opus_int silk_InitEncoder( /* O Returns error code */
void *encState, /* I/O State */
int arch, /* I Run-time architecture */
silk_EncControlStruct *encStatus /* O Encoder Status */
)
{
silk_encoder *psEnc;
opus_int n, ret = SILK_NO_ERROR;
psEnc = (silk_encoder *)encState;
/* Reset encoder */
silk_memset( psEnc, 0, sizeof( silk_encoder ) );
for( n = 0; n < ENCODER_NUM_CHANNELS; n++ ) {
if( ret += silk_init_encoder( &psEnc->state_Fxx[ n ], arch ) ) {
silk_assert( 0 );
}
}
psEnc->nChannelsAPI = 1;
psEnc->nChannelsInternal = 1;
/* Read control structure */
if( ret += silk_QueryEncoder( encState, encStatus ) ) {
silk_assert( 0 );
}
return ret;
}
/* Compute quantization errors for an LPC_order element input vector for a VQ codebook */
void silk_NLSF_VQ(
opus_int32 err_Q26[], /* O Quantization errors [K] */
const opus_int16 in_Q15[], /* I Input vectors to be quantized [LPC_order] */
const opus_uint8 pCB_Q8[], /* I Codebook vectors [K*LPC_order] */
const opus_int K, /* I Number of codebook vectors */
const opus_int LPC_order /* I Number of LPCs */
)
{
opus_int i, m;
opus_int32 diff_Q15, sum_error_Q30, sum_error_Q26;
silk_assert( LPC_order <= 16 );
silk_assert( ( LPC_order & 1 ) == 0 );
/* Loop over codebook */
for( i = 0; i < K; i++ ) {
sum_error_Q26 = 0;
for( m = 0; m < LPC_order; m += 2 ) {
/* Compute weighted squared quantization error for index m */
diff_Q15 = silk_SUB_LSHIFT32( in_Q15[ m ], (opus_int32)*pCB_Q8++, 7 ); /* range: [ -32767 : 32767 ]*/
sum_error_Q30 = silk_SMULBB( diff_Q15, diff_Q15 );
/* Compute weighted squared quantization error for index m + 1 */
diff_Q15 = silk_SUB_LSHIFT32( in_Q15[m + 1], (opus_int32)*pCB_Q8++, 7 ); /* range: [ -32767 : 32767 ]*/
sum_error_Q30 = silk_SMLABB( sum_error_Q30, diff_Q15, diff_Q15 );
sum_error_Q26 = silk_ADD_RSHIFT32( sum_error_Q26, sum_error_Q30, 4 );
silk_assert( sum_error_Q26 >= 0 );
silk_assert( sum_error_Q30 >= 0 );
}
err_Q26[ i ] = sum_error_Q26;
}
}
static OPUS_INLINE void silk_LDL_FLP(
silk_float *A, /* I/O Pointer to Symetric Square Matrix */
opus_int M, /* I Size of Matrix */
silk_float *L, /* I/O Pointer to Square Upper triangular Matrix */
silk_float *Dinv /* I/O Pointer to vector holding the inverse diagonal elements of D */
)
{
opus_int i, j, k, loop_count, err = 1;
silk_float *ptr1, *ptr2;
double temp, diag_min_value;
silk_float v[ MAX_MATRIX_SIZE ] = { 0 }, D[ MAX_MATRIX_SIZE ]; /* temp arrays*/
silk_assert(M <= MAX_MATRIX_SIZE);
diag_min_value = FIND_LTP_COND_FAC * 0.5f * (A[ 0 ] + A[ M * M - 1 ]);
for(loop_count = 0; loop_count < M && err == 1; loop_count++) {
err = 0;
for(j = 0; j < M; j++) {
ptr1 = matrix_adr(L, j, 0, M);
temp = matrix_ptr(A, j, j, M); /* element in row j column j*/
for(i = 0; i < j; i++) {
v[ i ] = ptr1[ i ] * D[ i ];
temp -= ptr1[ i ] * v[ i ];
}
if(temp < diag_min_value) {
/* Badly conditioned matrix: add white noise and run again */
temp = (loop_count + 1) * diag_min_value - temp;
for(i = 0; i < M; i++) {
matrix_ptr(A, i, i, M) += (silk_float)temp;
}
err = 1;
break;
}
D[ j ] = (silk_float)temp;
Dinv[ j ] = (silk_float)(1.0f / temp);
matrix_ptr(L, j, j, M) = 1.0f;
ptr1 = matrix_adr(A, j, 0, M);
ptr2 = matrix_adr(L, j + 1, 0, M);
for(i = j + 1; i < M; i++) {
temp = 0.0;
for(k = 0; k < j; k++) {
temp += ptr2[ k ] * v[ k ];
}
matrix_ptr(L, i, j, M) = (silk_float)((ptr1[ i ] - temp) * Dinv[ j ]);
ptr2 += M; /* go to next column*/
}
}
}
silk_assert(err == 0);
}
/* 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 */
silk_assert( ( order & 1 ) == 0 );
silk_assert( 2 * QS - QC >= 0 );
/* Loop over samples */
for( n = 0; n < length; n++ ) {
tmp1_QS = silk_LSHIFT32( (opus_int32)input[ n ], QS );
/* Loop over allpass sections */
for( i = 0; i < order; i += 2 ) {
/* Output of allpass section */
tmp2_QS = silk_SMLAWB( state_QS[ i ], state_QS[ i + 1 ] - tmp1_QS, warping_Q16 );
state_QS[ i ] = tmp1_QS;
corr_QC[ i ] += silk_RSHIFT64( silk_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
/* Output of allpass section */
tmp1_QS = silk_SMLAWB( state_QS[ i + 1 ], state_QS[ i + 2 ] - tmp2_QS, warping_Q16 );
state_QS[ i + 1 ] = tmp2_QS;
corr_QC[ i + 1 ] += silk_RSHIFT64( silk_SMULL( tmp2_QS, state_QS[ 0 ] ), 2 * QS - QC );
}
state_QS[ order ] = tmp1_QS;
corr_QC[ order ] += silk_RSHIFT64( silk_SMULL( tmp1_QS, state_QS[ 0 ] ), 2 * QS - QC );
}
lsh = silk_CLZ64( corr_QC[ 0 ] ) - 35;
lsh = silk_LIMIT( lsh, -12 - QC, 30 - QC );
*scale = -( QC + lsh );
silk_assert( *scale >= -30 && *scale <= 12 );
if( lsh >= 0 ) {
for( i = 0; i < order + 1; i++ ) {
corr[ i ] = (opus_int32)silk_CHECK_FIT32( silk_LSHIFT64( corr_QC[ i ], lsh ) );
}
} else {
for( i = 0; i < order + 1; i++ ) {
corr[ i ] = (opus_int32)silk_CHECK_FIT32( silk_RSHIFT64( corr_QC[ i ], -lsh ) );
}
}
silk_assert( corr_QC[ 0 ] >= 0 ); /* If breaking, decrease QC*/
