/* uses SMLAWB(), requiring armv5E and higher. */
SKP_int32 SKP_Silk_schur( /* O: Returns residual energy */
SKP_int16 *rc_Q15, /* O: reflection coefficients [order] Q15 */
const SKP_int32 *c, /* I: correlations [order+1] */
const SKP_int32 order /* I: prediction order */
)
{
SKP_int k, n, lz;
SKP_int32 C[ SKP_Silk_MAX_ORDER_LPC + 1 ][ 2 ];
SKP_int32 Ctmp1, Ctmp2, rc_tmp_Q15;
/* Get number of leading zeros */
lz = SKP_Silk_CLZ32( c[ 0 ] );
/* Copy correlations and adjust level to Q30 */
if( lz < 2 ) {
/* lz must be 1, so shift one to the right */
for( k = 0; k < order + 1; k++ ) {
C[ k ][ 0 ] = C[ k ][ 1 ] = SKP_RSHIFT( c[ k ], 1 );
}
} else if( lz > 2 ) {
/* Shift to the left */
lz -= 2;
for( k = 0; k < order + 1; k++ ) {
C[ k ][ 0 ] = C[ k ][ 1 ] = SKP_LSHIFT( c[k], lz );
}
} else {
/* No need to shift */
for( k = 0; k < order + 1; k++ ) {
C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
}
}
for( k = 0; k < order; k++ ) {
/* Get reflection coefficient */
rc_tmp_Q15 = -SKP_DIV32_16( C[ k + 1 ][ 0 ], SKP_max_32( SKP_RSHIFT( C[ 0 ][ 1 ], 15 ), 1 ) );
/* Clip (shouldn't happen for properly conditioned inputs) */
rc_tmp_Q15 = SKP_SAT16( rc_tmp_Q15 );
/* Store */
rc_Q15[ k ] = (SKP_int16)rc_tmp_Q15;
/* Update correlations */
for( n = 0; n < order - k; n++ ) {
Ctmp1 = C[ n + k + 1 ][ 0 ];
Ctmp2 = C[ n ][ 1 ];
C[ n + k + 1 ][ 0 ] = SKP_SMLAWB( Ctmp1, SKP_LSHIFT( Ctmp2, 1 ), rc_tmp_Q15 );
C[ n ][ 1 ] = SKP_SMLAWB( Ctmp2, SKP_LSHIFT( Ctmp1, 1 ), rc_tmp_Q15 );
}
}
/* return residual energy */
return C[0][1];
}
/* Helper function, interpolates the filter taps */
SKP_INLINE void silk_LP_interpolate_filter_taps(
SKP_int32 B_Q28[ TRANSITION_NB ],
SKP_int32 A_Q28[ TRANSITION_NA ],
const SKP_int ind,
const SKP_int32 fac_Q16
)
{
SKP_int nb, na;
if( ind < TRANSITION_INT_NUM - 1 ) {
if( fac_Q16 > 0 ) {
if( fac_Q16 < 32768 ) { /* fac_Q16 is in range of a 16-bit int */
/* Piece-wise linear interpolation of B and A */
for( nb = 0; nb < TRANSITION_NB; nb++ ) {
B_Q28[ nb ] = SKP_SMLAWB(
silk_Transition_LP_B_Q28[ ind ][ nb ],
silk_Transition_LP_B_Q28[ ind + 1 ][ nb ] -
silk_Transition_LP_B_Q28[ ind ][ nb ],
fac_Q16 );
}
for( na = 0; na < TRANSITION_NA; na++ ) {
A_Q28[ na ] = SKP_SMLAWB(
silk_Transition_LP_A_Q28[ ind ][ na ],
silk_Transition_LP_A_Q28[ ind + 1 ][ na ] -
silk_Transition_LP_A_Q28[ ind ][ na ],
fac_Q16 );
}
} else { /* ( fac_Q16 - ( 1 << 16 ) ) is in range of a 16-bit int */
SKP_assert( fac_Q16 - ( 1 << 16 ) == SKP_SAT16( fac_Q16 - ( 1 << 16 ) ) );
/* Piece-wise linear interpolation of B and A */
for( nb = 0; nb < TRANSITION_NB; nb++ ) {
B_Q28[ nb ] = SKP_SMLAWB(
silk_Transition_LP_B_Q28[ ind + 1 ][ nb ],
silk_Transition_LP_B_Q28[ ind + 1 ][ nb ] -
silk_Transition_LP_B_Q28[ ind ][ nb ],
fac_Q16 - ( 1 << 16 ) );
}
for( na = 0; na < TRANSITION_NA; na++ ) {
A_Q28[ na ] = SKP_SMLAWB(
silk_Transition_LP_A_Q28[ ind + 1 ][ na ],
silk_Transition_LP_A_Q28[ ind + 1 ][ na ] -
silk_Transition_LP_A_Q28[ ind ][ na ],
fac_Q16 - ( 1 << 16 ) );
}
}
} else {
SKP_memcpy( B_Q28, silk_Transition_LP_B_Q28[ ind ], TRANSITION_NB * sizeof( SKP_int32 ) );
SKP_memcpy( A_Q28, silk_Transition_LP_A_Q28[ ind ], TRANSITION_NA * sizeof( SKP_int32 ) );
}
} else {
SKP_memcpy( B_Q28, silk_Transition_LP_B_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NB * sizeof( SKP_int32 ) );
SKP_memcpy( A_Q28, silk_Transition_LP_A_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NA * sizeof( SKP_int32 ) );
}
}
/* Downsample by a factor 3, low quality */
void SKP_Silk_resampler_down3(
SKP_int32 *S, /* I/O: State vector [ 8 ] */
SKP_int16 *out, /* O: Output signal [ floor(inLen/3) ] */
const SKP_int16 *in, /* I: Input signal [ inLen ] */
SKP_int32 inLen /* I: Number of input samples */
)
{
SKP_int32 nSamplesIn, counter, res_Q6;
SKP_int32 buf[ RESAMPLER_MAX_BATCH_SIZE_IN + ORDER_FIR ];
SKP_int32 *buf_ptr;
/* Copy buffered samples to start of buffer */
SKP_memcpy( buf, S, ORDER_FIR * sizeof( SKP_int32 ) );
/* Iterate over blocks of frameSizeIn input samples */
while( 1 ) {
nSamplesIn = SKP_min( inLen, RESAMPLER_MAX_BATCH_SIZE_IN );
/* Second-order AR filter (output in Q8) */
SKP_Silk_resampler_private_AR2( &S[ ORDER_FIR ], &buf[ ORDER_FIR ], in,
SKP_Silk_Resampler_1_3_COEFS_LQ, nSamplesIn );
/* Interpolate filtered signal */
buf_ptr = buf;
counter = nSamplesIn;
while( counter > 2 ) {
/* Inner product */
res_Q6 = SKP_SMULWB( SKP_ADD32( buf_ptr[ 0 ], buf_ptr[ 5 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 2 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 1 ], buf_ptr[ 4 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 3 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 2 ], buf_ptr[ 3 ] ), SKP_Silk_Resampler_1_3_COEFS_LQ[ 4 ] );
/* Scale down, saturate and store in output array */
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
buf_ptr += 3;
counter -= 3;
}
in += nSamplesIn;
inLen -= nSamplesIn;
if( inLen > 0 ) {
/* More iterations to do; copy last part of filtered signal to beginning of buffer */
SKP_memcpy( buf, &buf[ nSamplesIn ], ORDER_FIR * sizeof( SKP_int32 ) );
} else {
break;
}
}
/* Copy last part of filtered signal to the state for the next call */
SKP_memcpy( S, &buf[ nSamplesIn ], ORDER_FIR * sizeof( SKP_int32 ) );
}
/* Autocorrelations for a warped frequency axis */
void silk_warped_autocorrelation_FIX(
opus_int32 *corr, /* O Result [order + 1] */
opus_int *scale, /* O Scaling of the correlation vector */
const opus_int16 *input, /* I Input data to correlate */
const opus_int warping_Q16, /* I Warping coefficient */
const opus_int length, /* I Length of input */
const opus_int order /* I Correlation order (even) */
)
{
opus_int n, i, lsh;
opus_int32 tmp1_QS, tmp2_QS;
opus_int32 state_QS[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0 };
opus_int64 corr_QC[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0 };
/* Order must be even */
SKP_assert( ( order & 1 ) == 0 );
SKP_assert( 2 * QS - QC >= 0 );
/* Loop over samples */
for( n = 0; n < length; n++ ) {
tmp1_QS = SKP_LSHIFT32( ( opus_int32 )input[ n ], QS );
/* Loop over allpass sections */
for( i = 0; i < order; i += 2 ) {
/* Output of allpass section */
tmp2_QS = SKP_SMLAWB( state_QS[ i ], state_QS[ i + 1 ] - tmp1_QS, warping_Q16 );
state_QS[ i ] = tmp1_QS;
corr_QC[ i ] += SKP_RSHIFT64( SKP_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
/* Output of allpass section */
tmp1_QS = SKP_SMLAWB( state_QS[ i + 1 ], state_QS[ i + 2 ] - tmp2_QS, warping_Q16 );
state_QS[ i + 1 ] = tmp2_QS;
corr_QC[ i + 1 ] += SKP_RSHIFT64( SKP_SMULL( tmp2_QS, state_QS[ 0 ] ), 2 * QS - QC );
}
state_QS[ order ] = tmp1_QS;
corr_QC[ order ] += SKP_RSHIFT64( SKP_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
}
lsh = silk_CLZ64( corr_QC[ 0 ] ) - 35;
lsh = SKP_LIMIT( lsh, -12 - QC, 30 - QC );
*scale = -( QC + lsh );
SKP_assert( *scale >= -30 && *scale <= 12 );
if( lsh >= 0 ) {
for( i = 0; i < order + 1; i++ ) {
corr[ i ] = ( opus_int32 )SKP_CHECK_FIT32( SKP_LSHIFT64( corr_QC[ i ], lsh ) );
}
} else {
for( i = 0; i < order + 1; i++ ) {
corr[ i ] = ( opus_int32 )SKP_CHECK_FIT32( SKP_RSHIFT64( corr_QC[ i ], -lsh ) );
}
}
SKP_assert( corr_QC[ 0 ] >= 0 ); // If breaking, decrease QC
}
/* Convert adaptive Mid/Side representation to Left/Right stereo signal */
void silk_stereo_MS_to_LR(
stereo_dec_state *state, /* I/O State */
opus_int16 x1[], /* I/O Left input signal, becomes mid signal */
opus_int16 x2[], /* I/O Right input signal, becomes side signal */
const opus_int32 pred_Q13[], /* I Predictors */
opus_int fs_kHz, /* I Samples rate (kHz) */
opus_int frame_length /* I Number of samples */
)
{
opus_int n, denom_Q16, delta0_Q13, delta1_Q13;
opus_int32 sum, diff, pred0_Q13, pred1_Q13;
/* Buffering */
SKP_memcpy( x1, state->sMid, 2 * sizeof( opus_int16 ) );
SKP_memcpy( x2, state->sSide, 2 * sizeof( opus_int16 ) );
SKP_memcpy( state->sMid, &x1[ frame_length ], 2 * sizeof( opus_int16 ) );
SKP_memcpy( state->sSide, &x2[ frame_length ], 2 * sizeof( opus_int16 ) );
/* Interpolate predictors and add prediction to side channel */
pred0_Q13 = state->pred_prev_Q13[ 0 ];
pred1_Q13 = state->pred_prev_Q13[ 1 ];
denom_Q16 = SKP_DIV32_16( 1 << 16, STEREO_INTERP_LEN_MS * fs_kHz );
delta0_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 0 ] - state->pred_prev_Q13[ 0 ], denom_Q16 ), 16 );
delta1_Q13 = SKP_RSHIFT_ROUND( SKP_SMULBB( pred_Q13[ 1 ] - state->pred_prev_Q13[ 1 ], denom_Q16 ), 16 );
for( n = 0; n < STEREO_INTERP_LEN_MS * fs_kHz; n++ ) {
pred0_Q13 += delta0_Q13;
pred1_Q13 += delta1_Q13;
sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
}
pred0_Q13 = pred_Q13[ 0 ];
pred1_Q13 = pred_Q13[ 1 ];
for( n = STEREO_INTERP_LEN_MS * fs_kHz; n < frame_length; n++ ) {
sum = SKP_LSHIFT( SKP_ADD_LSHIFT( x1[ n ] + x1[ n + 2 ], x1[ n + 1 ], 1 ), 9 ); /* Q11 */
sum = SKP_SMLAWB( SKP_LSHIFT( ( opus_int32 )x2[ n + 1 ], 8 ), sum, pred0_Q13 ); /* Q8 */
sum = SKP_SMLAWB( sum, SKP_LSHIFT( ( opus_int32 )x1[ n + 1 ], 11 ), pred1_Q13 ); /* Q8 */
x2[ n + 1 ] = (opus_int16)SKP_SAT16( SKP_RSHIFT_ROUND( sum, 8 ) );
}
state->pred_prev_Q13[ 0 ] = pred_Q13[ 0 ];
state->pred_prev_Q13[ 1 ] = pred_Q13[ 1 ];
/* Convert to left/right signals */
for( n = 0; n < frame_length; n++ ) {
sum = x1[ n + 1 ] + (opus_int32)x2[ n + 1 ];
diff = x1[ n + 1 ] - (opus_int32)x2[ n + 1 ];
x1[ n + 1 ] = (opus_int16)SKP_SAT16( sum );
x2[ n + 1 ] = (opus_int16)SKP_SAT16( diff );
}
}
/* even order AR filter */
void SKP_Silk_LPC_synthesis_filter(
const SKP_int16 *in, /* I: excitation signal */
const SKP_int16 *A_Q12, /* I: AR coefficients [Order], between -8_Q0 and 8_Q0 */
const SKP_int32 Gain_Q26, /* I: gain */
SKP_int32 *S, /* I/O: state vector [Order] */
SKP_int16 *out, /* O: output signal */
const SKP_int32 len, /* I: signal length */
const SKP_int Order /* I: filter order, must be even */
)
{
SKP_int k, j, idx, Order_half = SKP_RSHIFT( Order, 1 );
SKP_int32 SA, SB, out32_Q10, out32;
/* Order must be even */
SKP_assert( 2 * Order_half == Order );
/* S[] values are in Q14 */
for( k = 0; k < len; k++ ) {
SA = S[ Order - 1 ];
out32_Q10 = 0;
for( j = 0; j < ( Order_half - 1 ); j++ ) {
idx = SKP_SMULBB( 2, j ) + 1;
SB = S[ Order - 1 - idx ];
S[ Order - 1 - idx ] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, A_Q12[ ( j << 1 ) ] );
out32_Q10 = SKP_SMLAWB( out32_Q10, SB, A_Q12[ ( j << 1 ) + 1 ] );
SA = S[ Order - 2 - idx ];
S[ Order - 2 - idx ] = SB;
}
/* unrolled loop: epilog */
SB = S[ 0 ];
S[ 0 ] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, A_Q12[ Order - 2 ] );
out32_Q10 = SKP_SMLAWB( out32_Q10, SB, A_Q12[ Order - 1 ] );
/* apply gain to excitation signal and add to prediction */
out32_Q10 = SKP_ADD_SAT32( out32_Q10, SKP_SMULWB( Gain_Q26, in[ k ] ) );
/* scale to Q0 */
out32 = SKP_RSHIFT_ROUND( out32_Q10, 10 );
/* saturate output */
out[ k ] = ( SKP_int16 )SKP_SAT16( out32 );
/* move result into delay line */
S[ Order - 1 ] = SKP_LSHIFT_SAT32( out32_Q10, 4 );
}
}
/* non-warped frequency scale. (So that it can be implemented with a minimum-phase monic filter.) */
SKP_INLINE SKP_int32 warped_gain( // gain in Q16
const SKP_int32 *coefs_Q24,
SKP_int lambda_Q16,
SKP_int order
) {
SKP_int i;
SKP_int32 gain_Q24;
lambda_Q16 = -lambda_Q16;
gain_Q24 = coefs_Q24[ order - 1 ];
for( i = order - 2; i >= 0; i-- ) {
gain_Q24 = SKP_SMLAWB( coefs_Q24[ i ], gain_Q24, lambda_Q16 );
}
gain_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), gain_Q24, -lambda_Q16 );
return SKP_INVERSE32_varQ( gain_Q24, 40 );
}
void SKP_Silk_resampler_private_ARMA4(
SKP_int32 S[], /* I/O: State vector [ 4 ] */
SKP_int16 out[], /* O: Output signal */
const SKP_int16 in[], /* I: Input signal */
const SKP_int16 Coef[], /* I: ARMA coefficients [ 7 ] */
SKP_int32 len /* I: Signal length */
)
{
SKP_int32 k;
SKP_int32 in_Q8, out1_Q8, out2_Q8, X;
for( k = 0; k < len; k++ ) {
in_Q8 = SKP_LSHIFT32( (SKP_int32)in[ k ], 8 );
/* Outputs of first and second biquad */
out1_Q8 = SKP_ADD_LSHIFT32( in_Q8, S[ 0 ], 2 );
out2_Q8 = SKP_ADD_LSHIFT32( out1_Q8, S[ 2 ], 2 );
/* Update states, which are stored in Q6. Coefficients are in Q14 here */
X = SKP_SMLAWB( S[ 1 ], in_Q8, Coef[ 0 ] );
S[ 0 ] = SKP_SMLAWB( X, out1_Q8, Coef[ 2 ] );
X = SKP_SMLAWB( S[ 3 ], out1_Q8, Coef[ 1 ] );
S[ 2 ] = SKP_SMLAWB( X, out2_Q8, Coef[ 4 ] );
S[ 1 ] = SKP_SMLAWB( SKP_RSHIFT32( in_Q8, 2 ), out1_Q8, Coef[ 3 ] );
S[ 3 ] = SKP_SMLAWB( SKP_RSHIFT32( out1_Q8, 2 ), out2_Q8, Coef[ 5 ] );
/* Apply gain and store to output. The coefficient is in Q16 */
out[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT32( SKP_SMLAWB( 128, out2_Q8, Coef[ 6 ] ), 8 ) );
}
}
/* Convert input to a log scale */
opus_int32 silk_lin2log( const opus_int32 inLin ) /* I: Input in linear scale */
{
opus_int32 lz, frac_Q7;
silk_CLZ_FRAC( inLin, &lz, &frac_Q7 );
/* Piece-wise parabolic approximation */
return SKP_LSHIFT( 31 - lz, 7 ) + SKP_SMLAWB( frac_Q7, SKP_MUL( frac_Q7, 128 - frac_Q7 ), 179 );
}
/* Compute weighted quantization errors for an LPC_order element input vector, over one codebook stage */
void SKP_Silk_NLSF_VQ_sum_error_FIX(int32_t * err_Q20, /* O Weighted quantization errors [N*K] */
const int *in_Q15, /* I Input vectors to be quantized [N*LPC_order] */
const int *w_Q6, /* I Weighting vectors [N*LPC_order] */
const int16_t * pCB_Q15, /* I Codebook vectors [K*LPC_order] */
const int N, /* I Number of input vectors */
const int K, /* I Number of codebook vectors */
const int LPC_order /* I Number of LPCs */
)
{
int i, n, m;
int32_t diff_Q15, sum_error, Wtmp_Q6;
int32_t Wcpy_Q6[MAX_LPC_ORDER / 2];
const int16_t *cb_vec_Q15;
assert(LPC_order <= 16);
assert((LPC_order & 1) == 0);
memzero(Wcpy_Q6, (MAX_LPC_ORDER / 2) * sizeof(int32_t));
/* Copy to local stack and pack two weights per int32 */
for (m = 0; m < SKP_RSHIFT(LPC_order, 1); m++) {
Wcpy_Q6[m] =
w_Q6[2 * m] | SKP_LSHIFT((int32_t) w_Q6[2 * m + 1], 16);
}
/* Loop over input vectors */
for (n = 0; n < N; n++) {
/* Loop over codebook */
cb_vec_Q15 = pCB_Q15;
for (i = 0; i < K; i++) {
sum_error = 0;
for (m = 0; m < LPC_order; m += 2) {
/* Get two weights packed in an int32 */
Wtmp_Q6 = Wcpy_Q6[SKP_RSHIFT(m, 1)];
/* Compute weighted squared quantization error for index m */
diff_Q15 = in_Q15[m] - *cb_vec_Q15++; // range: [ -32767 : 32767 ]
sum_error =
SKP_SMLAWB(sum_error,
SKP_SMULBB(diff_Q15, diff_Q15),
Wtmp_Q6);
/* Compute weighted squared quantization error for index m + 1 */
diff_Q15 = in_Q15[m + 1] - *cb_vec_Q15++; // range: [ -32767 : 32767 ]
sum_error =
SKP_SMLAWT(sum_error,
SKP_SMULBB(diff_Q15, diff_Q15),
Wtmp_Q6);
}
assert(sum_error >= 0);
err_Q20[i] = sum_error;
}
err_Q20 += K;
in_Q15 += LPC_order;
}
}
/* Convert input to a linear scale */
SKP_int32 silk_log2lin( const SKP_int32 inLog_Q7 ) /* I: Input on log scale */
{
SKP_int32 out, frac_Q7;
if( inLog_Q7 < 0 ) {
return 0;
}
out = SKP_LSHIFT( 1, SKP_RSHIFT( inLog_Q7, 7 ) );
frac_Q7 = inLog_Q7 & 0x7F;
if( inLog_Q7 < 2048 ) {
/* Piece-wise parabolic approximation */
out = SKP_ADD_RSHIFT( out, SKP_MUL( out, SKP_SMLAWB( frac_Q7, SKP_MUL( frac_Q7, 128 - frac_Q7 ), -174 ) ), 7 );
} else {
/* Piece-wise parabolic approximation */
out = SKP_MLA( out, SKP_RSHIFT( out, 7 ), SKP_SMLAWB( frac_Q7, SKP_MUL( frac_Q7, 128 - frac_Q7 ), -174 ) );
}
return out;
}
SKP_INLINE SKP_int16 *SKP_Silk_resampler_private_down_FIR_INTERPOL0(
SKP_int16 *out, SKP_int32 *buf2, const SKP_int16 *FIR_Coefs, SKP_int32 max_index_Q16, SKP_int32 index_increment_Q16){
SKP_int32 index_Q16, res_Q6;
SKP_int32 *buf_ptr;
for( index_Q16 = 0; index_Q16 < max_index_Q16; index_Q16 += index_increment_Q16 ) {
/* Integer part gives pointer to buffered input */
buf_ptr = buf2 + SKP_RSHIFT( index_Q16, 16 );
/* Inner product */
res_Q6 = SKP_SMULWB( SKP_ADD32( buf_ptr[ 0 ], buf_ptr[ 11 ] ), FIR_Coefs[ 0 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 1 ], buf_ptr[ 10 ] ), FIR_Coefs[ 1 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 2 ], buf_ptr[ 9 ] ), FIR_Coefs[ 2 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 3 ], buf_ptr[ 8 ] ), FIR_Coefs[ 3 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 4 ], buf_ptr[ 7 ] ), FIR_Coefs[ 4 ] );
res_Q6 = SKP_SMLAWB( res_Q6, SKP_ADD32( buf_ptr[ 5 ], buf_ptr[ 6 ] ), FIR_Coefs[ 5 ] );
/* Scale down, saturate and store in output array */
*out++ = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( res_Q6, 6 ) );
}
return out;
}
/* SKP_Silk_prefilter. Prefilter for finding Quantizer input signal */
SKP_INLINE void SKP_Silk_prefilt_FIX(
SKP_Silk_prefilter_state_FIX *P, /* I/O state */
SKP_int32 st_res_Q12[], /* I short term residual signal */
SKP_int16 xw[], /* O prefiltered signal */
SKP_int32 HarmShapeFIRPacked_Q12, /* I Harmonic shaping coeficients */
SKP_int Tilt_Q14, /* I Tilt shaping coeficient */
SKP_int32 LF_shp_Q14, /* I Low-frequancy shaping coeficients*/
SKP_int lag, /* I Lag for harmonic shaping */
SKP_int length /* I Length of signals */
)
{
SKP_int i, idx, LTP_shp_buf_idx;
SKP_int32 n_LTP_Q12, n_Tilt_Q10, n_LF_Q10;
SKP_int32 sLF_MA_shp_Q12, sLF_AR_shp_Q12;
SKP_int16 *LTP_shp_buf;
/* To speed up use temp variables instead of using the struct */
