HP_NOISE_COEF                                   0.25f
Chris@69: 
Chris@69: /* parameter for shaping noise even more towards higher frequencies during voiced speech */
Chris@69: #define HARM_HP_NOISE_COEF                              0.35f
Chris@69: 
Chris@69: /* parameter for applying a high-pass tilt to the input signal */
Chris@69: #define INPUT_TILT                                      0.05f
Chris@69: 
Chris@69: /* parameter for extra high-pass tilt to the input signal at high rates */
Chris@69: #define HIGH_RATE_INPUT_TILT                            0.1f
Chris@69: 
Chris@69: /* parameter for reducing noise at the very low frequencies */
Chris@69: #define LOW_FREQ_SHAPING                                4.0f
Chris@69: 
Chris@69: /* less reduction of noise at the very low frequencies for signals with low SNR at low frequencies */
Chris@69: #define LOW_QUALITY_LOW_FREQ_SHAPING_DECR               0.5f
Chris@69: 
Chris@69: /* subframe smoothing coefficient for HarmBoost, HarmShapeGain, Tilt (lower -> more smoothing) */
Chris@69: #define SUBFR_SMTH_COEF                                 0.4f
Chris@69: 
Chris@69: /* parameters defining the R/D tradeoff in the residual quantizer */
Chris@69: #define LAMBDA_OFFSET                                   1.2f
Chris@69: #define LAMBDA_SPEECH_ACT                               -0.2f
Chris@69: #define LAMBDA_DELAYED_DECISIONS                        -0.05f
Chris@69: #define LAMBDA_INPUT_QUALITY                            -0.1f
Chris@69: #define LAMBDA_CODING_QUALITY                           -0.2f
Chris@69: #define LAMBDA_QUANT_OFFSET                             0.8f
Chris@69: 
Chris@69: /* Compensation in bitrate calculations for 10 ms modes */
Chris@69: #define REDUCE_BITRATE_10_MS_BPS                        2200
Chris@69: 
Chris@69: /* Maximum time before allowing a bandwidth transition */
Chris@69: #define MAX_BANDWIDTH_SWITCH_DELAY_MS                   5000
Chris@69: 
Chris@69: #ifdef __cplusplus
Chris@69: }
Chris@69: #endif
Chris@69: 
Chris@69: #endif /* SILK_TUNING_PARAMETERS_H */