/* Find pitch lags */
internal static void silk_find_pitch_lags(
SilkChannelEncoder psEnc, /* I/O encoder state */
SilkEncoderControl psEncCtrl, /* I/O encoder control */
short[] res, /* O residual */
short[] x, /* I Speech signal */
int x_ptr
)
{
int buf_len, i, scale;
int thrhld_Q13, res_nrg;
int x_buf, x_buf_ptr;
short[] Wsig;
int Wsig_ptr;
int[] auto_corr = new int[SilkConstants.MAX_FIND_PITCH_LPC_ORDER + 1];
short[] rc_Q15 = new short[SilkConstants.MAX_FIND_PITCH_LPC_ORDER];
int[] A_Q24 = new int[SilkConstants.MAX_FIND_PITCH_LPC_ORDER];
short[] A_Q12 = new short[SilkConstants.MAX_FIND_PITCH_LPC_ORDER];
/******************************************/
/* Set up buffer lengths etc based on Fs */
/******************************************/
buf_len = psEnc.la_pitch + psEnc.frame_length + psEnc.ltp_mem_length;
/* Safety check */
Inlines.OpusAssert(buf_len >= psEnc.pitch_LPC_win_length);
x_buf = x_ptr - psEnc.ltp_mem_length;
/*************************************/
/* Estimate LPC AR coefficients */
/*************************************/
/* Calculate windowed signal */
Wsig = new short[psEnc.pitch_LPC_win_length];
/* First LA_LTP samples */
x_buf_ptr = x_buf + buf_len - psEnc.pitch_LPC_win_length;
Wsig_ptr = 0;
ApplySineWindow.silk_apply_sine_window(Wsig, Wsig_ptr, x, x_buf_ptr, 1, psEnc.la_pitch);
/* Middle un - windowed samples */
Wsig_ptr += psEnc.la_pitch;
x_buf_ptr += psEnc.la_pitch;
Array.Copy(x, x_buf_ptr, Wsig, Wsig_ptr, (psEnc.pitch_LPC_win_length - Inlines.silk_LSHIFT(psEnc.la_pitch, 1)));
/* Last LA_LTP samples */
Wsig_ptr += psEnc.pitch_LPC_win_length - Inlines.silk_LSHIFT(psEnc.la_pitch, 1);
x_buf_ptr += psEnc.pitch_LPC_win_length - Inlines.silk_LSHIFT(psEnc.la_pitch, 1);
ApplySineWindow.silk_apply_sine_window(Wsig, Wsig_ptr, x, x_buf_ptr, 2, psEnc.la_pitch);
/* Calculate autocorrelation sequence */
BoxedValueInt boxed_scale = new BoxedValueInt();
Autocorrelation.silk_autocorr(auto_corr, boxed_scale, Wsig, psEnc.pitch_LPC_win_length, psEnc.pitchEstimationLPCOrder + 1);
scale = boxed_scale.Val;
/* Add white noise, as fraction of energy */
auto_corr[0] = Inlines.silk_SMLAWB(auto_corr[0], auto_corr[0], ((int)((TuningParameters.FIND_PITCH_WHITE_NOISE_FRACTION) * ((long)1 << (16)) + 0.5)) /*Inlines.SILK_CONST(TuningParameters.FIND_PITCH_WHITE_NOISE_FRACTION, 16)*/) + 1;
/* Calculate the reflection coefficients using schur */
res_nrg = Schur.silk_schur(rc_Q15, auto_corr, psEnc.pitchEstimationLPCOrder);
/* Prediction gain */
psEncCtrl.predGain_Q16 = Inlines.silk_DIV32_varQ(auto_corr[0], Inlines.silk_max_int(res_nrg, 1), 16);
/* Convert reflection coefficients to prediction coefficients */