LTP_shp_buf = P->sLTP_shp;
LTP_shp_buf_idx = P->sLTP_shp_buf_idx;
sLF_AR_shp_Q12 = P->sLF_AR_shp_Q12;
sLF_MA_shp_Q12 = P->sLF_MA_shp_Q12;
for( i = 0; i < length; i++ ) {
if( lag > 0 ) {
/* unrolled loop */
SKP_assert( HARM_SHAPE_FIR_TAPS == 3 );
idx = lag + LTP_shp_buf_idx;
n_LTP_Q12 = SKP_SMULBB( LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
n_LTP_Q12 = SKP_SMLABT( n_LTP_Q12, LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 ) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
n_LTP_Q12 = SKP_SMLABB( n_LTP_Q12, LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 + 1) & LTP_MASK ], HarmShapeFIRPacked_Q12 );
} else {
n_LTP_Q12 = 0;
}
n_Tilt_Q10 = SKP_SMULWB( sLF_AR_shp_Q12, Tilt_Q14 );
n_LF_Q10 = SKP_SMLAWB( SKP_SMULWT( sLF_AR_shp_Q12, LF_shp_Q14 ), sLF_MA_shp_Q12, LF_shp_Q14 );
sLF_AR_shp_Q12 = SKP_SUB32( st_res_Q12[ i ], SKP_LSHIFT( n_Tilt_Q10, 2 ) );
sLF_MA_shp_Q12 = SKP_SUB32( sLF_AR_shp_Q12, SKP_LSHIFT( n_LF_Q10, 2 ) );
LTP_shp_buf_idx = ( LTP_shp_buf_idx - 1 ) & LTP_MASK;
LTP_shp_buf[ LTP_shp_buf_idx ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( sLF_MA_shp_Q12, 12 ) );
xw[i] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SUB32( sLF_MA_shp_Q12, n_LTP_Q12 ), 12 ) );
}
/* Copy temp variable back to state */
P->sLF_AR_shp_Q12 = sLF_AR_shp_Q12;
P->sLF_MA_shp_Q12 = sLF_MA_shp_Q12;
P->sLTP_shp_buf_idx = LTP_shp_buf_idx;
}
/* Second order ARMA filter, alternative implementation */
void SKP_Silk_biquad_alt(
const SKP_int16 *in, /* I: Input signal */
const SKP_int32 *B_Q28, /* I: MA coefficients [3] */
const SKP_int32 *A_Q28, /* I: AR coefficients [2] */
SKP_int32 *S, /* I/O: State vector [2] */
SKP_int16 *out, /* O: Output signal */
const SKP_int32 len /* I: Signal length (must be even) */
)
{
/* DIRECT FORM II TRANSPOSED (uses 2 element state vector) */
SKP_int k;
SKP_int32 inval, A0_U_Q28, A0_L_Q28, A1_U_Q28, A1_L_Q28, out32_Q14;
/* Negate A_Q28 values and split in two parts */
A0_L_Q28 = ( -A_Q28[ 0 ] ) & 0x00003FFF; /* lower part */
A0_U_Q28 = SKP_RSHIFT( -A_Q28[ 0 ], 14 ); /* upper part */
A1_L_Q28 = ( -A_Q28[ 1 ] ) & 0x00003FFF; /* lower part */
A1_U_Q28 = SKP_RSHIFT( -A_Q28[ 1 ], 14 ); /* upper part */
for( k = 0; k < len; k++ ) {
/* S[ 0 ], S[ 1 ]: Q12 */
inval = in[ k ];
out32_Q14 = SKP_LSHIFT( SKP_SMLAWB( S[ 0 ], B_Q28[ 0 ], inval ), 2 );
S[ 0 ] = S[1] + SKP_RSHIFT_ROUND( SKP_SMULWB( out32_Q14, A0_L_Q28 ), 14 );
S[ 0 ] = SKP_SMLAWB( S[ 0 ], out32_Q14, A0_U_Q28 );
S[ 0 ] = SKP_SMLAWB( S[ 0 ], B_Q28[ 1 ], inval);
S[ 1 ] = SKP_RSHIFT_ROUND( SKP_SMULWB( out32_Q14, A1_L_Q28 ), 14 );
S[ 1 ] = SKP_SMLAWB( S[ 1 ], out32_Q14, A1_U_Q28 );
S[ 1 ] = SKP_SMLAWB( S[ 1 ], B_Q28[ 2 ], inval );
/* Scale back to Q0 and saturate */
out[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT( out32_Q14 + (1<<14) - 1, 14 ) );
}
}
/* Processing of gains */
void silk_process_gains_FIX(
silk_encoder_state_FIX *psEnc, /* I/O Encoder state_FIX */
silk_encoder_control_FIX *psEncCtrl /* I/O Encoder control_FIX */
)
{
silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
opus_int k;
opus_int32 s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart, quant_offset_Q10;
/* Gain reduction when LTP coding gain is high */
if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
/*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
s_Q16 = -silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - SILK_FIX_CONST( 12.0, 7 ), 4 ) );
for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
}
}
/* Limit the quantized signal */
/* InvMaxSqrVal = pow( 2.0f, 0.33f * ( 21.0f - SNR_dB ) ) / subfr_length; */
InvMaxSqrVal_Q16 = SKP_DIV32_16( silk_log2lin(
SKP_SMULWB( SILK_FIX_CONST( 21 + 16 / 0.33, 7 ) - psEnc->sCmn.SNR_dB_Q7, SILK_FIX_CONST( 0.33, 16 ) ) ), psEnc->sCmn.subfr_length );
for( k = 0; k < psEnc->sCmn.nb_subfr; k++ ) {
/* Soft limit on ratio residual energy and squared gains */
ResNrg = psEncCtrl->ResNrg[ k ];
ResNrgPart = SKP_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
} else {
if( ResNrgPart >= SKP_RSHIFT( SKP_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
ResNrgPart = SKP_int32_MAX;
} else {
ResNrgPart = SKP_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
}
}
gain = psEncCtrl->Gains_Q16[ k ];
gain_squared = SKP_ADD_SAT32( ResNrgPart, SKP_SMMUL( gain, gain ) );
if( gain_squared < SKP_int16_MAX ) {
/* recalculate with higher precision */
gain_squared = SKP_SMLAWW( SKP_LSHIFT( ResNrgPart, 16 ), gain, gain );
SKP_assert( gain_squared > 0 );
gain = silk_SQRT_APPROX( gain_squared ); /* Q8 */
gain = SKP_min( gain, SKP_int32_MAX >> 8 );
psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 ); /* Q16 */
} else {
/* Step up function, converts reflection coefficients to prediction coefficients */
void SKP_Silk_k2a(
SKP_int32 *A_Q24, /* O: Prediction coefficients [order] Q24 */
const SKP_int16 *rc_Q15, /* I: Reflection coefficients [order] Q15 */
const SKP_int32 order /* I: Prediction order */
)
{
SKP_int k, n;
SKP_int32 Atmp[ SKP_Silk_MAX_ORDER_LPC ];
for( k = 0; k < order; k++ ) {
for( n = 0; n < k; n++ ) {
Atmp[ n ] = A_Q24[ n ];
}
for( n = 0; n < k; n++ ) {
A_Q24[ n ] = SKP_SMLAWB( A_Q24[ n ], SKP_LSHIFT( Atmp[ k - n - 1 ], 1 ), rc_Q15[ k ] );
}
A_Q24[ k ] = -SKP_LSHIFT( (SKP_int32)rc_Q15[ k ], 9 );
}
}
/* Second order AR filter with single delay elements */
void SKP_Silk_resampler_private_AR2(
SKP_int32 S[], /* I/O: State vector [ 2 ] */
SKP_int32 out_Q8[], /* O: Output signal */
const SKP_int16 in[], /* I: Input signal */
const SKP_int16 A_Q14[], /* I: AR coefficients, Q14 */
SKP_int32 len /* I: Signal length */
)
{
SKP_int32 k;
SKP_int32 out32;
for( k = 0; k < len; k++ ) {
out32 = SKP_ADD_LSHIFT32( S[ 0 ], (SKP_int32)in[ k ], 8 );
out_Q8[ k ] = out32;
out32 = SKP_LSHIFT( out32, 2 );
S[ 0 ] = SKP_SMLAWB( S[ 1 ], out32, A_Q14[ 0 ] );
S[ 1 ] = SKP_SMULWB( out32, A_Q14[ 1 ] );
}
}
/* Upsample by a factor 4, Note: very low quality, only use with output sampling rates above 96 kHz. */
void SKP_Silk_resampler_private_up4(
SKP_int32 *S, /* I/O: State vector [ 2 ] */
SKP_int16 *out, /* O: Output signal [ 4 * len ] */
const SKP_int16 *in, /* I: Input signal [ len ] */
SKP_int32 len /* I: Number of INPUT samples */
)
{
SKP_int32 k;
SKP_int32 in32, out32, Y, X;
SKP_int16 out16;
SKP_assert( SKP_Silk_resampler_up2_lq_0 > 0 );
SKP_assert( SKP_Silk_resampler_up2_lq_1 < 0 );
/* Internal variables and state are in Q10 format */
for( k = 0; k < len; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ k ], 10 );
/* All-pass section for even output sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMULWB( Y, SKP_Silk_resampler_up2_lq_0 );
out32 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Convert back to int16 and store to output */
out16 = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( out32, 10 ) );
out[ 4 * k ] = out16;
out[ 4 * k + 1 ] = out16;
/* All-pass section for odd output sample */
Y = SKP_SUB32( in32, S[ 1 ] );
X = SKP_SMLAWB( Y, Y, SKP_Silk_resampler_up2_lq_1 );
out32 = SKP_ADD32( S[ 1 ], X );
S[ 1 ] = SKP_ADD32( in32, X );
/* Convert back to int16 and store to output */
out16 = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( out32, 10 ) );
out[ 4 * k + 2 ] = out16;
out[ 4 * k + 3 ] = out16;
}
}
/* Downsample by a factor 2, mediocre quality */
void SKP_Silk_resampler_down2(
SKP_int32 *S, /* I/O: State vector [ 2 ] */
SKP_int16 *out, /* O: Output signal [ len ] */
const SKP_int16 *in, /* I: Input signal [ floor(len/2) ] */
SKP_int32 inLen /* I: Number of input samples */
)
{
SKP_int32 k, len2 = SKP_RSHIFT32( inLen, 1 );
SKP_int32 in32, out32, Y, X;
SKP_assert( SKP_Silk_resampler_down2_0 > 0 );
SKP_assert( SKP_Silk_resampler_down2_1 < 0 );
/* Internal variables and state are in Q10 format */
for( k = 0; k < len2; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k ], 10 );
/* All-pass section for even input sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMLAWB( Y, Y, SKP_Silk_resampler_down2_1 );
out32 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k + 1 ], 10 );
/* All-pass section for odd input sample, and add to output of previous section */
Y = SKP_SUB32( in32, S[ 1 ] );
X = SKP_SMULWB( Y, SKP_Silk_resampler_down2_0 );
out32 = SKP_ADD32( out32, S[ 1 ] );
out32 = SKP_ADD32( out32, X );
S[ 1 ] = SKP_ADD32( in32, X );
/* Add, convert back to int16 and store to output */
out[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( out32, 11 ) );
}
}
/* Predictive dequantizer for NLSF residuals */
void silk_NLSF_residual_dequant( /* O Returns RD value in Q30 */
