/* 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_Q16(
SKP_int32 *A_Q24, /* O: Prediction coefficients [order] Q24 */
const SKP_int32 *rc_Q16, /* I: Reflection coefficients [order] Q16 */
const SKP_int32 order /* I: Prediction order */
)
{
SKP_int k, n;
SKP_int32 Atmp[ SigProc_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_SMLAWW( A_Q24[ n ], Atmp[ k - n - 1 ], rc_Q16[ k ] );
}
A_Q24[ k ] = -SKP_LSHIFT( rc_Q16[ k ], 8 );
}
}
/* Solve L^t*x = b, where L is lower triangular with ones on the diagonal */
SKP_INLINE void SKP_Silk_LS_SolveLast_FIX(
const SKP_int32 *L_Q16, /* I Pointer to Lower Triangular Matrix */
const SKP_int M, /* I Dim of Matrix equation */
const SKP_int32 *b, /* I b Vector */
SKP_int32 *x_Q16 /* O x Vector */
)
{
SKP_int i, j;
const SKP_int32 *ptr32;
SKP_int32 tmp_32;
for( i = M - 1; i >= 0; i-- ) {
ptr32 = matrix_adr( L_Q16, 0, i, M );
tmp_32 = 0;
for( j = M - 1; j > i; j-- ) {
tmp_32 = SKP_SMLAWW( tmp_32, ptr32[ SKP_SMULBB( j, M ) ], x_Q16[ j ] );
}
x_Q16[ i ] = SKP_SUB32( b[ i ], tmp_32 );
}
}
/* Solve Lx = b, when L is lower triangular and has ones on the diagonal */
SKP_INLINE void SKP_Silk_LS_SolveFirst_FIX(
const SKP_int32 *L_Q16, /* I Pointer to Lower Triangular Matrix */
SKP_int M, /* I Dim of Matrix equation */
const SKP_int32 *b, /* I b Vector */
SKP_int32 *x_Q16 /* O x Vector */
)
{
SKP_int i, j;
const SKP_int32 *ptr32;
SKP_int32 tmp_32;
for( i = 0; i < M; i++ ) {
ptr32 = matrix_adr( L_Q16, i, 0, M );
tmp_32 = 0;
for( j = 0; j < i; j++ ) {
tmp_32 = SKP_SMLAWW( tmp_32, ptr32[ j ], x_Q16[ j ] );
}
x_Q16[ i ] = SKP_SUB32( b[ i ], tmp_32 );
}
}
SKP_INLINE void SKP_Silk_LDL_factorize_FIX(
SKP_int32 *A, /* I Pointer to Symetric Square Matrix */
SKP_int M, /* I Size of Matrix */
SKP_int32 *L_Q16, /* I/O Pointer to Square Upper triangular Matrix */
inv_D_t *inv_D /* I/O Pointer to vector holding inverted diagonal elements of D */
)
{
SKP_int i, j, k, status, loop_count;
const SKP_int32 *ptr1, *ptr2;
SKP_int32 diag_min_value, tmp_32, err;
SKP_int32 v_Q0[ MAX_MATRIX_SIZE ], D_Q0[ MAX_MATRIX_SIZE ];
SKP_int32 one_div_diag_Q36, one_div_diag_Q40, one_div_diag_Q48;
SKP_assert( M <= MAX_MATRIX_SIZE );
status = 1;
diag_min_value = SKP_max_32( SKP_SMMUL( SKP_ADD_SAT32( A[ 0 ], A[ SKP_SMULBB( M, M ) - 1 ] ), SKP_FIX_CONST( FIND_LTP_COND_FAC, 31 ) ), 1 << 9 );
for( loop_count = 0; loop_count < M && status == 1; loop_count++ ) {
status = 0;
for( j = 0; j < M; j++ ) {
ptr1 = matrix_adr( L_Q16, j, 0, M );
tmp_32 = 0;
for( i = 0; i < j; i++ ) {
v_Q0[ i ] = SKP_SMULWW( D_Q0[ i ], ptr1[ i ] ); /* Q0 */
