Smart Remote 3 nRF52 v1.2
tuning_parameters.h
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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 regularization */
54 #define FIND_LPC_COND_FAC 1e-5f
55 
56 /* Max cumulative LTP gain */
57 #define MAX_SUM_LOG_GAIN_DB 250.0f
58 
59 /* LTP analysis defines */
60 #define LTP_CORR_INV_MAX 0.03f
61 
62 /***********************/
63 /* High pass filtering */
64 /***********************/
65 
66 /* Smoothing parameters for low end of pitch frequency range estimation */
67 #define VARIABLE_HP_SMTH_COEF1 0.1f
68 #define VARIABLE_HP_SMTH_COEF2 0.015f
69 #define VARIABLE_HP_MAX_DELTA_FREQ 0.4f
70 
71 /* Min and max cut-off frequency values (-3 dB points) */
72 #define VARIABLE_HP_MIN_CUTOFF_HZ 60
73 #define VARIABLE_HP_MAX_CUTOFF_HZ 100
74 
75 /***********/
76 /* Various */
77 /***********/
78 
79 /* VAD threshold */
80 #define SPEECH_ACTIVITY_DTX_THRES 0.05f
81 
82 /* Speech Activity LBRR enable threshold */
83 #define LBRR_SPEECH_ACTIVITY_THRES 0.3f
84 
85 /*************************/
86 /* Perceptual parameters */
87 /*************************/
88 
89 /* reduction in coding SNR during low speech activity */
90 #define BG_SNR_DECR_dB 2.0f
91 
92 /* factor for reducing quantization noise during voiced speech */
93 #define HARM_SNR_INCR_dB 2.0f
94 
95 /* factor for reducing quantization noise for unvoiced sparse signals */
96 #define SPARSE_SNR_INCR_dB 2.0f
97 
98 /* threshold for sparseness measure above which to use lower quantization offset during unvoiced */
99 #define ENERGY_VARIATION_THRESHOLD_QNT_OFFSET 0.6f
100 
101 /* warping control */
102 #define WARPING_MULTIPLIER 0.015f
103 
104 /* fraction added to first autocorrelation value */
105 #define SHAPE_WHITE_NOISE_FRACTION 3e-5f
106 
107 /* noise shaping filter chirp factor */
108 #define BANDWIDTH_EXPANSION 0.94f
109 
110 /* harmonic noise shaping */
111 #define HARMONIC_SHAPING 0.3f
112 
113 /* extra harmonic noise shaping for high bitrates or noisy input */
114 #define HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING 0.2f
115 
116 /* parameter for shaping noise towards higher frequencies */
117 #define HP_NOISE_COEF 0.25f
118 
119 /* parameter for shaping noise even more towards higher frequencies during voiced speech */
120 #define HARM_HP_NOISE_COEF 0.35f
121 
122 /* parameter for applying a high-pass tilt to the input signal */
123 #define INPUT_TILT 0.05f
124 
125 /* parameter for extra high-pass tilt to the input signal at high rates */
126 #define HIGH_RATE_INPUT_TILT 0.1f
127 
128 /* parameter for reducing noise at the very low frequencies */
129 #define LOW_FREQ_SHAPING 4.0f
130 
131 /* less reduction of noise at the very low frequencies for signals with low SNR at low frequencies */
132 #define LOW_QUALITY_LOW_FREQ_SHAPING_DECR 0.5f
133 
134 /* subframe smoothing coefficient for HarmBoost, HarmShapeGain, Tilt (lower -> more smoothing) */
135 #define SUBFR_SMTH_COEF 0.4f
136 
137 /* parameters defining the R/D tradeoff in the residual quantizer */
138 #define LAMBDA_OFFSET 1.2f
139 #define LAMBDA_SPEECH_ACT -0.2f
140 #define LAMBDA_DELAYED_DECISIONS -0.05f
141 #define LAMBDA_INPUT_QUALITY -0.1f
142 #define LAMBDA_CODING_QUALITY -0.2f
143 #define LAMBDA_QUANT_OFFSET 0.8f
144 
145 /* Compensation in bitrate calculations for 10 ms modes */
146 #define REDUCE_BITRATE_10_MS_BPS 2200
147 
148 /* Maximum time before allowing a bandwidth transition */
149 #define MAX_BANDWIDTH_SWITCH_DELAY_MS 5000
150 
151 #ifdef __cplusplus
152 }
153 #endif
154 
155 #endif /* SILK_TUNING_PARAMETERS_H */
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