}
/* Residual energy: nrg = wxx - 2 * wXx * c + c' * wXX * c */
silk_float silk_residual_energy_covar_FLP( /* O Weighted residual energy */
const silk_float *c, /* I Filter coefficients */
silk_float *wXX, /* I/O Weighted correlation matrix, reg. out */
const silk_float *wXx, /* I Weighted correlation vector */
const silk_float wxx, /* I Weighted correlation value */
const opus_int D /* I Dimension */
)
{
opus_int i, j, k;
silk_float tmp, nrg = 0.0f, regularization;
/* Safety checks */
silk_assert( D >= 0 );
regularization = REGULARIZATION_FACTOR * ( wXX[ 0 ] + wXX[ D * D - 1 ] );
for( k = 0; k < MAX_ITERATIONS_RESIDUAL_NRG; k++ ) {
nrg = wxx;
tmp = 0.0f;
for( i = 0; i < D; i++ ) {
tmp += wXx[ i ] * c[ i ];
}
nrg -= 2.0f * tmp;
/* compute c' * wXX * c, assuming wXX is symmetric */
for( i = 0; i < D; i++ ) {
tmp = 0.0f;
for( j = i + 1; j < D; j++ ) {
tmp += matrix_c_ptr( wXX, i, j, D ) * c[ j ];
}
nrg += c[ i ] * ( 2.0f * tmp + matrix_c_ptr( wXX, i, i, D ) * c[ i ] );
}
if( nrg > 0 ) {
break;
} else {
/* Add white noise */
for( i = 0; i < D; i++ ) {
matrix_c_ptr( wXX, i, i, D ) += regularization;
}
/* Increase noise for next run */
regularization *= 2.0f;
}
}
if( k == MAX_ITERATIONS_RESIDUAL_NRG ) {
silk_assert( nrg == 0 );
nrg = 1.0f;
}
return nrg;
}
/* sum of squares of a silk_float array, with result as double */
double silk_energy_FLP(
const silk_float *data,
opus_int dataSize
)
{
opus_int i, dataSize4;
double result;
/* 4x unrolled loop */
result = 0.0;
dataSize4 = dataSize & 0xFFFC;
for( i = 0; i < dataSize4; i += 4 ) {
result += data[ i + 0 ] * (double)data[ i + 0 ] +
data[ i + 1 ] * (double)data[ i + 1 ] +
data[ i + 2 ] * (double)data[ i + 2 ] +
data[ i + 3 ] * (double)data[ i + 3 ];
}
/* add any remaining products */
for( ; i < dataSize; i++ ) {
result += data[ i ] * (double)data[ i ];
}
silk_assert( result >= 0.0 );
return result;
}
/* Shell decoder, operates on one shell code frame of 16 pulses */
void silk_shell_decoder(
opus_int *pulses0, /* O data: nonnegative pulse amplitudes */
ec_dec *psRangeDec, /* I/O Compressor data structure */
const opus_int pulses4 /* I number of pulses per pulse-subframe */
)
{
opus_int pulses3[ 2 ], pulses2[ 4 ], pulses1[ 8 ];
/* this function operates on one shell code frame of 16 pulses */
silk_assert( SHELL_CODEC_FRAME_LENGTH == 16 );
decode_split( &pulses3[ 0 ], &pulses3[ 1 ], psRangeDec, pulses4, silk_shell_code_table3 );
decode_split( &pulses2[ 0 ], &pulses2[ 1 ], psRangeDec, pulses3[ 0 ], silk_shell_code_table2 );
decode_split( &pulses1[ 0 ], &pulses1[ 1 ], psRangeDec, pulses2[ 0 ], silk_shell_code_table1 );
decode_split( &pulses0[ 0 ], &pulses0[ 1 ], psRangeDec, pulses1[ 0 ], silk_shell_code_table0 );
decode_split( &pulses0[ 2 ], &pulses0[ 3 ], psRangeDec, pulses1[ 1 ], silk_shell_code_table0 );
decode_split( &pulses1[ 2 ], &pulses1[ 3 ], psRangeDec, pulses2[ 1 ], silk_shell_code_table1 );
decode_split( &pulses0[ 4 ], &pulses0[ 5 ], psRangeDec, pulses1[ 2 ], silk_shell_code_table0 );
decode_split( &pulses0[ 6 ], &pulses0[ 7 ], psRangeDec, pulses1[ 3 ], silk_shell_code_table0 );
decode_split( &pulses2[ 2 ], &pulses2[ 3 ], psRangeDec, pulses3[ 1 ], silk_shell_code_table2 );
decode_split( &pulses1[ 4 ], &pulses1[ 5 ], psRangeDec, pulses2[ 2 ], silk_shell_code_table1 );
decode_split( &pulses0[ 8 ], &pulses0[ 9 ], psRangeDec, pulses1[ 4 ], silk_shell_code_table0 );
decode_split( &pulses0[ 10 ], &pulses0[ 11 ], psRangeDec, pulses1[ 5 ], silk_shell_code_table0 );
decode_split( &pulses1[ 6 ], &pulses1[ 7 ], psRangeDec, pulses2[ 3 ], silk_shell_code_table1 );
decode_split( &pulses0[ 12 ], &pulses0[ 13 ], psRangeDec, pulses1[ 6 ], silk_shell_code_table0 );
decode_split( &pulses0[ 14 ], &pulses0[ 15 ], psRangeDec, pulses1[ 7 ], silk_shell_code_table0 );
}
/* Calculates correlation vector X'*t */
void silk_corrVector_FIX(
const opus_int16 *x, /* I x vector [L + order - 1] used to form data matrix X */
const opus_int16 *t, /* I Target vector [L] */
const opus_int L, /* I Length of vectors */
const opus_int order, /* I Max lag for correlation */
opus_int32 *Xt, /* O Pointer to X'*t correlation vector [order] */
const opus_int rshifts /* I Right shifts of correlations */
)
{
opus_int lag, i;
const opus_int16 *ptr1, *ptr2;
opus_int32 inner_prod;
ptr1 = &x[ order - 1 ]; /* Points to first sample of column 0 of X: X[:,0] */
ptr2 = t;
/* Calculate X'*t */
if( rshifts > 0 ) {
/* Right shifting used */
for( lag = 0; lag < order; lag++ ) {
inner_prod = 0;
for( i = 0; i < L; i++ ) {
inner_prod += silk_RSHIFT32( silk_SMULBB( ptr1[ i ], ptr2[i] ), rshifts );
}
Xt[ lag ] = inner_prod; /* X[:,lag]'*t */
ptr1--; /* Go to next column of X */
}
} else {
silk_assert( rshifts == 0 );
for( lag = 0; lag < order; lag++ ) {
Xt[ lag ] = silk_inner_prod_aligned( ptr1, ptr2, L ); /* X[:,lag]'*t */
