The Tor Browser: media/libopus/silk/tuning

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

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    15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

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    24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

    25 POSSIBILITY OF SUCH DAMAGE.

    26 ***********************************************************************/

    28 #ifndef SILK_TUNING_PARAMETERS_H

    29 #define SILK_TUNING_PARAMETERS_H

    31 #ifdef __cplusplus

    32 extern "C"

    33 {

    34 #endif

    36 /* Decay time for bitreservoir */

    37 #define BITRESERVOIR_DECAY_TIME_MS                      500

    39 /*******************/

    40 /* Pitch estimator */

    41 /*******************/

    43 /* Level of noise floor for whitening filter LPC analysis in pitch analysis */

    44 #define FIND_PITCH_WHITE_NOISE_FRACTION                 1e-3f

    46 /* Bandwidth expansion for whitening filter in pitch analysis */

    47 #define FIND_PITCH_BANDWIDTH_EXPANSION                  0.99f

    49 /*********************/

    50 /* Linear prediction */

    51 /*********************/

    53 /* LPC analysis regularization */

    54 #define FIND_LPC_COND_FAC                               1e-5f

    56 /* LTP analysis defines */

    57 #define FIND_LTP_COND_FAC                               1e-5f

    58 #define LTP_DAMPING                                     0.05f

    59 #define LTP_SMOOTHING                                   0.1f

    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

    66 /* Max cumulative LTP gain */

    67 #define MAX_SUM_LOG_GAIN_DB								250.0f

    69 /***********************/

    70 /* High pass filtering */

    71 /***********************/

    73 /* Smoothing parameters for low end of pitch frequency range estimation */

    74 #define VARIABLE_HP_SMTH_COEF1                          0.1f

    75 #define VARIABLE_HP_SMTH_COEF2                          0.015f

    76 #define VARIABLE_HP_MAX_DELTA_FREQ                      0.4f

    78 /* Min and max cut-off frequency values (-3 dB points) */

    79 #define VARIABLE_HP_MIN_CUTOFF_HZ                       60

    80 #define VARIABLE_HP_MAX_CUTOFF_HZ                       100

    82 /***********/

    83 /* Various */

    84 /***********/

    86 /* VAD threshold */

    87 #define SPEECH_ACTIVITY_DTX_THRES                       0.05f

    89 /* Speech Activity LBRR enable threshold */

    90 #define LBRR_SPEECH_ACTIVITY_THRES                      0.3f

    92 /*************************/

    93 /* Perceptual parameters */

    94 /*************************/

    96 /* reduction in coding SNR during low speech activity */

    97 #define BG_SNR_DECR_dB                                  2.0f

    99 /* factor for reducing quantization noise during voiced speech */

   100 #define HARM_SNR_INCR_dB                                2.0f

   102 /* factor for reducing quantization noise for unvoiced sparse signals */

   103 #define SPARSE_SNR_INCR_dB                              2.0f

   105 /* threshold for sparseness measure above which to use lower quantization offset during unvoiced */

   106 #define SPARSENESS_THRESHOLD_QNT_OFFSET                 0.75f

   108 /* warping control */

   109 #define WARPING_MULTIPLIER                              0.015f

   111 /* fraction added to first autocorrelation value */

   112 #define SHAPE_WHITE_NOISE_FRACTION                      5e-5f

   114 /* noise shaping filter chirp factor */

   115 #define BANDWIDTH_EXPANSION                             0.95f

   117 /* difference between chirp factors for analysis and synthesis noise shaping filters at low bitrates */

   118 #define LOW_RATE_BANDWIDTH_EXPANSION_DELTA              0.01f

   120 /* extra harmonic boosting (signal shaping) at low bitrates */

   121 #define LOW_RATE_HARMONIC_BOOST                         0.1f

   123 /* extra harmonic boosting (signal shaping) for noisy input signals */

   124 #define LOW_INPUT_QUALITY_HARMONIC_BOOST                0.1f

   126 /* harmonic noise shaping */

   127 #define HARMONIC_SHAPING                                0.3f

   129 /* extra harmonic noise shaping for high bitrates or noisy input */

   130 #define HIGH_RATE_OR_LOW_QUALITY_HARMONIC_SHAPING       0.2f

   132 /* parameter for shaping noise towards higher frequencies */

   133 #define HP_NOISE_COEF                                   0.25f

   135 /* parameter for shaping noise even more towards higher frequencies during voiced speech */

   136 #define HARM_HP_NOISE_COEF                              0.35f

   138 /* parameter for applying a high-pass tilt to the input signal */

   139 #define INPUT_TILT                                      0.05f

   141 /* parameter for extra high-pass tilt to the input signal at high rates */

   142 #define HIGH_RATE_INPUT_TILT                            0.1f

   144 /* parameter for reducing noise at the very low frequencies */

   145 #define LOW_FREQ_SHAPING                                4.0f

   147 /* less reduction of noise at the very low frequencies for signals with low SNR at low frequencies */

   148 #define LOW_QUALITY_LOW_FREQ_SHAPING_DECR               0.5f

   150 /* subframe smoothing coefficient for HarmBoost, HarmShapeGain, Tilt (lower -> more smoothing) */

   151 #define SUBFR_SMTH_COEF                                 0.4f

   153 /* parameters defining the R/D tradeoff in the residual quantizer */

   154 #define LAMBDA_OFFSET                                   1.2f

   155 #define LAMBDA_SPEECH_ACT                               -0.2f

   156 #define LAMBDA_DELAYED_DECISIONS                        -0.05f

   157 #define LAMBDA_INPUT_QUALITY                            -0.1f

   158 #define LAMBDA_CODING_QUALITY                           -0.2f

   159 #define LAMBDA_QUANT_OFFSET                             0.8f

   161 /* Compensation in bitrate calculations for 10 ms modes */

   162 #define REDUCE_BITRATE_10_MS_BPS                        2200

   164 /* Maximum time before allowing a bandwidth transition */

   165 #define MAX_BANDWIDTH_SWITCH_DELAY_MS                   5000

   167 #ifdef __cplusplus

   168 }

   169 #endif

   171 #endif /* SILK_TUNING_PARAMETERS_H */

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