opus_int16 x_Q10[], /* O Output [ order ] */
const opus_int8 indices[], /* I Quantization indices [ order ] */
const opus_uint8 pred_coef_Q8[], /* I Backward predictor coefs [ order ] */
const opus_int quant_step_size_Q16, /* I Quantization step size */
const opus_int16 order /* I Number of input values */
)
{
opus_int i, out_Q10, pred_Q10;
out_Q10 = 0;
for( i = order-1; i >= 0; i-- ) {
pred_Q10 = SKP_RSHIFT( SKP_SMULBB( out_Q10, (opus_int16)pred_coef_Q8[ i ] ), 8 );
out_Q10 = SKP_LSHIFT( indices[ i ], 10 );
if( out_Q10 > 0 ) {
out_Q10 = SKP_SUB16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
} else if( out_Q10 < 0 ) {
out_Q10 = SKP_ADD16( out_Q10, SILK_FIX_CONST( NLSF_QUANT_LEVEL_ADJ, 10 ) );
}
out_Q10 = SKP_SMLAWB( pred_Q10, out_Q10, quant_step_size_Q16 );
x_Q10[ i ] = out_Q10;
}
}
void SKP_Silk_warped_LPC_analysis_filter_FIX(
SKP_int32 state[], /* I/O State [order + 1] */
SKP_int16 res[], /* O Residual signal [length] */
const SKP_int16 coef_Q13[], /* I Coefficients [order] */
const SKP_int16 input[], /* I Input signal [length] */
const SKP_int16 lambda_Q16, /* I Warping factor */
const SKP_int length, /* I Length of input signal */
const SKP_int order /* I Filter order (even) */
)
{
SKP_int n, i;
SKP_int32 acc_Q11, tmp1, tmp2;
/* Order must be even */
SKP_assert( ( order & 1 ) == 0 );
for( n = 0; n < length; n++ ) {
/* Output of lowpass section */
tmp2 = SKP_SMLAWB( state[ 0 ], state[ 1 ], lambda_Q16 );
state[ 0 ] = SKP_LSHIFT( input[ n ], 14 );
/* Output of allpass section */
tmp1 = SKP_SMLAWB( state[ 1 ], state[ 2 ] - tmp2, lambda_Q16 );
state[ 1 ] = tmp2;
acc_Q11 = SKP_SMULWB( tmp2, coef_Q13[ 0 ] );
/* Loop over allpass sections */
for( i = 2; i < order; i += 2 ) {
/* Output of allpass section */
tmp2 = SKP_SMLAWB( state[ i ], state[ i + 1 ] - tmp1, lambda_Q16 );
state[ i ] = tmp1;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp1, coef_Q13[ i - 1 ] );
/* Output of allpass section */
tmp1 = SKP_SMLAWB( state[ i + 1 ], state[ i + 2 ] - tmp2, lambda_Q16 );
state[ i + 1 ] = tmp2;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp2, coef_Q13[ i ] );
}
state[ order ] = tmp1;
acc_Q11 = SKP_SMLAWB( acc_Q11, tmp1, coef_Q13[ order - 1 ] );
res[ n ] = ( SKP_int16 )SKP_SAT16( ( SKP_int32 )input[ n ] - SKP_RSHIFT_ROUND( acc_Q11, 11 ) );
}
}
/* Split signal into two decimated bands using first-order allpass filters */
void SKP_Silk_ana_filt_bank_1(
const SKP_int16 *in, /* I: Input signal [N] */
SKP_int32 *S, /* I/O: State vector [2] */
SKP_int16 *outL, /* O: Low band [N/2] */
SKP_int16 *outH, /* O: High band [N/2] */
SKP_int32 *scratch, /* I: Scratch memory [3*N/2] */ // todo: remove - no longer used
const SKP_int32 N /* I: Number of input samples */
)
{
SKP_int k, N2 = SKP_RSHIFT( N, 1 );
SKP_int32 in32, X, Y, out_1, out_2;
/* Internal variables and state are in Q10 format */
for( k = 0; k < N2; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k ], 10 );
/* All-pass section for even input sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMLAWB( Y, Y, A_fb1_21[ 0 ] );
out_1 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ 2 * k + 1 ], 10 );
/* All-pass section for odd input sample */
Y = SKP_SUB32( in32, S[ 1 ] );
X = SKP_SMULWB( Y, A_fb1_20[ 0 ] );
out_2 = SKP_ADD32( S[ 1 ], X );
S[ 1 ] = SKP_ADD32( in32, X );
/* Add/subtract, convert back to int16 and store to output */
outL[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( SKP_ADD32( out_2, out_1 ), 11 ) );
outH[ k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SUB32( out_2, out_1 ), 11 ) );
}
}
/* amplitude of monic warped coefficients by using bandwidth expansion on the true coefficients */
SKP_INLINE void limit_warped_coefs(
SKP_int32 *coefs_syn_Q24,
SKP_int32 *coefs_ana_Q24,
SKP_int lambda_Q16,
SKP_int32 limit_Q24,
SKP_int order
) {
SKP_int i, iter, ind = 0;
SKP_int32 tmp, maxabs_Q24, chirp_Q16, gain_syn_Q16, gain_ana_Q16;
SKP_int32 nom_Q16, den_Q24;
/* Convert to monic coefficients */
lambda_Q16 = -lambda_Q16;
for( i = order - 1; i > 0; i-- ) {
coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
}
lambda_Q16 = -lambda_Q16;
nom_Q16 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16, lambda_Q16 );
den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
for( i = 0; i < order; i++ ) {
coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
}
for( iter = 0; iter < 10; iter++ ) {
/* Find maximum absolute value */
maxabs_Q24 = -1;
for( i = 0; i < order; i++ ) {
tmp = SKP_max( SKP_abs_int32( coefs_syn_Q24[ i ] ), SKP_abs_int32( coefs_ana_Q24[ i ] ) );
if( tmp > maxabs_Q24 ) {
maxabs_Q24 = tmp;
ind = i;
}
}
if( maxabs_Q24 <= limit_Q24 ) {
/* Coefficients are within range - done */
return;
}
/* Convert back to true warped coefficients */
for( i = 1; i < order; i++ ) {
coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
}
gain_syn_Q16 = SKP_INVERSE32_varQ( gain_syn_Q16, 32 );
gain_ana_Q16 = SKP_INVERSE32_varQ( gain_ana_Q16, 32 );
for( i = 0; i < order; i++ ) {
coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
}
/* Apply bandwidth expansion */
chirp_Q16 = SKP_FIX_CONST( 0.99, 16 ) - SKP_DIV32_varQ(
SKP_SMULWB( maxabs_Q24 - limit_Q24, SKP_SMLABB( SKP_FIX_CONST( 0.8, 10 ), SKP_FIX_CONST( 0.1, 10 ), iter ) ),
SKP_MUL( maxabs_Q24, ind + 1 ), 22 );
SKP_Silk_bwexpander_32( coefs_syn_Q24, order, chirp_Q16 );
SKP_Silk_bwexpander_32( coefs_ana_Q24, order, chirp_Q16 );
/* Convert to monic warped coefficients */
lambda_Q16 = -lambda_Q16;
for( i = order - 1; i > 0; i-- ) {
coefs_syn_Q24[ i - 1 ] = SKP_SMLAWB( coefs_syn_Q24[ i - 1 ], coefs_syn_Q24[ i ], lambda_Q16 );
coefs_ana_Q24[ i - 1 ] = SKP_SMLAWB( coefs_ana_Q24[ i - 1 ], coefs_ana_Q24[ i ], lambda_Q16 );
}
lambda_Q16 = -lambda_Q16;
nom_Q16 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 16 ), -lambda_Q16, lambda_Q16 );
den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_syn_Q24[ 0 ], lambda_Q16 );
gain_syn_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
den_Q24 = SKP_SMLAWB( SKP_FIX_CONST( 1.0, 24 ), coefs_ana_Q24[ 0 ], lambda_Q16 );
gain_ana_Q16 = SKP_DIV32_varQ( nom_Q16, den_Q24, 24 );
for( i = 0; i < order; i++ ) {
coefs_syn_Q24[ i ] = SKP_SMULWW( gain_syn_Q16, coefs_syn_Q24[ i ] );
coefs_ana_Q24[ i ] = SKP_SMULWW( gain_ana_Q16, coefs_ana_Q24[ i ] );
}
}
SKP_assert( 0 );
}
SKP_int SKP_Silk_VAD_GetSA_Q8( /* O Return value, 0 if success */
SKP_Silk_encoder_state *psEncC, /* I/O Encoder state */
const SKP_int16 pIn[] /* I PCM input */
)
{
SKP_int SA_Q15, pSNR_dB_Q7, input_tilt;
SKP_int decimated_framelength, dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;
SKP_int32 sumSquared, smooth_coef_Q16;
SKP_int16 HPstateTmp;
SKP_int16 X[ VAD_N_BANDS ][ MAX_FRAME_LENGTH / 2 ];
SKP_int32 Xnrg[ VAD_N_BANDS ];
SKP_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ];
SKP_int32 speech_nrg, x_tmp;
SKP_int ret = 0;
SKP_Silk_VAD_state *psSilk_VAD = &psEncC->sVAD;
/* Safety checks */
SKP_assert( VAD_N_BANDS == 4 );
SKP_assert( MAX_FRAME_LENGTH >= psEncC->frame_length );
SKP_assert( psEncC->frame_length <= 512 );
SKP_assert( psEncC->frame_length == 8 * SKP_RSHIFT( psEncC->frame_length, 3 ) );
/***********************/
/* Filter and Decimate */
/***********************/
/* 0-8 kHz to 0-4 kHz and 4-8 kHz */
SKP_Silk_ana_filt_bank_1( pIn, &psSilk_VAD->AnaState[ 0 ], &X[ 0 ][ 0 ], &X[ 3 ][ 0 ], psEncC->frame_length );
/* 0-4 kHz to 0-2 kHz and 2-4 kHz */
SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState1[ 0 ], &X[ 0 ][ 0 ], &X[ 2 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 1 ) );
/* 0-2 kHz to 0-1 kHz and 1-2 kHz */
SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState2[ 0 ], &X[ 0 ][ 0 ], &X[ 1 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 2 ) );
/*********************************************/
/* HP filter on lowest band (differentiator) */
/*********************************************/
decimated_framelength = SKP_RSHIFT( psEncC->frame_length, 3 );
X[ 0 ][ decimated_framelength - 1 ] = SKP_RSHIFT( X[ 0 ][ decimated_framelength - 1 ], 1 );
HPstateTmp = X[ 0 ][ decimated_framelength - 1 ];
for( i = decimated_framelength - 1; i > 0; i-- ) {
X[ 0 ][ i - 1 ] = SKP_RSHIFT( X[ 0 ][ i - 1 ], 1 );
X[ 0 ][ i ] -= X[ 0 ][ i - 1 ];
}
X[ 0 ][ 0 ] -= psSilk_VAD->HPstate;
psSilk_VAD->HPstate = HPstateTmp;
/*************************************/
/* Calculate the energy in each band */
/*************************************/
for( b = 0; b < VAD_N_BANDS; b++ ) {
/* Find the decimated framelength in the non-uniformly divided bands */