ptr1--; /* Go to next column of X */
}
}
}
/* Interpolate two vectors */
void silk_interpolate(
opus_int16 xi[ MAX_LPC_ORDER ], /* O interpolated vector */
const opus_int16 x0[ MAX_LPC_ORDER ], /* I first vector */
const opus_int16 x1[ MAX_LPC_ORDER ], /* I second vector */
const opus_int ifact_Q2, /* I interp. factor, weight on 2nd vector */
const opus_int d /* I number of parameters */
)
{
opus_int i;
silk_assert( ifact_Q2 >= 0 );
silk_assert( ifact_Q2 <= 4 );
for( i = 0; i < d; i++ ) {
xi[ i ] = (opus_int16)silk_ADD_RSHIFT( x0[ i ], silk_SMULBB( x1[ i ] - x0[ i ], ifact_Q2 ), 2 );
}
}
/* This function is only used by the fixed-point build */
void silk_insertion_sort_decreasing_int16(
opus_int16 *a, /* I/O Unsorted / Sorted vector */
opus_int *idx, /* O Index vector for the sorted elements */
const opus_int L, /* I Vector length */
const opus_int K /* I Number of correctly sorted positions */
)
{
opus_int i, j;
opus_int value;
/* Safety checks */
silk_assert( K > 0 );
silk_assert( L > 0 );
silk_assert( L >= K );
/* Write start indices in index vector */
for( i = 0; i < K; i++ ) {
idx[ i ] = i;
}
/* Sort vector elements by value, decreasing order */
for( i = 1; i < K; i++ ) {
value = a[ i ];
for( j = i - 1; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
a[ j + 1 ] = a[ j ]; /* Shift value */
idx[ j + 1 ] = idx[ j ]; /* Shift index */
}
a[ j + 1 ] = value; /* Write value */
idx[ j + 1 ] = i; /* Write index */
}
/* If less than L values are asked for, check the remaining values, */
/* but only spend CPU to ensure that the K first values are correct */
for( i = K; i < L; i++ ) {
value = a[ i ];
if( value > a[ K - 1 ] ) {
for( j = K - 2; ( j >= 0 ) && ( value > a[ j ] ); j-- ) {
a[ j + 1 ] = a[ j ]; /* Shift value */
idx[ j + 1 ] = idx[ j ]; /* Shift index */
}
a[ j + 1 ] = value; /* Write value */
idx[ j + 1 ] = i; /* Write index */
}
}
}
void silk_LPC_analysis_filter(
opus_int16 *out, /* O Output signal */
const opus_int16 *in, /* I Input signal */
const opus_int16 *B, /* I MA prediction coefficients, Q12 [order] */
const opus_int32 len, /* I Signal length */
const opus_int32 d /* I Filter order */
)
{
opus_int ix, j;
opus_int32 out32_Q12, out32;
const opus_int16 *in_ptr;
silk_assert( d >= 6 );
silk_assert( (d & 1) == 0 );
silk_assert( d <= len );
for( ix = d; ix < len; ix++ ) {
in_ptr = &in[ ix - 1 ];
out32_Q12 = silk_SMULBB( in_ptr[ 0 ], B[ 0 ] );
/* Allowing wrap around so that two wraps can cancel each other. The rare
cases where the result wraps around can only be triggered by invalid streams*/
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -1 ], B[ 1 ] );
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -2 ], B[ 2 ] );
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -3 ], B[ 3 ] );
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -4 ], B[ 4 ] );
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -5 ], B[ 5 ] );
for( j = 6; j < d; j += 2 ) {
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -j ], B[ j ] );
out32_Q12 = silk_SMLABB_ovflw( out32_Q12, in_ptr[ -j - 1 ], B[ j + 1 ] );
}
/* Subtract prediction */
out32_Q12 = silk_SUB32_ovflw( silk_LSHIFT( (opus_int32)in_ptr[ 1 ], 12 ), out32_Q12 );
/* Scale to Q0 */
out32 = silk_RSHIFT_ROUND( out32_Q12, 12 );
/* Saturate output */
out[ ix ] = (opus_int16)silk_SAT16( out32 );
}
/* Set first d output samples to zero */
silk_memset( out, 0, d * sizeof( opus_int16 ) );
}
/* uses SMLAWB(), requiring armv5E and higher. */
opus_int32 silk_schur( /* O Returns residual energy */
opus_int16 *rc_Q15, /* O reflection coefficients [order] Q15 */
const opus_int32 *c, /* I correlations [order+1] */
const opus_int32 order /* I prediction order */
)
{
opus_int k, n, lz;
opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
opus_int32 Ctmp1, Ctmp2, rc_tmp_Q15;
silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );
/* Get number of leading zeros */
lz = 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 ] = silk_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 ] = silk_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 = -silk_DIV32_16( C[ k + 1 ][ 0 ], silk_max_32( silk_RSHIFT( C[ 0 ][ 1 ], 15 ), 1 ) );
/* Clip (shouldn't happen for properly conditioned inputs) */
rc_tmp_Q15 = silk_SAT16( rc_tmp_Q15 );
/* Store */
rc_Q15[ k ] = (opus_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 ] = silk_SMLAWB( Ctmp1, silk_LSHIFT( Ctmp2, 1 ), rc_tmp_Q15 );
C[ n ][ 1 ] = silk_SMLAWB( Ctmp2, silk_LSHIFT( Ctmp1, 1 ), rc_tmp_Q15 );
}
}
/* return residual energy */
return C[ 0 ][ 1 ];
}
/* Entropy code the mid/side quantization indices */
void silk_stereo_encode_pred(
ec_enc *psRangeEnc, /* I/O Compressor data structure */
opus_int8 ix[ 2 ][ 3 ] /* I Quantization indices */
)
{
opus_int n;
