ref: e4a74ddeb9788eab84d10660e958fe706619892f
dir: /silk/tuning_parameters.h/
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#ifndef SILK_TUNING_PARAMETERS_H
#define SILK_TUNING_PARAMETERS_H
#ifdef __cplusplus
extern "C"
{
#endif
/* Decay time for bitreservoir */
#define BITRESERVOIR_DECAY_TIME_MS 500
/*******************/
/* Pitch estimator */
/*******************/
/* Level of noise floor for whitening filter LPC analysis in pitch analysis */
#define FIND_PITCH_WHITE_NOISE_FRACTION 1e-3f
/* Bandwidth expansion for whitening filter in pitch analysis */
#define FIND_PITCH_BANDWIDTH_EXPANSION 0.99f
/*********************/
/* Linear prediction */
/*********************/
/* LPC analysis regularization */
#define FIND_LPC_COND_FAC 1e-5f
/* Max cumulative LTP gain */
#define MAX_SUM_LOG_GAIN_DB 250.0f
/* LTP analysis defines */
#define LTP_CORR_INV_MAX 0.03f
/***********************/
/* High pass filtering */
/***********************/
/* Smoothing parameters for low end of pitch frequency range estimation */
#define VARIABLE_HP_SMTH_COEF1 0.1f
#define VARIABLE_HP_SMTH_COEF2 0.015f
#define VARIABLE_HP_MAX_DELTA_FREQ 0.4f
/* Min and max cut-off frequency values (-3 dB points) */
#define VARIABLE_HP_MIN_CUTOFF_HZ 60
#define VARIABLE_HP_MAX_CUTOFF_HZ 100
/***********/
/* Various */
/***********/
/* VAD threshold */
#define SPEECH_ACTIVITY_DTX_THRES 0.05f
/* Speech Activity LBRR enable threshold */
#define LBRR_SPEECH_ACTIVITY_THRES 0.3f
/*************************/
/* Perceptual parameters */
/*************************/
/* reduction in coding SNR during low speech activity */
#define BG_SNR_DECR_dB 2.0f
/* factor for reducing quantization noise during voiced speech */
#define HARM_SNR_INCR_dB 2.0f
/* factor for reducing quantization noise for unvoiced sparse signals */
#define SPARSE_SNR_INCR_dB 2.0f
/* threshold for sparseness measure above which to use lower quantization offset during unvoiced */
#define ENERGY_VARIATION_THRESHOLD_QNT_OFFSET 0.6f
/* warping control */
#define WARPING_MULTIPLIER 0.015f
/* fraction added to first autocorrelation value */
#define SHAPE_WHITE_NOISE_FRACTION 3e-5f
/* noise shaping filter chirp factor */
#define BANDWIDTH_EXPANSION 0.94f
/* harmonic noise shaping */
#define HARMONIC_SHAPING 0.3f
/* extra harmonic noise shaping for high bitrates or noisy input */
#define HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING 0.2f
/* parameter for shaping noise towards higher frequencies */
#define HP_NOISE_COEF 0.25f
/* parameter for shaping noise even more towards higher frequencies during voiced speech */
#define HARM_HP_NOISE_COEF 0.35f
/* parameter for applying a high-pass tilt to the input signal */
#define INPUT_TILT 0.05f
/* parameter for extra high-pass tilt to the input signal at high rates */
#define HIGH_RATE_INPUT_TILT 0.1f
/* parameter for reducing noise at the very low frequencies */
#define LOW_FREQ_SHAPING 4.0f
/* less reduction of noise at the very low frequencies for signals with low SNR at low frequencies */
#define LOW_QUALITY_LOW_FREQ_SHAPING_DECR 0.5f
/* subframe smoothing coefficient for HarmBoost, HarmShapeGain, Tilt (lower -> more smoothing) */
#define SUBFR_SMTH_COEF 0.4f
/* parameters defining the R/D tradeoff in the residual quantizer */
#define LAMBDA_OFFSET 1.2f
#define LAMBDA_SPEECH_ACT -0.2f
#define LAMBDA_DELAYED_DECISIONS -0.05f
#define LAMBDA_INPUT_QUALITY -0.1f
#define LAMBDA_CODING_QUALITY -0.2f
#define LAMBDA_QUANT_OFFSET 0.8f
/* Compensation in bitrate calculations for 10 ms modes */
#define REDUCE_BITRATE_10_MS_BPS 2200
/* Maximum time before allowing a bandwidth transition */
#define MAX_BANDWIDTH_SWITCH_DELAY_MS 5000
#ifdef __cplusplus
}
#endif
#endif /* SILK_TUNING_PARAMETERS_H */