decimated_framelength = SKP_RSHIFT( psEncC->frame_length, SKP_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) );
/* Split length into subframe lengths */
dec_subframe_length = SKP_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 );
dec_subframe_offset = 0;
/* Compute energy per sub-frame */
/* initialize with summed energy of last subframe */
Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ];
for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) {
sumSquared = 0;
for( i = 0; i < dec_subframe_length; i++ ) {
/* The energy will be less than dec_subframe_length * ( SKP_int16_MIN / 8 ) ^ 2. */
/* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128) */
x_tmp = SKP_RSHIFT( X[ b ][ i + dec_subframe_offset ], 3 );
sumSquared = SKP_SMLABB( sumSquared, x_tmp, x_tmp );
/* Safety check */
SKP_assert( sumSquared >= 0 );
}
/* Add/saturate summed energy of current subframe */
if( s < VAD_INTERNAL_SUBFRAMES - 1 ) {
Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], sumSquared );
} else {
/* Look-ahead subframe */
Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], SKP_RSHIFT( sumSquared, 1 ) );
}
dec_subframe_offset += dec_subframe_length;
}
psSilk_VAD->XnrgSubfr[ b ] = sumSquared;
}
/********************/
/* Noise estimation */
/********************/
SKP_Silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD );
/***********************************************/
/* Signal-plus-noise to noise ratio estimation */
/***********************************************/
sumSquared = 0;
input_tilt = 0;
for( b = 0; b < VAD_N_BANDS; b++ ) {
speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ];
if( speech_nrg > 0 ) {
/* Divide, with sufficient resolution */
if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) {
NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( SKP_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 );
} else {
NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( Xnrg[ b ], SKP_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 );
}
/* Convert to log domain */
SNR_Q7 = SKP_Silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128;
/* Sum-of-squares */
sumSquared = SKP_SMLABB( sumSquared, SNR_Q7, SNR_Q7 ); /* Q14 */
/* Tilt measure */
if( speech_nrg < ( 1 << 20 ) ) {
/* Scale down SNR value for small subband speech energies */
SNR_Q7 = SKP_SMULWB( SKP_LSHIFT( SKP_Silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 );
}
input_tilt = SKP_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 );
} else {
NrgToNoiseRatio_Q8[ b ] = 256;
}
}
/* Mean-of-squares */
sumSquared = SKP_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */
/* Root-mean-square approximation, scale to dBs, and write to output pointer */
pSNR_dB_Q7 = ( SKP_int16 )( 3 * SKP_Silk_SQRT_APPROX( sumSquared ) ); /* Q7 */
/*********************************/
/* Speech Probability Estimation */
/*********************************/
SA_Q15 = SKP_Silk_sigm_Q15( SKP_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 );
/**************************/
/* Frequency Tilt Measure */
/**************************/
psEncC->input_tilt_Q15 = SKP_LSHIFT( SKP_Silk_sigm_Q15( input_tilt ) - 16384, 1 );
/**************************************************/
/* Scale the sigmoid output based on power levels */
/**************************************************/
speech_nrg = 0;
for( b = 0; b < VAD_N_BANDS; b++ ) {
/* Accumulate signal-without-noise energies, higher frequency bands have more weight */
speech_nrg += ( b + 1 ) * SKP_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );
}
/* Power scaling */
if( speech_nrg <= 0 ) {
SA_Q15 = SKP_RSHIFT( SA_Q15, 1 );
} else if( speech_nrg < 32768 ) {
if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 16 );
} else {
speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 15 );
}
/* square-root */
speech_nrg = SKP_Silk_SQRT_APPROX( speech_nrg );
SA_Q15 = SKP_SMULWB( 32768 + speech_nrg, SA_Q15 );
}
/* Copy the resulting speech activity in Q8 */
psEncC->speech_activity_Q8 = SKP_min_int( SKP_RSHIFT( SA_Q15, 7 ), SKP_uint8_MAX );
/***********************************/
/* Energy Level and SNR estimation */
/***********************************/
/* Smoothing coefficient */
smooth_coef_Q16 = SKP_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, SKP_SMULWB( SA_Q15, SA_Q15 ) );
if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
smooth_coef_Q16 >>= 1;
}
/* High-pass filter with cutoff frequency adaptation based on pitch lag statistics */
void SKP_Silk_HP_variable_cutoff_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */
SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */
SKP_int16 *out, /* O high-pass filtered output signal */
const SKP_int16 *in /* I input signal */
)
{
SKP_int quality_Q15;
SKP_int32 B_Q28[ 3 ], A_Q28[ 2 ];
SKP_int32 Fc_Q19, r_Q28, r_Q22;
SKP_int32 pitch_freq_Hz_Q16, pitch_freq_log_Q7, delta_freq_Q7;
/*********************************************/
/* Estimate Low End of Pitch Frequency Range */
/*********************************************/
if( psEnc->sCmn.prev_sigtype == SIG_TYPE_VOICED ) {
/* difference, in log domain */
pitch_freq_Hz_Q16 = SKP_DIV32_16( SKP_LSHIFT( SKP_MUL( psEnc->sCmn.fs_kHz, 1000 ), 16 ), psEnc->sCmn.prevLag );
pitch_freq_log_Q7 = SKP_Silk_lin2log( pitch_freq_Hz_Q16 ) - ( 16 << 7 ); //0x70
/* adjustment based on quality */
quality_Q15 = psEncCtrl->input_quality_bands_Q15[ 0 ];
pitch_freq_log_Q7 = SKP_SUB32( pitch_freq_log_Q7, SKP_SMULWB( SKP_SMULWB( SKP_LSHIFT( quality_Q15, 2 ), quality_Q15 ),
pitch_freq_log_Q7 - SKP_LOG2_VARIABLE_HP_MIN_FREQ_Q7 ) );
pitch_freq_log_Q7 = SKP_ADD32( pitch_freq_log_Q7, SKP_RSHIFT( SKP_FIX_CONST( 0.6, 15 ) - quality_Q15, 9 ) );
//delta_freq = pitch_freq_log - psEnc->variable_HP_smth1;
delta_freq_Q7 = pitch_freq_log_Q7 - SKP_RSHIFT( psEnc->variable_HP_smth1_Q15, 8 );
if( delta_freq_Q7 < 0 ) {
/* less smoothing for decreasing pitch frequency, to track something close to the minimum */
delta_freq_Q7 = SKP_MUL( delta_freq_Q7, 3 );
}
/* limit delta, to reduce impact of outliers */
delta_freq_Q7 = SKP_LIMIT_32( delta_freq_Q7, -SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ), SKP_FIX_CONST( VARIABLE_HP_MAX_DELTA_FREQ, 7 ) );
/* update smoother */
psEnc->variable_HP_smth1_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth1_Q15,
SKP_MUL( SKP_LSHIFT( psEnc->speech_activity_Q8, 1 ), delta_freq_Q7 ), SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF1, 16 ) );
}
/* second smoother */
psEnc->variable_HP_smth2_Q15 = SKP_SMLAWB( psEnc->variable_HP_smth2_Q15,
psEnc->variable_HP_smth1_Q15 - psEnc->variable_HP_smth2_Q15, SKP_FIX_CONST( VARIABLE_HP_SMTH_COEF2, 16 ) );
/* convert from log scale to Hertz */
psEncCtrl->pitch_freq_low_Hz = SKP_Silk_log2lin( SKP_RSHIFT( psEnc->variable_HP_smth2_Q15, 8 ) );
/* limit frequency range */
psEncCtrl->pitch_freq_low_Hz = SKP_LIMIT_32( psEncCtrl->pitch_freq_low_Hz,
SKP_FIX_CONST( VARIABLE_HP_MIN_FREQ, 0 ), SKP_FIX_CONST( VARIABLE_HP_MAX_FREQ, 0 ) );
/********************************/
/* Compute Filter Coefficients */
/********************************/
/* compute cut-off frequency, in radians */
//Fc_num = (SKP_float)( 0.45f * 2.0f * 3.14159265359 * psEncCtrl->pitch_freq_low_Hz );
//Fc_denom = (SKP_float)( 1e3f * psEnc->sCmn.fs_kHz );
SKP_assert( psEncCtrl->pitch_freq_low_Hz <= SKP_int32_MAX / SKP_RADIANS_CONSTANT_Q19 );
Fc_Q19 = SKP_DIV32_16( SKP_SMULBB( SKP_RADIANS_CONSTANT_Q19, psEncCtrl->pitch_freq_low_Hz ), psEnc->sCmn.fs_kHz ); // range: 3704 - 27787, 11-15 bits
SKP_assert( Fc_Q19 >= 3704 );
SKP_assert( Fc_Q19 <= 27787 );
r_Q28 = SKP_FIX_CONST( 1.0, 28 ) - SKP_MUL( SKP_FIX_CONST( 0.92, 9 ), Fc_Q19 );
SKP_assert( r_Q28 >= 255347779 );
SKP_assert( r_Q28 <= 266690872 );
/* b = r * [ 1; -2; 1 ]; */
/* a = [ 1; -2 * r * ( 1 - 0.5 * Fc^2 ); r^2 ]; */
B_Q28[ 0 ] = r_Q28;
B_Q28[ 1 ] = SKP_LSHIFT( -r_Q28, 1 );
B_Q28[ 2 ] = r_Q28;
// -r * ( 2 - Fc * Fc );
r_Q22 = SKP_RSHIFT( r_Q28, 6 );
A_Q28[ 0 ] = SKP_SMULWW( r_Q22, SKP_SMULWW( Fc_Q19, Fc_Q19 ) - SKP_FIX_CONST( 2.0, 22 ) );
A_Q28[ 1 ] = SKP_SMULWW( r_Q22, r_Q22 );
/********************************/
/* High-Pass Filter */
/********************************/
SKP_Silk_biquad_alt( in, B_Q28, A_Q28, psEnc->sCmn.In_HP_State, out, psEnc->sCmn.frame_length );
}
void SKP_Silk_noise_shape_analysis_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state FIX */
SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control FIX */
const SKP_int16 *pitch_res, /* I LPC residual from pitch analysis */
const SKP_int16 *x /* I Input signal [ frame_length + la_shape ] */