/* Entropy coding */
n = 5 * ix[ 0 ][ 2 ] + ix[ 1 ][ 2 ];
silk_assert( n < 25 );
ec_enc_icdf( psRangeEnc, n, silk_stereo_pred_joint_iCDF, 8 );
for( n = 0; n < 2; n++ ) {
silk_assert( ix[ n ][ 0 ] < 3 );
silk_assert( ix[ n ][ 1 ] < STEREO_QUANT_SUB_STEPS );
ec_enc_icdf( psRangeEnc, ix[ n ][ 0 ], silk_uniform3_iCDF, 8 );
ec_enc_icdf( psRangeEnc, ix[ n ][ 1 ], silk_uniform5_iCDF, 8 );
}
}
/* Uses SMULL(), available on armv4 */
opus_int32 silk_schur64( /* O returns residual energy */
opus_int32 rc_Q16[], /* O Reflection coefficients [order] Q16 */
const opus_int32 c[], /* I Correlations [order+1] */
opus_int32 order /* I Prediction order */
)
{
opus_int k, n;
opus_int32 C[ SILK_MAX_ORDER_LPC + 1 ][ 2 ];
opus_int32 Ctmp1_Q30, Ctmp2_Q30, rc_tmp_Q31;
silk_assert( order==6||order==8||order==10||order==12||order==14||order==16 );
/* Check for invalid input */
if( c[ 0 ] <= 0 ) {
silk_memset( rc_Q16, 0, order * sizeof( opus_int32 ) );
return 0;
}
for( k = 0; k < order + 1; k++ ) {
C[ k ][ 0 ] = C[ k ][ 1 ] = c[ k ];
}
for( k = 0; k < order; k++ ) {
/* Check that we won't be getting an unstable rc, otherwise stop here. */
if (silk_abs_int32(C[ k + 1 ][ 0 ]) >= C[ 0 ][ 1 ]) {
if ( C[ k + 1 ][ 0 ] > 0 ) {
rc_Q16[ k ] = -SILK_FIX_CONST( .99f, 16 );
} else {
rc_Q16[ k ] = SILK_FIX_CONST( .99f, 16 );
}
k++;
break;
}
/* Get reflection coefficient: divide two Q30 values and get result in Q31 */
rc_tmp_Q31 = silk_DIV32_varQ( -C[ k + 1 ][ 0 ], C[ 0 ][ 1 ], 31 );
/* Save the output */
rc_Q16[ k ] = silk_RSHIFT_ROUND( rc_tmp_Q31, 15 );
/* Update correlations */
for( n = 0; n < order - k; n++ ) {
Ctmp1_Q30 = C[ n + k + 1 ][ 0 ];
Ctmp2_Q30 = C[ n ][ 1 ];
/* Multiply and add the highest int32 */
C[ n + k + 1 ][ 0 ] = Ctmp1_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp2_Q30, 1 ), rc_tmp_Q31 );
C[ n ][ 1 ] = Ctmp2_Q30 + silk_SMMUL( silk_LSHIFT( Ctmp1_Q30, 1 ), rc_tmp_Q31 );
}
}
for(; k < order; k++ ) {
rc_Q16[ k ] = 0;
}
return silk_max_32( 1, C[ 0 ][ 1 ] );
}
/* 2 -> sine window from pi/2 to pi */
void silk_apply_sine_window_FLP(
silk_float px_win[], /* O Pointer to windowed signal */
const silk_float px[], /* I Pointer to input signal */
const opus_int win_type, /* I Selects a window type */
const opus_int length /* I Window length, multiple of 4 */
)
{
opus_int k;
silk_float freq, c, S0, S1;
silk_assert( win_type == 1 || win_type == 2 );
/* Length must be multiple of 4 */
silk_assert( ( length & 3 ) == 0 );
freq = PI / ( length + 1 );
/* Approximation of 2 * cos(f) */
c = 2.0f - freq * freq;
/* Initialize state */
if( win_type < 2 ) {
/* Start from 0 */
S0 = 0.0f;
/* Approximation of sin(f) */
S1 = freq;
} else {
/* Start from 1 */
S0 = 1.0f;
/* Approximation of cos(f) */
S1 = 0.5f * c;
}
/* Uses the recursive equation: sin(n*f) = 2 * cos(f) * sin((n-1)*f) - sin((n-2)*f) */
/* 4 samples at a time */
for( k = 0; k < length; k += 4 ) {
px_win[ k + 0 ] = px[ k + 0 ] * 0.5f * ( S0 + S1 );
px_win[ k + 1 ] = px[ k + 1 ] * S1;
S0 = c * S1 - S0;
px_win[ k + 2 ] = px[ k + 2 ] * 0.5f * ( S1 + S0 );
px_win[ k + 3 ] = px[ k + 3 ] * S0;
S1 = c * S0 - S1;
}
}
/* Prefilter for finding Quantizer input signal */
static OPUS_INLINE void silk_prefilt_FIX(
silk_prefilter_state_FIX *P, /* I/O state */
opus_int32 st_res_Q12[], /* I short term residual signal */
opus_int32 xw_Q3[], /* O prefiltered signal */
opus_int32 HarmShapeFIRPacked_Q12, /* I Harmonic shaping coeficients */
opus_int Tilt_Q14, /* I Tilt shaping coeficient */
opus_int32 LF_shp_Q14, /* I Low-frequancy shaping coeficients */
opus_int lag, /* I Lag for harmonic shaping */
opus_int length /* I Length of signals */
) {
opus_int i, idx, LTP_shp_buf_idx;
opus_int32 n_LTP_Q12, n_Tilt_Q10, n_LF_Q10;
opus_int32 sLF_MA_shp_Q12, sLF_AR_shp_Q12;
opus_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 */
silk_assert(HARM_SHAPE_FIR_TAPS == 3);
idx = lag + LTP_shp_buf_idx;
n_LTP_Q12 = silk_SMULBB(LTP_shp_buf[(idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK],
HarmShapeFIRPacked_Q12);
n_LTP_Q12 = silk_SMLABT(n_LTP_Q12,
LTP_shp_buf[(idx - HARM_SHAPE_FIR_TAPS / 2) & LTP_MASK],
HarmShapeFIRPacked_Q12);
n_LTP_Q12 = silk_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 = silk_SMULWB(sLF_AR_shp_Q12, Tilt_Q14);
n_LF_Q10 = silk_SMLAWB(silk_SMULWT(sLF_AR_shp_Q12, LF_shp_Q14), sLF_MA_shp_Q12, LF_shp_Q14);
sLF_AR_shp_Q12 = silk_SUB32(st_res_Q12[i], silk_LSHIFT(n_Tilt_Q10, 2));
sLF_MA_shp_Q12 = silk_SUB32(sLF_AR_shp_Q12, silk_LSHIFT(n_LF_Q10, 2));
LTP_shp_buf_idx = (LTP_shp_buf_idx - 1) & LTP_MASK;
LTP_shp_buf[LTP_shp_buf_idx] = (opus_int16) silk_SAT16(
silk_RSHIFT_ROUND(sLF_MA_shp_Q12, 12));
xw_Q3[i] = silk_RSHIFT_ROUND(silk_SUB32(sLF_MA_shp_Q12, n_LTP_Q12), 9);
}
/* 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;
}
/* Input and output sampling rate are at most 48000 Hz */