tmp_32 = SKP_SMLAWW( tmp_32, v_Q0[ i ], ptr1[ i ] ); /* Q0 */
}
tmp_32 = SKP_SUB32( matrix_ptr( A, j, j, M ), tmp_32 );
if( tmp_32 < diag_min_value ) {
tmp_32 = SKP_SUB32( SKP_SMULBB( loop_count + 1, diag_min_value ), tmp_32 );
/* Matrix not positive semi-definite, or ill conditioned */
for( i = 0; i < M; i++ ) {
matrix_ptr( A, i, i, M ) = SKP_ADD32( matrix_ptr( A, i, i, M ), tmp_32 );
}
status = 1;
break;
}
D_Q0[ j ] = tmp_32; /* always < max(Correlation) */
/* two-step division */
one_div_diag_Q36 = SKP_INVERSE32_varQ( tmp_32, 36 ); /* Q36 */
one_div_diag_Q40 = SKP_LSHIFT( one_div_diag_Q36, 4 ); /* Q40 */
err = SKP_SUB32( 1 << 24, SKP_SMULWW( tmp_32, one_div_diag_Q40 ) ); /* Q24 */
one_div_diag_Q48 = SKP_SMULWW( err, one_div_diag_Q40 ); /* Q48 */
/* Save 1/Ds */
inv_D[ j ].Q36_part = one_div_diag_Q36;
inv_D[ j ].Q48_part = one_div_diag_Q48;
matrix_ptr( L_Q16, j, j, M ) = 65536; /* 1.0 in Q16 */
ptr1 = matrix_adr( A, j, 0, M );
ptr2 = matrix_adr( L_Q16, j + 1, 0, M );
for( i = j + 1; i < M; i++ ) {
tmp_32 = 0;
for( k = 0; k < j; k++ ) {
tmp_32 = SKP_SMLAWW( tmp_32, v_Q0[ k ], ptr2[ k ] ); /* Q0 */
}
tmp_32 = SKP_SUB32( ptr1[ i ], tmp_32 ); /* always < max(Correlation) */
/* tmp_32 / D_Q0[j] : Divide to Q16 */
matrix_ptr( L_Q16, i, j, M ) = SKP_ADD32( SKP_SMMUL( tmp_32, one_div_diag_Q48 ),
SKP_RSHIFT( SKP_SMULWW( tmp_32, one_div_diag_Q36 ), 4 ) );
/* go to next column */
ptr2 += M;
}
}
}
SKP_assert( status == 0 );
}
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 ) );
}
}
/* Compute reflection coefficients from input signal */
void SKP_Silk_burg_modified(
SKP_int32 *res_nrg, /* O residual energy */
SKP_int *res_nrg_Q, /* O residual energy Q value */
SKP_int32 A_Q16[], /* O prediction coefficients (length order) */
const SKP_int16 x[], /* I input signal, length: nb_subfr * ( D + subfr_length ) */
const SKP_int subfr_length, /* I input signal subframe length (including D preceeding samples) */
const SKP_int nb_subfr, /* I number of subframes stacked in x */
const SKP_int32 WhiteNoiseFrac_Q32, /* I fraction added to zero-lag autocorrelation */
const SKP_int D /* I order */
)
{
SKP_int k, n, s, lz, rshifts, rshifts_extra;
SKP_int32 C0, num, nrg, rc_Q31, Atmp_QA, Atmp1, tmp1, tmp2, x1, x2;
const SKP_int16 *x_ptr;
SKP_int32 C_first_row[ SKP_Silk_MAX_ORDER_LPC ];
SKP_int32 C_last_row[ SKP_Silk_MAX_ORDER_LPC ];
SKP_int32 Af_QA[ SKP_Silk_MAX_ORDER_LPC ];
SKP_int32 CAf[ SKP_Silk_MAX_ORDER_LPC + 1 ];
SKP_int32 CAb[ SKP_Silk_MAX_ORDER_LPC + 1 ];
SKP_assert( subfr_length * nb_subfr <= MAX_FRAME_SIZE );