)
{
SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
SKP_int k, i, nSamples, Qnrg, b_Q14, warping_Q16, scale = 0;
SKP_int32 SNR_adj_dB_Q7, HarmBoost_Q16, HarmShapeGain_Q16, Tilt_Q16, tmp32;
SKP_int32 nrg, pre_nrg_Q30, log_energy_Q7, log_energy_prev_Q7, energy_variation_Q7;
SKP_int32 delta_Q16, BWExp1_Q16, BWExp2_Q16, gain_mult_Q16, gain_add_Q16, strength_Q16, b_Q8;
SKP_int32 auto_corr[ MAX_SHAPE_LPC_ORDER + 1 ];
SKP_int32 refl_coef_Q16[ MAX_SHAPE_LPC_ORDER ];
SKP_int32 AR1_Q24[ MAX_SHAPE_LPC_ORDER ];
SKP_int32 AR2_Q24[ MAX_SHAPE_LPC_ORDER ];
SKP_int16 x_windowed[ SHAPE_LPC_WIN_MAX ];
const SKP_int16 *x_ptr, *pitch_res_ptr;
SKP_int32 sqrt_nrg[ NB_SUBFR ], Qnrg_vec[ NB_SUBFR ];
/* Point to start of first LPC analysis block */
x_ptr = x - psEnc->sCmn.la_shape;
/****************/
/* CONTROL SNR */
/****************/
/* Reduce SNR_dB values if recent bitstream has exceeded TargetRate */
psEncCtrl->current_SNR_dB_Q7 = psEnc->SNR_dB_Q7 - SKP_SMULWB( SKP_LSHIFT( ( SKP_int32 )psEnc->BufferedInChannel_ms, 7 ),
SKP_FIX_CONST( 0.05, 16 ) );
/* Reduce SNR_dB if inband FEC used */
if( psEnc->speech_activity_Q8 > SKP_FIX_CONST( LBRR_SPEECH_ACTIVITY_THRES, 8 ) ) {
psEncCtrl->current_SNR_dB_Q7 -= SKP_RSHIFT( psEnc->inBandFEC_SNR_comp_Q8, 1 );
}
/****************/
/* GAIN CONTROL */
/****************/
/* Input quality is the average of the quality in the lowest two VAD bands */
psEncCtrl->input_quality_Q14 = ( SKP_int )SKP_RSHIFT( ( SKP_int32 )psEncCtrl->input_quality_bands_Q15[ 0 ]
+ psEncCtrl->input_quality_bands_Q15[ 1 ], 2 );
/* Coding quality level, between 0.0_Q0 and 1.0_Q0, but in Q14 */
psEncCtrl->coding_quality_Q14 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->current_SNR_dB_Q7 -
SKP_FIX_CONST( 18.0, 7 ), 4 ) ), 1 );
/* Reduce coding SNR during low speech activity */
b_Q8 = SKP_FIX_CONST( 1.0, 8 ) - psEnc->speech_activity_Q8;
b_Q8 = SKP_SMULWB( SKP_LSHIFT( b_Q8, 8 ), b_Q8 );
SNR_adj_dB_Q7 = SKP_SMLAWB( psEncCtrl->current_SNR_dB_Q7,
SKP_SMULBB( SKP_FIX_CONST( -BG_SNR_DECR_dB, 7 ) >> ( 4 + 1 ), b_Q8 ), // Q11
SKP_SMULWB( SKP_FIX_CONST( 1.0, 14 ) + psEncCtrl->input_quality_Q14, psEncCtrl->coding_quality_Q14 ) ); // Q12
if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
/* Reduce gains for periodic signals */
SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( HARM_SNR_INCR_dB, 8 ), psEnc->LTPCorr_Q15 );
} else {
/* For unvoiced signals and low-quality input, adjust the quality slower than SNR_dB setting */
SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7,
SKP_SMLAWB( SKP_FIX_CONST( 6.0, 9 ), -SKP_FIX_CONST( 0.4, 18 ), psEncCtrl->current_SNR_dB_Q7 ),
SKP_FIX_CONST( 1.0, 14 ) - psEncCtrl->input_quality_Q14 );
}
/*************************/
/* SPARSENESS PROCESSING */
/*************************/
/* Set quantizer offset */
if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
/* Initally set to 0; may be overruled in process_gains(..) */
psEncCtrl->sCmn.QuantOffsetType = 0;
psEncCtrl->sparseness_Q8 = 0;
} else {
/* Sparseness measure, based on relative fluctuations of energy per 2 milliseconds */
nSamples = SKP_LSHIFT( psEnc->sCmn.fs_kHz, 1 );
energy_variation_Q7 = 0;
log_energy_prev_Q7 = 0;
pitch_res_ptr = pitch_res;
for( k = 0; k < FRAME_LENGTH_MS / 2; k++ ) {
SKP_Silk_sum_sqr_shift( &nrg, &scale, pitch_res_ptr, nSamples );
nrg += SKP_RSHIFT( nSamples, scale ); // Q(-scale)
log_energy_Q7 = SKP_Silk_lin2log( nrg );
if( k > 0 ) {
energy_variation_Q7 += SKP_abs( log_energy_Q7 - log_energy_prev_Q7 );
}
log_energy_prev_Q7 = log_energy_Q7;
pitch_res_ptr += nSamples;
}
psEncCtrl->sparseness_Q8 = SKP_RSHIFT( SKP_Silk_sigm_Q15( SKP_SMULWB( energy_variation_Q7 -
SKP_FIX_CONST( 5.0, 7 ), SKP_FIX_CONST( 0.1, 16 ) ) ), 7 );
/* Set quantization offset depending on sparseness measure */
if( psEncCtrl->sparseness_Q8 > SKP_FIX_CONST( SPARSENESS_THRESHOLD_QNT_OFFSET, 8 ) ) {
psEncCtrl->sCmn.QuantOffsetType = 0;
} else {
psEncCtrl->sCmn.QuantOffsetType = 1;
}
/* Increase coding SNR for sparse signals */
SNR_adj_dB_Q7 = SKP_SMLAWB( SNR_adj_dB_Q7, SKP_FIX_CONST( SPARSE_SNR_INCR_dB, 15 ), psEncCtrl->sparseness_Q8 - SKP_FIX_CONST( 0.5, 8 ) );
}
/*******************************/
/* Control bandwidth expansion */
/*******************************/
/* More BWE for signals with high prediction gain */
strength_Q16 = SKP_SMULWB( psEncCtrl->predGain_Q16, SKP_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) );
BWExp1_Q16 = BWExp2_Q16 = SKP_DIV32_varQ( SKP_FIX_CONST( BANDWIDTH_EXPANSION, 16 ),
SKP_SMLAWW( SKP_FIX_CONST( 1.0, 16 ), strength_Q16, strength_Q16 ), 16 );
delta_Q16 = SKP_SMULWB( SKP_FIX_CONST( 1.0, 16 ) - SKP_SMULBB( 3, psEncCtrl->coding_quality_Q14 ),
SKP_FIX_CONST( LOW_RATE_BANDWIDTH_EXPANSION_DELTA, 16 ) );
BWExp1_Q16 = SKP_SUB32( BWExp1_Q16, delta_Q16 );
BWExp2_Q16 = SKP_ADD32( BWExp2_Q16, delta_Q16 );
/* BWExp1 will be applied after BWExp2, so make it relative */
BWExp1_Q16 = SKP_DIV32_16( SKP_LSHIFT( BWExp1_Q16, 14 ), SKP_RSHIFT( BWExp2_Q16, 2 ) );
if( psEnc->sCmn.warping_Q16 > 0 ) {
/* Slightly more warping in analysis will move quantization noise up in frequency, where it's better masked */
warping_Q16 = SKP_SMLAWB( psEnc->sCmn.warping_Q16, psEncCtrl->coding_quality_Q14, SKP_FIX_CONST( 0.01, 18 ) );
} else {
warping_Q16 = 0;
}
/********************************************/
/* Compute noise shaping AR coefs and gains */
/********************************************/
for( k = 0; k < NB_SUBFR; k++ ) {
/* Apply window: sine slope followed by flat part followed by cosine slope */
SKP_int shift, slope_part, flat_part;
flat_part = psEnc->sCmn.fs_kHz * 5;
slope_part = SKP_RSHIFT( psEnc->sCmn.shapeWinLength - flat_part, 1 );
SKP_Silk_apply_sine_window_new( x_windowed, x_ptr, 1, slope_part );
shift = slope_part;
SKP_memcpy( x_windowed + shift, x_ptr + shift, flat_part * sizeof(SKP_int16) );
shift += flat_part;
SKP_Silk_apply_sine_window_new( x_windowed + shift, x_ptr + shift, 2, slope_part );
/* Update pointer: next LPC analysis block */
x_ptr += psEnc->sCmn.subfr_length;
if( psEnc->sCmn.warping_Q16 > 0 ) {
/* Calculate warped auto correlation */
SKP_Silk_warped_autocorrelation_FIX( auto_corr, &scale, x_windowed, warping_Q16, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder );
} else {
/* Calculate regular auto correlation */
SKP_Silk_autocorr( auto_corr, &scale, x_windowed, psEnc->sCmn.shapeWinLength, psEnc->sCmn.shapingLPCOrder + 1 );
}
/* Add white noise, as a fraction of energy */
auto_corr[0] = SKP_ADD32( auto_corr[0], SKP_max_32( SKP_SMULWB( SKP_RSHIFT( auto_corr[ 0 ], 4 ),
SKP_FIX_CONST( SHAPE_WHITE_NOISE_FRACTION, 20 ) ), 1 ) );
/* Calculate the reflection coefficients using schur */
nrg = SKP_Silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder );
SKP_assert( nrg >= 0 );
/* Convert reflection coefficients to prediction coefficients */
SKP_Silk_k2a_Q16( AR2_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder );
Qnrg = -scale; // range: -12...30
SKP_assert( Qnrg >= -12 );
SKP_assert( Qnrg <= 30 );
/* Make sure that Qnrg is an even number */
if( Qnrg & 1 ) {
Qnrg -= 1;
nrg >>= 1;
}
tmp32 = SKP_Silk_SQRT_APPROX( nrg );
Qnrg >>= 1; // range: -6...15
sqrt_nrg[ k ] = tmp32;
Qnrg_vec[ k ] = Qnrg;
psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( tmp32, 16 - Qnrg );
if( psEnc->sCmn.warping_Q16 > 0 ) {
/* Adjust gain for warping */
gain_mult_Q16 = warped_gain( AR2_Q24, warping_Q16, psEnc->sCmn.shapingLPCOrder );
SKP_assert( psEncCtrl->Gains_Q16[ k ] >= 0 );
psEncCtrl->Gains_Q16[ k ] = SKP_SMULWW( psEncCtrl->Gains_Q16[ k ], gain_mult_Q16 );
if( psEncCtrl->Gains_Q16[ k ] < 0 ) {
psEncCtrl->Gains_Q16[ k ] = SKP_int32_MAX;
}
}
/* Bandwidth expansion for synthesis filter shaping */
SKP_Silk_bwexpander_32( AR2_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 );
/* Compute noise shaping filter coefficients */
SKP_memcpy( AR1_Q24, AR2_Q24, psEnc->sCmn.shapingLPCOrder * sizeof( SKP_int32 ) );
/* Bandwidth expansion for analysis filter shaping */
SKP_assert( BWExp1_Q16 <= SKP_FIX_CONST( 1.0, 16 ) );
SKP_Silk_bwexpander_32( AR1_Q24, psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 );
/* Ratio of prediction gains, in energy domain */
SKP_Silk_LPC_inverse_pred_gain_Q24( &pre_nrg_Q30, AR2_Q24, psEnc->sCmn.shapingLPCOrder );
SKP_Silk_LPC_inverse_pred_gain_Q24( &nrg, AR1_Q24, psEnc->sCmn.shapingLPCOrder );
//psEncCtrl->GainsPre[ k ] = 1.0f - 0.7f * ( 1.0f - pre_nrg / nrg ) = 0.3f + 0.7f * pre_nrg / nrg;
pre_nrg_Q30 = SKP_LSHIFT32( SKP_SMULWB( pre_nrg_Q30, SKP_FIX_CONST( 0.7, 15 ) ), 1 );