opus_int silk_resampler(
silk_resampler_state_struct *S, /* I/O Resampler state */
opus_int16 out[], /* O Output signal */
const opus_int16 in[], /* I Input signal */
opus_int32 inLen /* I Number of input samples */
)
{
opus_int nSamples;
/* Need at least 1 ms of input data */
silk_assert( inLen >= S->Fs_in_kHz );
/* Delay can't exceed the 1 ms of buffering */
silk_assert( S->inputDelay <= S->Fs_in_kHz );
nSamples = S->Fs_in_kHz - S->inputDelay;
/* Copy to delay buffer */
silk_memcpy( &S->delayBuf[ S->inputDelay ], in, nSamples * sizeof( opus_int16 ) );
switch( S->resampler_function ) {
case USE_silk_resampler_private_up2_HQ_wrapper:
silk_resampler_private_up2_HQ_wrapper( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_up2_HQ_wrapper( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
case USE_silk_resampler_private_IIR_FIR:
silk_resampler_private_IIR_FIR( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_IIR_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
case USE_silk_resampler_private_down_FIR:
silk_resampler_private_down_FIR( S, out, S->delayBuf, S->Fs_in_kHz );
silk_resampler_private_down_FIR( S, &out[ S->Fs_out_kHz ], &in[ nSamples ], inLen - S->Fs_in_kHz );
break;
default:
silk_memcpy( out, S->delayBuf, S->Fs_in_kHz * sizeof( opus_int16 ) );
silk_memcpy( &out[ S->Fs_out_kHz ], &in[ nSamples ], ( inLen - S->Fs_in_kHz ) * sizeof( opus_int16 ) );
}
/* Copy to delay buffer */
silk_memcpy( S->delayBuf, &in[ inLen - S->inputDelay ], S->inputDelay * sizeof( opus_int16 ) );
return 0;
}
/* Helper function, interpolates the filter taps */
static OPUS_INLINE void silk_LP_interpolate_filter_taps(
opus_int32 B_Q28[ TRANSITION_NB ],
opus_int32 A_Q28[ TRANSITION_NA ],
const opus_int ind,
const opus_int32 fac_Q16
)
{
opus_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 ] = silk_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 ] = silk_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 */
silk_assert( fac_Q16 - ( 1 << 16 ) == silk_SAT16( fac_Q16 - ( 1 << 16 ) ) );
/* Piece-wise linear interpolation of B and A */
for( nb = 0; nb < TRANSITION_NB; nb++ ) {
B_Q28[ nb ] = silk_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 - ( (opus_int32)1 << 16 ) );
}
for( na = 0; na < TRANSITION_NA; na++ ) {
A_Q28[ na ] = silk_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 - ( (opus_int32)1 << 16 ) );
}
}
} else {
silk_memcpy( B_Q28, silk_Transition_LP_B_Q28[ ind ], TRANSITION_NB * sizeof( opus_int32 ) );
silk_memcpy( A_Q28, silk_Transition_LP_A_Q28[ ind ], TRANSITION_NA * sizeof( opus_int32 ) );
}
} else {
silk_memcpy( B_Q28, silk_Transition_LP_B_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NB * sizeof( opus_int32 ) );
silk_memcpy( A_Q28, silk_Transition_LP_A_Q28[ TRANSITION_INT_NUM - 1 ], TRANSITION_NA * sizeof( opus_int32 ) );
}
}
void silk_LPC_analysis_filter_FLP(
silk_float r_LPC[], /* O LPC residual signal */
const silk_float PredCoef[], /* I LPC coefficients */
const silk_float s[], /* I Input signal */
const opus_int length, /* I Length of input signal */
const opus_int Order /* I LPC order */
)
{
silk_assert( Order <= length );
switch( Order ) {
case 6:
silk_LPC_analysis_filter6_FLP( r_LPC, PredCoef, s, length );
break;
case 8:
silk_LPC_analysis_filter8_FLP( r_LPC, PredCoef, s, length );
break;
case 10:
silk_LPC_analysis_filter10_FLP( r_LPC, PredCoef, s, length );
break;
case 12:
silk_LPC_analysis_filter12_FLP( r_LPC, PredCoef, s, length );
break;
case 16:
silk_LPC_analysis_filter16_FLP( r_LPC, PredCoef, s, length );
break;
default:
silk_assert( 0 );
break;
}
/* Set first Order output samples to zero */
silk_memset( r_LPC, 0, Order * sizeof( silk_float ) );
}
/*
* Prefilter for finding Quantizer input signal
*/
static OPUS_INLINE void silk_prefilt_FLP(
silk_prefilter_state_FLP *P, /* I/O state */
silk_float st_res[], /* I */
silk_float xw[], /* O */
silk_float *HarmShapeFIR, /* I */
silk_float Tilt, /* I */
silk_float LF_MA_shp, /* I */
silk_float LF_AR_shp, /* I */
opus_int lag, /* I */
opus_int length /* I */
)
{
opus_int i;
opus_int idx, LTP_shp_buf_idx;
silk_float n_Tilt, n_LF, n_LTP;
silk_float sLF_AR_shp, sLF_MA_shp;
silk_float *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 = P->sLF_AR_shp;
sLF_MA_shp = P->sLF_MA_shp;
for( i = 0; i < length; i++ ) {
if( lag > 0 ) {
silk_assert( HARM_SHAPE_FIR_TAPS == 3 );
idx = lag + LTP_shp_buf_idx;
n_LTP = LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 - 1) & LTP_MASK ] * HarmShapeFIR[ 0 ];
n_LTP += LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 ) & LTP_MASK ] * HarmShapeFIR[ 1 ];
n_LTP += LTP_shp_buf[ ( idx - HARM_SHAPE_FIR_TAPS / 2 + 1) & LTP_MASK ] * HarmShapeFIR[ 2 ];
} else {
n_LTP = 0;
}
n_Tilt = sLF_AR_shp * Tilt;
n_LF = sLF_AR_shp * LF_AR_shp + sLF_MA_shp * LF_MA_shp;