K2A.silk_k2a(A_Q24, rc_Q15, psEnc.pitchEstimationLPCOrder);
/* Convert From 32 bit Q24 to 16 bit Q12 coefs */
for (i = 0; i < psEnc.pitchEstimationLPCOrder; i++)
{
A_Q12[i] = (short)Inlines.silk_SAT16(Inlines.silk_RSHIFT(A_Q24[i], 12));
}
/* Do BWE */
BWExpander.silk_bwexpander(A_Q12, psEnc.pitchEstimationLPCOrder, ((int)((TuningParameters.FIND_PITCH_BANDWIDTH_EXPANSION) * ((long)1 << (16)) + 0.5)) /*Inlines.SILK_CONST(TuningParameters.FIND_PITCH_BANDWIDTH_EXPANSION, 16)*/);
/*****************************************/
/* LPC analysis filtering */
/*****************************************/
Filters.silk_LPC_analysis_filter(res, 0, x, x_buf, A_Q12, 0, buf_len, psEnc.pitchEstimationLPCOrder);
if (psEnc.indices.signalType != SilkConstants.TYPE_NO_VOICE_ACTIVITY && psEnc.first_frame_after_reset == 0)
{
/* Threshold for pitch estimator */
thrhld_Q13 = ((int)((0.6f) * ((long)1 << (13)) + 0.5)) /*Inlines.SILK_CONST(0.6f, 13)*/;
thrhld_Q13 = Inlines.silk_SMLABB(thrhld_Q13, ((int)((-0.004f) * ((long)1 << (13)) + 0.5)) /*Inlines.SILK_CONST(-0.004f, 13)*/, psEnc.pitchEstimationLPCOrder);
thrhld_Q13 = Inlines.silk_SMLAWB(thrhld_Q13, ((int)((-0.1f) * ((long)1 << (21)) + 0.5)) /*Inlines.SILK_CONST(-0.1f, 21)*/, psEnc.speech_activity_Q8);
thrhld_Q13 = Inlines.silk_SMLABB(thrhld_Q13, ((int)((-0.15f) * ((long)1 << (13)) + 0.5)) /*Inlines.SILK_CONST(-0.15f, 13)*/, Inlines.silk_RSHIFT(psEnc.prevSignalType, 1));
thrhld_Q13 = Inlines.silk_SMLAWB(thrhld_Q13, ((int)((-0.1f) * ((long)1 << (14)) + 0.5)) /*Inlines.SILK_CONST(-0.1f, 14)*/, psEnc.input_tilt_Q15);
thrhld_Q13 = Inlines.silk_SAT16(thrhld_Q13);
/*****************************************/
/* Call pitch estimator */
/*****************************************/
BoxedValueShort boxed_lagIndex = new BoxedValueShort(psEnc.indices.lagIndex);
BoxedValueSbyte boxed_contourIndex = new BoxedValueSbyte(psEnc.indices.contourIndex);
BoxedValueInt boxed_LTPcorr = new BoxedValueInt(psEnc.LTPCorr_Q15);
if (PitchAnalysisCore.silk_pitch_analysis_core(res, psEncCtrl.pitchL, boxed_lagIndex, boxed_contourIndex,
boxed_LTPcorr, psEnc.prevLag, psEnc.pitchEstimationThreshold_Q16,
(int)thrhld_Q13, psEnc.fs_kHz, psEnc.pitchEstimationComplexity, psEnc.nb_subfr) == 0)
{
psEnc.indices.signalType = SilkConstants.TYPE_VOICED;
}
else
{
psEnc.indices.signalType = SilkConstants.TYPE_UNVOICED;
}
psEnc.indices.lagIndex = boxed_lagIndex.Val;
psEnc.indices.contourIndex = boxed_contourIndex.Val;
psEnc.LTPCorr_Q15 = boxed_LTPcorr.Val;
}
else
{
Arrays.MemSetInt(psEncCtrl.pitchL, 0, SilkConstants.MAX_NB_SUBFR);
psEnc.indices.lagIndex = 0;
psEnc.indices.contourIndex = 0;
psEnc.LTPCorr_Q15 = 0;
}
}