psEncCtrl->GainsPre_Q14[ k ] = ( SKP_int ) SKP_FIX_CONST( 0.3, 14 ) + SKP_DIV32_varQ( pre_nrg_Q30, nrg, 14 );
/* Convert to monic warped prediction coefficients and limit absolute values */
limit_warped_coefs( AR2_Q24, AR1_Q24, warping_Q16, SKP_FIX_CONST( 3.999, 24 ), psEnc->sCmn.shapingLPCOrder );
/* Convert from Q24 to Q13 and store in int16 */
for( i = 0; i < psEnc->sCmn.shapingLPCOrder; i++ ) {
psEncCtrl->AR1_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR1_Q24[ i ], 11 ) );
psEncCtrl->AR2_Q13[ k * MAX_SHAPE_LPC_ORDER + i ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT_ROUND( AR2_Q24[ i ], 11 ) );
}
}
/* even order AR filter */
void SKP_Silk_LPC_synthesis_filter(
const SKP_int16 *in, /* I: excitation signal */
const SKP_int16 *A_Q12, /* I: AR coefficients [Order], between -8_Q0 and 8_Q0 */
const SKP_int32 Gain_Q26, /* I: gain */
SKP_int32 *S, /* I/O: state vector [Order] */
SKP_int16 *out, /* O: output signal */
const SKP_int32 len, /* I: signal length */
const SKP_int Order /* I: filter order, must be even */
)
{
SKP_int k, j, idx, Order_half = SKP_RSHIFT( Order, 1 );
SKP_int32 SA, SB, Atmp, A_align_Q12[SigProc_MAX_ORDER_LPC >> 1], out32_Q10, out32;
/* Order must be even */
SKP_assert( 2*Order_half == Order );
/* combine two A_Q12 values and ensure 32-bit alignment */
for( k = 0; k < Order_half; k++ ) {
idx = SKP_SMULBB( 2, k );
A_align_Q12[k] = (((SKP_int32)A_Q12[idx]) & 0x0000ffff) | SKP_LSHIFT( (SKP_int32)A_Q12[idx+1], 16 );
}
/* S[] values are in Q14 */
for( k = 0; k < len; k++ ) {
SA = S[Order-1];
out32_Q10 = 0;
for( j=0;j<(Order_half-1); j++ ) {
idx = SKP_SMULBB( 2, j ) + 1;
/* multiply-add two prediction coefficients for each loop */
/* NOTE: the code below loads two int16 values in an int32, and multiplies each using the */
/* SMLAWB and SMLAWT instructions. On a big-endian CPU the two int16 variables would be */
/* loaded in reverse order and the code will give the wrong result. In that case swapping */
/* the SMLAWB and SMLAWT instructions should solve the problem. */
Atmp = A_align_Q12[j];
SB = S[Order - 1 - idx];
S[Order - 1 - idx] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, Atmp );
out32_Q10 = SKP_SMLAWT( out32_Q10, SB, Atmp );
SA = S[Order - 2 - idx];
S[Order - 2 - idx] = SB;
}
/* unrolled loop: epilog */
Atmp = A_align_Q12[Order_half-1];
SB = S[0];
S[0] = SA;
out32_Q10 = SKP_SMLAWB( out32_Q10, SA, Atmp );
out32_Q10 = SKP_SMLAWT( out32_Q10, SB, Atmp );
/* apply gain to excitation signal and add to prediction */
out32_Q10 = SKP_ADD_SAT32( out32_Q10, SKP_SMULWB( Gain_Q26, in[k] ) );
/* scale to Q0 */
out32 = SKP_RSHIFT_ROUND( out32_Q10, 10 );
/* saturate output */
out[k] = (SKP_int16)SKP_SAT16( out32 );
/* move result into delay line */
S[Order - 1] = SKP_LSHIFT_SAT32( out32_Q10, 4 );
}
}
void SKP_Silk_PLC_conceal(
SKP_Silk_decoder_state *psDec, /* I/O Decoder state */
SKP_Silk_decoder_control *psDecCtrl, /* I/O Decoder control */
SKP_int16 signal[], /* O concealed signal */
SKP_int length /* I length of residual */
)
{
SKP_int i, j, k;
SKP_int16 *B_Q14, exc_buf[ MAX_FRAME_LENGTH ], *exc_buf_ptr;
SKP_int16 rand_scale_Q14, A_Q12_tmp[ MAX_LPC_ORDER ];
SKP_int32 rand_seed, harm_Gain_Q15, rand_Gain_Q15;
SKP_int lag, idx, shift1, shift2;
SKP_int32 energy1, energy2, *rand_ptr, *pred_lag_ptr, Atmp;
SKP_int32 sig_Q10[ MAX_FRAME_LENGTH ], *sig_Q10_ptr, LPC_exc_Q10, LPC_pred_Q10, LTP_pred_Q14;
SKP_Silk_PLC_struct *psPLC;
psPLC = &psDec->sPLC;
/* Update LTP buffer */
SKP_memcpy( psDec->sLTP_Q16, &psDec->sLTP_Q16[ psDec->frame_length ], psDec->frame_length * sizeof( SKP_int32 ) );
/* LPC concealment. Apply BWE to previous LPC */
SKP_Silk_bwexpander( psPLC->prevLPC_Q12, psDec->LPC_order, BWE_COEF_Q16 );
/* Find random noise component */
/* Scale previous excitation signal */
exc_buf_ptr = exc_buf;
for( k = ( NB_SUBFR >> 1 ); k < NB_SUBFR; k++ ) {
for( i = 0; i < psDec->subfr_length; i++ ) {
exc_buf_ptr[ i ] = ( SKP_int16 )SKP_RSHIFT(
SKP_SMULWW( psDec->exc_Q10[ i + k * psDec->subfr_length ], psPLC->prevGain_Q16[ k ] ), 10 );
}
exc_buf_ptr += psDec->subfr_length;
}
/* Find the subframe with lowest energy of the last two and use that as random noise generator */
SKP_Silk_sum_sqr_shift( &energy1, &shift1, exc_buf, psDec->subfr_length );
SKP_Silk_sum_sqr_shift( &energy2, &shift2, &exc_buf[ psDec->subfr_length ], psDec->subfr_length );
if( SKP_RSHIFT( energy1, shift2 ) < SKP_RSHIFT( energy1, shift2 ) ) {
/* First sub-frame has lowest energy */
rand_ptr = &psDec->exc_Q10[ SKP_max_int( 0, 3 * psDec->subfr_length - RAND_BUF_SIZE ) ];
} else {
/* Second sub-frame has lowest energy */
rand_ptr = &psDec->exc_Q10[ SKP_max_int( 0, psDec->frame_length - RAND_BUF_SIZE ) ];
}
/* Setup Gain to random noise component */
B_Q14 = psPLC->LTPCoef_Q14;
rand_scale_Q14 = psPLC->randScale_Q14;
/* Setup attenuation gains */
harm_Gain_Q15 = HARM_ATT_Q15[ SKP_min_int( NB_ATT - 1, psDec->lossCnt ) ];
if( psDec->prev_sigtype == SIG_TYPE_VOICED ) {
rand_Gain_Q15 = PLC_RAND_ATTENUATE_V_Q15[ SKP_min_int( NB_ATT - 1, psDec->lossCnt ) ];
} else {
rand_Gain_Q15 = PLC_RAND_ATTENUATE_UV_Q15[ SKP_min_int( NB_ATT - 1, psDec->lossCnt ) ];
}
/* First Lost frame */
if( psDec->lossCnt == 0 ) {
rand_scale_Q14 = (1 << 14 );
/* Reduce random noise Gain for voiced frames */
if( psDec->prev_sigtype == SIG_TYPE_VOICED ) {
for( i = 0; i < LTP_ORDER; i++ ) {
rand_scale_Q14 -= B_Q14[ i ];
}
rand_scale_Q14 = SKP_max_16( 3277, rand_scale_Q14 ); /* 0.2 */
rand_scale_Q14 = ( SKP_int16 )SKP_RSHIFT( SKP_SMULBB( rand_scale_Q14, psPLC->prevLTP_scale_Q14 ), 14 );
}
/* Reduce random noise for unvoiced frames with high LPC gain */
if( psDec->prev_sigtype == SIG_TYPE_UNVOICED ) {
SKP_int32 invGain_Q30, down_scale_Q30;
SKP_Silk_LPC_inverse_pred_gain( &invGain_Q30, psPLC->prevLPC_Q12, psDec->LPC_order );
down_scale_Q30 = SKP_min_32( SKP_RSHIFT( ( 1 << 30 ), LOG2_INV_LPC_GAIN_HIGH_THRES ), invGain_Q30 );
down_scale_Q30 = SKP_max_32( SKP_RSHIFT( ( 1 << 30 ), LOG2_INV_LPC_GAIN_LOW_THRES ), down_scale_Q30 );
down_scale_Q30 = SKP_LSHIFT( down_scale_Q30, LOG2_INV_LPC_GAIN_HIGH_THRES );
rand_Gain_Q15 = SKP_RSHIFT( SKP_SMULWB( down_scale_Q30, rand_Gain_Q15 ), 14 );
}
}
rand_seed = psPLC->rand_seed;
lag = SKP_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
psDec->sLTP_buf_idx = psDec->frame_length;
/***************************/
/* LTP synthesis filtering */
/***************************/
sig_Q10_ptr = sig_Q10;
for( k = 0; k < NB_SUBFR; k++ ) {
/* Setup pointer */
pred_lag_ptr = &psDec->sLTP_Q16[ psDec->sLTP_buf_idx - lag + LTP_ORDER / 2 ];
for( i = 0; i < psDec->subfr_length; i++ ) {
rand_seed = SKP_RAND( rand_seed );
idx = SKP_RSHIFT( rand_seed, 25 ) & RAND_BUF_MASK;
/* Unrolled loop */
LTP_pred_Q14 = SKP_SMULWB( pred_lag_ptr[ 0 ], B_Q14[ 0 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -1 ], B_Q14[ 1 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -2 ], B_Q14[ 2 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -3 ], B_Q14[ 3 ] );
LTP_pred_Q14 = SKP_SMLAWB( LTP_pred_Q14, pred_lag_ptr[ -4 ], B_Q14[ 4 ] );
pred_lag_ptr++;
/* Generate LPC residual */
LPC_exc_Q10 = SKP_LSHIFT( SKP_SMULWB( rand_ptr[ idx ], rand_scale_Q14 ), 2 ); /* Random noise part */
LPC_exc_Q10 = SKP_ADD32( LPC_exc_Q10, SKP_RSHIFT_ROUND( LTP_pred_Q14, 4 ) ); /* Harmonic part */
/* Update states */
psDec->sLTP_Q16[ psDec->sLTP_buf_idx ] = SKP_LSHIFT( LPC_exc_Q10, 6 );
psDec->sLTP_buf_idx++;
/* Save LPC residual */
sig_Q10_ptr[ i ] = LPC_exc_Q10;
}
sig_Q10_ptr += psDec->subfr_length;
/* Gradually reduce LTP gain */
for( j = 0; j < LTP_ORDER; j++ ) {
B_Q14[ j ] = SKP_RSHIFT( SKP_SMULBB( harm_Gain_Q15, B_Q14[ j ] ), 15 );
}
/* Gradually reduce excitation gain */
rand_scale_Q14 = SKP_RSHIFT( SKP_SMULBB( rand_scale_Q14, rand_Gain_Q15 ), 15 );
/* Slowly increase pitch lag */
psPLC->pitchL_Q8 += SKP_SMULWB( psPLC->pitchL_Q8, PITCH_DRIFT_FAC_Q16 );
psPLC->pitchL_Q8 = SKP_min_32( psPLC->pitchL_Q8, SKP_LSHIFT( SKP_SMULBB( MAX_PITCH_LAG_MS, psDec->fs_kHz ), 8 ) );
lag = SKP_RSHIFT_ROUND( psPLC->pitchL_Q8, 8 );
}
/***************************/
/* LPC synthesis filtering */
/***************************/
sig_Q10_ptr = sig_Q10;
/* Preload LPC coeficients to array on stack. Gives small performance gain */
SKP_memcpy( A_Q12_tmp, psPLC->prevLPC_Q12, psDec->LPC_order * sizeof( SKP_int16 ) );
SKP_assert( psDec->LPC_order >= 10 ); /* check that unrolling works */
for( k = 0; k < NB_SUBFR; k++ ) {
for( i = 0; i < psDec->subfr_length; i++ ){
/* unrolled */
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ 0 ] ); /* read two coefficients at once */