sLF_AR_shp = st_res[ i ] - n_Tilt;
sLF_MA_shp = sLF_AR_shp - n_LF;
LTP_shp_buf_idx = ( LTP_shp_buf_idx - 1 ) & LTP_MASK;
LTP_shp_buf[ LTP_shp_buf_idx ] = sLF_MA_shp;
xw[ i ] = sLF_MA_shp - n_LTP;
}
/* Copy temp variable back to state */
P->sLF_AR_shp = sLF_AR_shp;
P->sLF_MA_shp = sLF_MA_shp;
P->sLTP_shp_buf_idx = LTP_shp_buf_idx;
}
/* Deactivate by setting psEncC->mode = 0; */
void silk_LP_variable_cutoff(
silk_LP_state *psLP, /* I/O LP filter state */
opus_int16 *frame, /* I/O Low-pass filtered output signal */
const opus_int frame_length /* I Frame length */
)
{
opus_int32 B_Q28[ TRANSITION_NB ], A_Q28[ TRANSITION_NA ], fac_Q16 = 0;
opus_int ind = 0;
silk_assert( psLP->transition_frame_no >= 0 && psLP->transition_frame_no <= TRANSITION_FRAMES );
/* Run filter if needed */
if( psLP->mode != 0 ) {
/* Calculate index and interpolation factor for interpolation */
#if( TRANSITION_INT_STEPS == 64 )
fac_Q16 = silk_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 - 6 );
#else
fac_Q16 = silk_DIV32_16( silk_LSHIFT( TRANSITION_FRAMES - psLP->transition_frame_no, 16 ), TRANSITION_FRAMES );
#endif
ind = silk_RSHIFT( fac_Q16, 16 );
fac_Q16 -= silk_LSHIFT( ind, 16 );
silk_assert( ind >= 0 );
silk_assert( ind < TRANSITION_INT_NUM );
/* Interpolate filter coefficients */
silk_LP_interpolate_filter_taps( B_Q28, A_Q28, ind, fac_Q16 );
/* Update transition frame number for next frame */
psLP->transition_frame_no = silk_LIMIT( psLP->transition_frame_no + psLP->mode, 0, TRANSITION_FRAMES );
/* ARMA low-pass filtering */
silk_assert( TRANSITION_NB == 3 && TRANSITION_NA == 2 );
silk_biquad_alt( frame, B_Q28, A_Q28, psLP->In_LP_State, frame, frame_length, 1);
}
}
/* Processing of gains */
void silk_process_gains_FIX(
silk_encoder_state_FIX *psEnc, /* I/O Encoder state */
silk_encoder_control_FIX *psEncCtrl, /* I/O Encoder control */
opus_int condCoding /* I The type of conditional coding to use */
)
{
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 * silk_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
s_Q16 = -silk_sigm_Q15( silk_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 ] = silk_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 = silk_DIV32_16( silk_log2lin(
silk_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 = silk_SMULWW( ResNrg, InvMaxSqrVal_Q16 );
if( psEncCtrl->ResNrgQ[ k ] > 0 ) {
ResNrgPart = silk_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
} else {
if( ResNrgPart >= silk_RSHIFT( silk_int32_MAX, -psEncCtrl->ResNrgQ[ k ] ) ) {
ResNrgPart = silk_int32_MAX;
} else {
ResNrgPart = silk_LSHIFT( ResNrgPart, -psEncCtrl->ResNrgQ[ k ] );
}
}
gain = psEncCtrl->Gains_Q16[ k ];
gain_squared = silk_ADD_SAT32( ResNrgPart, silk_SMMUL( gain, gain ) );
if( gain_squared < silk_int16_MAX ) {
/* recalculate with higher precision */
gain_squared = silk_SMLAWW( silk_LSHIFT( ResNrgPart, 16 ), gain, gain );
silk_assert( gain_squared > 0 );
gain = silk_SQRT_APPROX( gain_squared ); /* Q8 */
gain = silk_min( gain, silk_int32_MAX >> 8 );
psEncCtrl->Gains_Q16[ k ] = silk_LSHIFT_SAT32( gain, 8 ); /* Q16 */
} else {
/* Find least-squares prediction gain for one signal based on another and quantize it */
opus_int32 silk_stereo_find_predictor( /* O Returns predictor in Q13 */
opus_int32 *ratio_Q14, /* O Ratio of residual and mid energies */
const opus_int16 x[], /* I Basis signal */
const opus_int16 y[], /* I Target signal */
opus_int32 mid_res_amp_Q0[], /* I/O Smoothed mid, residual norms */
opus_int length, /* I Number of samples */
opus_int smooth_coef_Q16 /* I Smoothing coefficient */
)
{
opus_int scale, scale1, scale2;
opus_int32 nrgx, nrgy, corr, pred_Q13, pred2_Q10;
/* Find predictor */
silk_sum_sqr_shift( &nrgx, &scale1, x, length );
silk_sum_sqr_shift( &nrgy, &scale2, y, length );
scale = silk_max_int( scale1, scale2 );
scale = scale + ( scale & 1 ); /* make even */
nrgy = silk_RSHIFT32( nrgy, scale - scale2 );
nrgx = silk_RSHIFT32( nrgx, scale - scale1 );
nrgx = silk_max_int( nrgx, 1 );
corr = silk_inner_prod_aligned_scale( x, y, scale, length );
pred_Q13 = silk_DIV32_varQ( corr, nrgx, 13 );
pred_Q13 = silk_LIMIT( pred_Q13, -(1 << 14), 1 << 14 );
pred2_Q10 = silk_SMULWB( pred_Q13, pred_Q13 );
/* Faster update for signals with large prediction parameters */
smooth_coef_Q16 = (opus_int)silk_max_int( smooth_coef_Q16, silk_abs( pred2_Q10 ) );
/* Smoothed mid and residual norms */
silk_assert( smooth_coef_Q16 < 32768 );
scale = silk_RSHIFT( scale, 1 );
mid_res_amp_Q0[ 0 ] = silk_SMLAWB( mid_res_amp_Q0[ 0 ], silk_LSHIFT( silk_SQRT_APPROX( nrgx ), scale ) - mid_res_amp_Q0[ 0 ],
smooth_coef_Q16 );
/* Residual energy = nrgy - 2 * pred * corr + pred^2 * nrgx */
nrgy = silk_SUB_LSHIFT32( nrgy, silk_SMULWB( corr, pred_Q13 ), 3 + 1 );