SKP_assert( nb_subfr <= MAX_NB_SUBFR );
/* Compute autocorrelations, added over subframes */
SKP_Silk_sum_sqr_shift( &C0, &rshifts, x, nb_subfr * subfr_length );
if( rshifts > MAX_RSHIFTS ) {
C0 = SKP_LSHIFT32( C0, rshifts - MAX_RSHIFTS );
SKP_assert( C0 > 0 );
rshifts = MAX_RSHIFTS;
} else {
lz = SKP_Silk_CLZ32( C0 ) - 1;
rshifts_extra = N_BITS_HEAD_ROOM - lz;
if( rshifts_extra > 0 ) {
rshifts_extra = SKP_min( rshifts_extra, MAX_RSHIFTS - rshifts );
C0 = SKP_RSHIFT32( C0, rshifts_extra );
} else {
rshifts_extra = SKP_max( rshifts_extra, MIN_RSHIFTS - rshifts );
C0 = SKP_LSHIFT32( C0, -rshifts_extra );
}
rshifts += rshifts_extra;
}
SKP_memset( C_first_row, 0, SKP_Silk_MAX_ORDER_LPC * sizeof( SKP_int32 ) );
if( rshifts > 0 ) {
for( s = 0; s < nb_subfr; s++ ) {
x_ptr = x + s * subfr_length;
for( n = 1; n < D + 1; n++ ) {
C_first_row[ n - 1 ] += (SKP_int32)SKP_RSHIFT64(
SKP_Silk_inner_prod16_aligned_64( x_ptr, x_ptr + n, subfr_length - n ), rshifts );
}
}
} else {
for( s = 0; s < nb_subfr; s++ ) {
x_ptr = x + s * subfr_length;
for( n = 1; n < D + 1; n++ ) {
C_first_row[ n - 1 ] += SKP_LSHIFT32(
SKP_Silk_inner_prod_aligned( x_ptr, x_ptr + n, subfr_length - n ), -rshifts );
}
}
}
SKP_memcpy( C_last_row, C_first_row, SKP_Silk_MAX_ORDER_LPC * sizeof( SKP_int32 ) );
/* Initialize */
CAb[ 0 ] = CAf[ 0 ] = C0 + SKP_SMMUL( WhiteNoiseFrac_Q32, C0 ) + 1; // Q(-rshifts)
for( n = 0; n < D; n++ ) {
/* Update first row of correlation matrix (without first element) */
/* Update last row of correlation matrix (without last element, stored in reversed order) */
/* Update C * Af */
/* Update C * flipud(Af) (stored in reversed order) */
if( rshifts > -2 ) {
for( s = 0; s < nb_subfr; s++ ) {
x_ptr = x + s * subfr_length;
x1 = -SKP_LSHIFT32( (SKP_int32)x_ptr[ n ], 16 - rshifts ); // Q(16-rshifts)
x2 = -SKP_LSHIFT32( (SKP_int32)x_ptr[ subfr_length - n - 1 ], 16 - rshifts ); // Q(16-rshifts)
tmp1 = SKP_LSHIFT32( (SKP_int32)x_ptr[ n ], QA - 16 ); // Q(QA-16)
tmp2 = SKP_LSHIFT32( (SKP_int32)x_ptr[ subfr_length - n - 1 ], QA - 16 ); // Q(QA-16)
for( k = 0; k < n; k++ ) {
C_first_row[ k ] = SKP_SMLAWB( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); // Q( -rshifts )
C_last_row[ k ] = SKP_SMLAWB( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); // Q( -rshifts )
Atmp_QA = Af_QA[ k ];
tmp1 = SKP_SMLAWB( tmp1, Atmp_QA, x_ptr[ n - k - 1 ] ); // Q(QA-16)
tmp2 = SKP_SMLAWB( tmp2, Atmp_QA, x_ptr[ subfr_length - n + k ] ); // Q(QA-16)
}
tmp1 = SKP_LSHIFT32( -tmp1, 32 - QA - rshifts ); // Q(16-rshifts)
tmp2 = SKP_LSHIFT32( -tmp2, 32 - QA - rshifts ); // Q(16-rshifts)