LPC_pred_Q10 = SKP_SMULWB( psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], Atmp );
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ 2 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], Atmp );
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ 4 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], Atmp );
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ 6 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], Atmp );
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ 8 ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], Atmp );
for( j = 10 ; j < psDec->LPC_order ; j+=2 ) {
Atmp = *( ( SKP_int32* )&A_Q12_tmp[ j ] );
LPC_pred_Q10 = SKP_SMLAWB( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 1 - j ], Atmp );
LPC_pred_Q10 = SKP_SMLAWT( LPC_pred_Q10, psDec->sLPC_Q14[ MAX_LPC_ORDER + i - 2 - j ], Atmp );
}
/* Add prediction to LPC residual */
sig_Q10_ptr[ i ] = SKP_ADD32( sig_Q10_ptr[ i ], LPC_pred_Q10 );
/* Update states */
psDec->sLPC_Q14[ MAX_LPC_ORDER + i ] = SKP_LSHIFT( sig_Q10_ptr[ i ], 4 );
}
sig_Q10_ptr += psDec->subfr_length;
/* Update LPC filter state */
SKP_memcpy( psDec->sLPC_Q14, &psDec->sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( SKP_int32 ) );
}
/* Scale with Gain */
for( i = 0; i < psDec->frame_length; i++ ) {
signal[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT_ROUND( SKP_SMULWW( sig_Q10[ i ], psPLC->prevGain_Q16[ NB_SUBFR - 1 ] ), 10 ) );
}
/**************************************/
/* Update states */
/**************************************/
psPLC->rand_seed = rand_seed;
psPLC->randScale_Q14 = rand_scale_Q14;
for( i = 0; i < NB_SUBFR; i++ ) {
psDecCtrl->pitchL[ i ] = lag;
}
}
void SKP_Silk_resampler_private_up2_HQ(
SKP_int32 *S, /* I/O: Resampler state [ 6 ] */
SKP_int16 *out, /* O: Output signal [ 2 * len ] */
const SKP_int16 *in, /* I: Input signal [ len ] */
SKP_int32 len /* I: Number of INPUT samples */
)
{
SKP_int32 k;
SKP_int32 in32, out32_1, out32_2, Y, X;
SKP_assert( SKP_Silk_resampler_up2_hq_0[ 0 ] > 0 );
SKP_assert( SKP_Silk_resampler_up2_hq_0[ 1 ] < 0 );
SKP_assert( SKP_Silk_resampler_up2_hq_1[ 0 ] > 0 );
SKP_assert( SKP_Silk_resampler_up2_hq_1[ 1 ] < 0 );
/* Internal variables and state are in Q10 format */
for( k = 0; k < len; k++ ) {
/* Convert to Q10 */
in32 = SKP_LSHIFT( (SKP_int32)in[ k ], 10 );
/* First all-pass section for even output sample */
Y = SKP_SUB32( in32, S[ 0 ] );
X = SKP_SMULWB( Y, SKP_Silk_resampler_up2_hq_0[ 0 ] );
out32_1 = SKP_ADD32( S[ 0 ], X );
S[ 0 ] = SKP_ADD32( in32, X );
/* Second all-pass section for even output sample */
Y = SKP_SUB32( out32_1, S[ 1 ] );
X = SKP_SMLAWB( Y, Y, SKP_Silk_resampler_up2_hq_0[ 1 ] );
out32_2 = SKP_ADD32( S[ 1 ], X );
S[ 1 ] = SKP_ADD32( out32_1, X );
/* Biquad notch filter */
out32_2 = SKP_SMLAWB( out32_2, S[ 5 ], SKP_Silk_resampler_up2_hq_notch[ 2 ] );
out32_2 = SKP_SMLAWB( out32_2, S[ 4 ], SKP_Silk_resampler_up2_hq_notch[ 1 ] );
out32_1 = SKP_SMLAWB( out32_2, S[ 4 ], SKP_Silk_resampler_up2_hq_notch[ 0 ] );
S[ 5 ] = SKP_SUB32( out32_2, S[ 5 ] );
/* Apply gain in Q15, convert back to int16 and store to output */
out[ 2 * k ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT32(
SKP_SMLAWB( 256, out32_1, SKP_Silk_resampler_up2_hq_notch[ 3 ] ), 9 ) );
/* First all-pass section for odd output sample */
Y = SKP_SUB32( in32, S[ 2 ] );
X = SKP_SMULWB( Y, SKP_Silk_resampler_up2_hq_1[ 0 ] );
out32_1 = SKP_ADD32( S[ 2 ], X );
S[ 2 ] = SKP_ADD32( in32, X );
/* Second all-pass section for odd output sample */
Y = SKP_SUB32( out32_1, S[ 3 ] );
X = SKP_SMLAWB( Y, Y, SKP_Silk_resampler_up2_hq_1[ 1 ] );
out32_2 = SKP_ADD32( S[ 3 ], X );
S[ 3 ] = SKP_ADD32( out32_1, X );
/* Biquad notch filter */
out32_2 = SKP_SMLAWB( out32_2, S[ 4 ], SKP_Silk_resampler_up2_hq_notch[ 2 ] );
out32_2 = SKP_SMLAWB( out32_2, S[ 5 ], SKP_Silk_resampler_up2_hq_notch[ 1 ] );
out32_1 = SKP_SMLAWB( out32_2, S[ 5 ], SKP_Silk_resampler_up2_hq_notch[ 0 ] );
S[ 4 ] = SKP_SUB32( out32_2, S[ 4 ] );
/* Apply gain in Q15, convert back to int16 and store to output */
out[ 2 * k + 1 ] = (SKP_int16)SKP_SAT16( SKP_RSHIFT32(
SKP_SMLAWB( 256, out32_1, SKP_Silk_resampler_up2_hq_notch[ 3 ] ), 9 ) );
}
}
/* Find pitch lags */
void SKP_Silk_find_pitch_lags_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O encoder state */
SKP_Silk_encoder_control_FIX *psEncCtrl, /* I/O encoder control */
SKP_int16 res[], /* O residual */
const SKP_int16 x[] /* I Speech signal */
)
{
SKP_Silk_predict_state_FIX *psPredSt = &psEnc->sPred;
SKP_int buf_len, i, scale;
SKP_int32 thrhld_Q15, res_nrg;
const SKP_int16 *x_buf, *x_buf_ptr;
SKP_int16 Wsig[ FIND_PITCH_LPC_WIN_MAX ], *Wsig_ptr;
SKP_int32 auto_corr[ MAX_FIND_PITCH_LPC_ORDER + 1 ];
SKP_int16 rc_Q15[ MAX_FIND_PITCH_LPC_ORDER ];
SKP_int32 A_Q24[ MAX_FIND_PITCH_LPC_ORDER ];
SKP_int32 FiltState[ MAX_FIND_PITCH_LPC_ORDER ];
SKP_int16 A_Q12[ MAX_FIND_PITCH_LPC_ORDER ];
/******************************************/
/* Setup buffer lengths etc based on Fs */
/******************************************/
buf_len = SKP_ADD_LSHIFT( psEnc->sCmn.la_pitch, psEnc->sCmn.frame_length, 1 );
/* Safty check */
SKP_assert( buf_len >= psPredSt->pitch_LPC_win_length );
x_buf = x - psEnc->sCmn.frame_length;
/*************************************/
/* Estimate LPC AR coefficients */
/*************************************/
/* Calculate windowed signal */
/* First LA_LTP samples */
x_buf_ptr = x_buf + buf_len - psPredSt->pitch_LPC_win_length;
Wsig_ptr = Wsig;
SKP_Silk_apply_sine_window_new( Wsig_ptr, x_buf_ptr, 1, psEnc->sCmn.la_pitch );
/* Middle un - windowed samples */
Wsig_ptr += psEnc->sCmn.la_pitch;
x_buf_ptr += psEnc->sCmn.la_pitch;
SKP_memcpy( Wsig_ptr, x_buf_ptr, ( psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 ) ) * sizeof( SKP_int16 ) );
/* Last LA_LTP samples */
Wsig_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 );
x_buf_ptr += psPredSt->pitch_LPC_win_length - SKP_LSHIFT( psEnc->sCmn.la_pitch, 1 );
SKP_Silk_apply_sine_window_new( Wsig_ptr, x_buf_ptr, 2, psEnc->sCmn.la_pitch );
/* Calculate autocorrelation sequence */
SKP_Silk_autocorr( auto_corr, &scale, Wsig, psPredSt->pitch_LPC_win_length, psEnc->sCmn.pitchEstimationLPCOrder + 1 );
/* Add white noise, as fraction of energy */
auto_corr[ 0 ] = SKP_SMLAWB( auto_corr[ 0 ], auto_corr[ 0 ], SKP_FIX_CONST( FIND_PITCH_WHITE_NOISE_FRACTION, 16 ) );
/* Calculate the reflection coefficients using schur */
res_nrg = SKP_Silk_schur( rc_Q15, auto_corr, psEnc->sCmn.pitchEstimationLPCOrder );
/* Prediction gain */
psEncCtrl->predGain_Q16 = SKP_DIV32_varQ( auto_corr[ 0 ], SKP_max_int( res_nrg, 1 ), 16 );
/* Convert reflection coefficients to prediction coefficients */
SKP_Silk_k2a( A_Q24, rc_Q15, psEnc->sCmn.pitchEstimationLPCOrder );
/* Convert From 32 bit Q24 to 16 bit Q12 coefs */
for( i = 0; i < psEnc->sCmn.pitchEstimationLPCOrder; i++ ) {
A_Q12[ i ] = ( SKP_int16 )SKP_SAT16( SKP_RSHIFT( A_Q24[ i ], 12 ) );
}
/* Do BWE */
SKP_Silk_bwexpander( A_Q12, psEnc->sCmn.pitchEstimationLPCOrder, SKP_FIX_CONST( FIND_PITCH_BANDWITH_EXPANSION, 16 ) );
/*****************************************/
/* LPC analysis filtering */
/*****************************************/
SKP_memset( FiltState, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int32 ) ); /* Not really necessary, but Valgrind will complain otherwise */
SKP_Silk_MA_Prediction( x_buf, A_Q12, FiltState, res, buf_len, psEnc->sCmn.pitchEstimationLPCOrder );
SKP_memset( res, 0, psEnc->sCmn.pitchEstimationLPCOrder * sizeof( SKP_int16 ) );
/* Threshold for pitch estimator */
thrhld_Q15 = SKP_FIX_CONST( 0.45, 15 );
thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( -0.004, 15 ), psEnc->sCmn.pitchEstimationLPCOrder );
thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( -0.1, 7 ), psEnc->speech_activity_Q8 );
thrhld_Q15 = SKP_SMLABB( thrhld_Q15, SKP_FIX_CONST( 0.15, 15 ), psEnc->sCmn.prev_sigtype );
thrhld_Q15 = SKP_SMLAWB( thrhld_Q15, SKP_FIX_CONST( -0.1, 16 ), psEncCtrl->input_tilt_Q15 );
thrhld_Q15 = SKP_SAT16( thrhld_Q15 );
/*****************************************/
/* Call pitch estimator */
/*****************************************/
psEncCtrl->sCmn.sigtype = SKP_Silk_pitch_analysis_core( res, psEncCtrl->sCmn.pitchL, &psEncCtrl->sCmn.lagIndex,
&psEncCtrl->sCmn.contourIndex, &psEnc->LTPCorr_Q15, psEnc->sCmn.prevLag, psEnc->sCmn.pitchEstimationThreshold_Q16,
( SKP_int16 )thrhld_Q15, psEnc->sCmn.fs_kHz, psEnc->sCmn.pitchEstimationComplexity, SKP_FALSE );
}