nrgy = silk_ADD_LSHIFT32( nrgy, silk_SMULWB( nrgx, pred2_Q10 ), 6 );
mid_res_amp_Q0[ 1 ] = silk_SMLAWB( mid_res_amp_Q0[ 1 ], silk_LSHIFT( silk_SQRT_APPROX( nrgy ), scale ) - mid_res_amp_Q0[ 1 ],
smooth_coef_Q16 );
/* Ratio of smoothed residual and mid norms */
*ratio_Q14 = silk_DIV32_varQ( mid_res_amp_Q0[ 1 ], silk_max( mid_res_amp_Q0[ 0 ], 1 ), 14 );
*ratio_Q14 = silk_LIMIT( *ratio_Q14, 0, 32767 );
return pred_Q13;
}
void silk_insertion_sort_increasing_all_values_int16(
opus_int16 *a, /* I/O Unsorted / Sorted vector */
const opus_int L /* I Vector length */
)
{
opus_int value;
opus_int i, j;
/* Safety checks */
silk_assert( L > 0 );
/* Sort vector elements by value, increasing order */
for( i = 1; i < L; i++ ) {
value = a[ i ];
for( j = i - 1; ( j >= 0 ) && ( value < a[ j ] ); j-- ) {
a[ j + 1 ] = a[ j ]; /* Shift value */
}
a[ j + 1 ] = value; /* Write value */
}
}
void silk_warped_LPC_analysis_filter_FIX(
opus_int32 state[], /* I/O State [order + 1] */
opus_int32 res_Q2[], /* O Residual signal [length] */
const opus_int16 coef_Q13[], /* I Coefficients [order] */
const opus_int16 input[], /* I Input signal [length] */
const opus_int16 lambda_Q16, /* I Warping factor */
const opus_int length, /* I Length of input signal */
const opus_int order /* I Filter order (even) */
)
{
opus_int n, i;
opus_int32 acc_Q11, tmp1, tmp2;
/* Order must be even */
silk_assert( ( order & 1 ) == 0 );
for( n = 0; n < length; n++ ) {
/* Output of lowpass section */
tmp2 = silk_SMLAWB( state[ 0 ], state[ 1 ], lambda_Q16 );
state[ 0 ] = silk_LSHIFT( input[ n ], 14 );
/* Output of allpass section */
tmp1 = silk_SMLAWB( state[ 1 ], state[ 2 ] - tmp2, lambda_Q16 );
state[ 1 ] = tmp2;
acc_Q11 = silk_RSHIFT( order, 1 );
acc_Q11 = silk_SMLAWB( acc_Q11, tmp2, coef_Q13[ 0 ] );
/* Loop over allpass sections */
for( i = 2; i < order; i += 2 ) {
/* Output of allpass section */
tmp2 = silk_SMLAWB( state[ i ], state[ i + 1 ] - tmp1, lambda_Q16 );
state[ i ] = tmp1;
acc_Q11 = silk_SMLAWB( acc_Q11, tmp1, coef_Q13[ i - 1 ] );
/* Output of allpass section */
tmp1 = silk_SMLAWB( state[ i + 1 ], state[ i + 2 ] - tmp2, lambda_Q16 );
state[ i + 1 ] = tmp2;
acc_Q11 = silk_SMLAWB( acc_Q11, tmp2, coef_Q13[ i ] );
}
state[ order ] = tmp1;
acc_Q11 = silk_SMLAWB( acc_Q11, tmp1, coef_Q13[ order - 1 ] );
res_Q2[ n ] = silk_LSHIFT( (opus_int32)input[ n ], 2 ) - silk_RSHIFT_ROUND( acc_Q11, 9 );
}
}
static void silk_warped_LPC_analysis_filter_FLP(
silk_float state[], /* I/O State [order + 1] */
silk_float res[], /* O Residual signal [length] */
const silk_float coef[], /* I Coefficients [order] */
const silk_float input[], /* I Input signal [length] */
const silk_float lambda, /* I Warping factor */
const opus_int length, /* I Length of input signal */
const opus_int order /* I Filter order (even) */
)
{
opus_int n, i;
silk_float acc, tmp1, tmp2;
/* Order must be even */
silk_assert( ( order & 1 ) == 0 );
for( n = 0; n < length; n++ ) {
/* Output of lowpass section */
tmp2 = state[ 0 ] + lambda * state[ 1 ];
state[ 0 ] = input[ n ];
/* Output of allpass section */
tmp1 = state[ 1 ] + lambda * ( state[ 2 ] - tmp2 );
state[ 1 ] = tmp2;
acc = coef[ 0 ] * tmp2;
/* Loop over allpass sections */
for( i = 2; i < order; i += 2 ) {
/* Output of allpass section */
tmp2 = state[ i ] + lambda * ( state[ i + 1 ] - tmp1 );
state[ i ] = tmp1;
acc += coef[ i - 1 ] * tmp1;
/* Output of allpass section */
tmp1 = state[ i + 1 ] + lambda * ( state[ i + 2 ] - tmp2 );
state[ i + 1 ] = tmp2;
acc += coef[ i ] * tmp2;
}
state[ order ] = tmp1;
acc += coef[ order - 1 ] * tmp1;
res[ n ] = input[ n ] - acc;
}
}
/* Solves Ax = b, assuming A is symmetric */
void silk_solve_LDL_FIX(
opus_int32 *A, /* I Pointer to symetric square matrix A */
opus_int M, /* I Size of matrix */
const opus_int32 *b, /* I Pointer to b vector */
opus_int32 *x_Q16 /* O Pointer to x solution vector */
)
{
VARDECL( opus_int32, L_Q16 );
opus_int32 Y[ MAX_MATRIX_SIZE ];
inv_D_t inv_D[ MAX_MATRIX_SIZE ];
SAVE_STACK;
silk_assert( M <= MAX_MATRIX_SIZE );
ALLOC( L_Q16, M * M, opus_int32 );
/***************************************************
Factorize A by LDL such that A = L*D*L',
where L is lower triangular with ones on diagonal
****************************************************/
silk_LDL_factorize_FIX( A, M, L_Q16, inv_D );
/****************************************************
* substitute D*L'*x = Y. ie:
L*D*L'*x = b => L*Y = b <=> Y = inv(L)*b
******************************************************/
silk_LS_SolveFirst_FIX( L_Q16, M, b, Y );
/****************************************************
D*L'*x = Y <=> L'*x = inv(D)*Y, because D is
diagonal just multiply with 1/d_i
****************************************************/
silk_LS_divide_Q16_FIX( Y, inv_D, M );
/****************************************************
x = inv(L') * inv(D) * Y
*****************************************************/
silk_LS_SolveLast_FIX( L_Q16, M, Y, x_Q16 );
RESTORE_STACK;
}
/* Autocorrelations for a warped frequency axis */
void silk_warped_autocorrelation_FLP(
silk_float *corr, /* O Result [order + 1] */
const silk_float *input, /* I Input data to correlate */
const silk_float warping, /* I Warping coefficient */
const opus_int length, /* I Length of input */
const opus_int order /* I Correlation order (even) */
)
{
opus_int n, i;
double tmp1, tmp2;
double state[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
double C[ MAX_SHAPE_LPC_ORDER + 1 ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 };
/* Order must be even */
silk_assert( ( order & 1 ) == 0 );
/* Loop over samples */
for( n = 0; n < length; n++ ) {
tmp1 = input[ n ];
/* Loop over allpass sections */
for( i = 0; i < order; i += 2 ) {
/* Output of allpass section */
tmp2 = state[ i ] + warping * ( state[ i + 1 ] - tmp1 );
state[ i ] = tmp1;
C[ i ] += state[ 0 ] * tmp1;
/* Output of allpass section */
tmp1 = state[ i + 1 ] + warping * ( state[ i + 2 ] - tmp2 );
state[ i + 1 ] = tmp2;
C[ i + 1 ] += state[ 0 ] * tmp2;
}
state[ order ] = tmp1;
C[ order ] += state[ 0 ] * tmp1;
}
/* Copy correlations in silk_float output format */
for( i = 0; i < order + 1; i++ ) {
corr[ i ] = ( silk_float )C[ i ];
}
}
/* Shell encoder, operates on one shell code frame of 16 pulses */
void silk_shell_encoder(
ec_enc *psRangeEnc, /* I/O compressor data structure */
const opus_int *pulses0 /* I data: nonnegative pulse amplitudes */
)
{
opus_int pulses1[ 8 ], pulses2[ 4 ], pulses3[ 2 ], pulses4[ 1 ];
/* this function operates on one shell code frame of 16 pulses */
silk_assert( SHELL_CODEC_FRAME_LENGTH == 16 );
/* tree representation per pulse-subframe */
combine_pulses( pulses1, pulses0, 8 );
combine_pulses( pulses2, pulses1, 4 );
combine_pulses( pulses3, pulses2, 2 );
combine_pulses( pulses4, pulses3, 1 );
encode_split( psRangeEnc, pulses3[ 0 ], pulses4[ 0 ], silk_shell_code_table3 );
encode_split( psRangeEnc, pulses2[ 0 ], pulses3[ 0 ], silk_shell_code_table2 );
encode_split( psRangeEnc, pulses1[ 0 ], pulses2[ 0 ], silk_shell_code_table1 );
encode_split( psRangeEnc, pulses0[ 0 ], pulses1[ 0 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses0[ 2 ], pulses1[ 1 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses1[ 2 ], pulses2[ 1 ], silk_shell_code_table1 );
encode_split( psRangeEnc, pulses0[ 4 ], pulses1[ 2 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses0[ 6 ], pulses1[ 3 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses2[ 2 ], pulses3[ 1 ], silk_shell_code_table2 );
encode_split( psRangeEnc, pulses1[ 4 ], pulses2[ 2 ], silk_shell_code_table1 );
encode_split( psRangeEnc, pulses0[ 8 ], pulses1[ 4 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses0[ 10 ], pulses1[ 5 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses1[ 6 ], pulses2[ 3 ], silk_shell_code_table1 );
encode_split( psRangeEnc, pulses0[ 12 ], pulses1[ 6 ], silk_shell_code_table0 );
encode_split( psRangeEnc, pulses0[ 14 ], pulses1[ 7 ], silk_shell_code_table0 );
}
/**********************************************************************
* Function to solve linear equation Ax = b, when A is a MxM
* symmetric square matrix - using LDL factorisation
**********************************************************************/
void silk_solve_LDL_FLP(
silk_float *A, /* I/O Symmetric square matrix, out: reg. */
const opus_int M, /* I Size of matrix */
const silk_float *b, /* I Pointer to b vector */
silk_float *x /* O Pointer to x solution vector */
)
{
opus_int i;
silk_float L[ MAX_MATRIX_SIZE ][ MAX_MATRIX_SIZE ];
silk_float T[ MAX_MATRIX_SIZE ];
silk_float Dinv[ MAX_MATRIX_SIZE ]; /* inverse diagonal elements of D*/
silk_assert(M <= MAX_MATRIX_SIZE);
/***************************************************
Factorize A by LDL such that A = L*D*(L^T),
where L is lower triangular with ones on diagonal
****************************************************/
silk_LDL_FLP(A, M, &L[ 0 ][ 0 ], Dinv);
/****************************************************
* substitute D*(L^T) = T. ie:
L*D*(L^T)*x = b => L*T = b <=> T = inv(L)*b
******************************************************/
silk_SolveWithLowerTriangularWdiagOnes_FLP(&L[ 0 ][ 0 ], M, b, T);
/****************************************************
D*(L^T)*x = T <=> (L^T)*x = inv(D)*T, because D is
diagonal just multiply with 1/d_i
****************************************************/
for(i = 0; i < M; i++) {
T[ i ] = T[ i ] * Dinv[ i ];
}
/****************************************************
x = inv(L') * inv(D) * T
*****************************************************/
silk_SolveWithUpperTriangularFromLowerWdiagOnes_FLP(&L[ 0 ][ 0 ], M, T, x);
}