for( k = 0; k <= n; k++ ) {
CAf[ k ] = SKP_SMLAWB( CAf[ k ], tmp1, x_ptr[ n - k ] ); // Q( -rshift )
CAb[ k ] = SKP_SMLAWB( CAb[ k ], tmp2, x_ptr[ subfr_length - n + k - 1 ] ); // Q( -rshift )
}
}
} else {
for( s = 0; s < nb_subfr; s++ ) {
x_ptr = x + s * subfr_length;
x1 = -SKP_LSHIFT32( (SKP_int32)x_ptr[ n ], -rshifts ); // Q( -rshifts )
x2 = -SKP_LSHIFT32( (SKP_int32)x_ptr[ subfr_length - n - 1 ], -rshifts ); // Q( -rshifts )
tmp1 = SKP_LSHIFT32( (SKP_int32)x_ptr[ n ], 17 ); // Q17
tmp2 = SKP_LSHIFT32( (SKP_int32)x_ptr[ subfr_length - n - 1 ], 17 ); // Q17
for( k = 0; k < n; k++ ) {
C_first_row[ k ] = SKP_MLA( C_first_row[ k ], x1, x_ptr[ n - k - 1 ] ); // Q( -rshifts )
C_last_row[ k ] = SKP_MLA( C_last_row[ k ], x2, x_ptr[ subfr_length - n + k ] ); // Q( -rshifts )
Atmp1 = SKP_RSHIFT_ROUND( Af_QA[ k ], QA - 17 ); // Q17
tmp1 = SKP_MLA( tmp1, x_ptr[ n - k - 1 ], Atmp1 ); // Q17
tmp2 = SKP_MLA( tmp2, x_ptr[ subfr_length - n + k ], Atmp1 ); // Q17
}
tmp1 = -tmp1; // Q17
tmp2 = -tmp2; // Q17
for( k = 0; k <= n; k++ ) {
CAf[ k ] = SKP_SMLAWW( CAf[ k ], tmp1,
SKP_LSHIFT32( (SKP_int32)x_ptr[ n - k ], -rshifts - 1 ) ); // Q( -rshift )
CAb[ k ] = SKP_SMLAWW( CAb[ k ], tmp2,
SKP_LSHIFT32( (SKP_int32)x_ptr[ subfr_length - n + k - 1 ], -rshifts - 1 ) );// Q( -rshift )
}
}
}
/* Calculate nominator and denominator for the next order reflection (parcor) coefficient */
tmp1 = C_first_row[ n ]; // Q( -rshifts )
tmp2 = C_last_row[ n ]; // Q( -rshifts )
num = 0; // Q( -rshifts )
nrg = SKP_ADD32( CAb[ 0 ], CAf[ 0 ] ); // Q( 1-rshifts )
for( k = 0; k < n; k++ ) {
Atmp_QA = Af_QA[ k ];
lz = SKP_Silk_CLZ32( SKP_abs( Atmp_QA ) ) - 1;
lz = SKP_min( 32 - QA, lz );
Atmp1 = SKP_LSHIFT32( Atmp_QA, lz ); // Q( QA + lz )
tmp1 = SKP_ADD_LSHIFT32( tmp1, SKP_SMMUL( C_last_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); // Q( -rshifts )
tmp2 = SKP_ADD_LSHIFT32( tmp2, SKP_SMMUL( C_first_row[ n - k - 1 ], Atmp1 ), 32 - QA - lz ); // Q( -rshifts )
num = SKP_ADD_LSHIFT32( num, SKP_SMMUL( CAb[ n - k ], Atmp1 ), 32 - QA - lz ); // Q( -rshifts )
nrg = SKP_ADD_LSHIFT32( nrg, SKP_SMMUL( SKP_ADD32( CAb[ k + 1 ], CAf[ k + 1 ] ),
Atmp1 ), 32 - QA - lz ); // Q( 1-rshifts )
}
CAf[ n + 1 ] = tmp1; // Q( -rshifts )
CAb[ n + 1 ] = tmp2; // Q( -rshifts )
num = SKP_ADD32( num, tmp2 ); // Q( -rshifts )
num = SKP_LSHIFT32( -num, 1 ); // Q( 1-rshifts )
/* Calculate the next order reflection (parcor) coefficient */
if( SKP_abs( num ) < nrg ) {
rc_Q31 = SKP_DIV32_varQ( num, nrg, 31 );
} else {
/* Negative energy or ratio too high; set remaining coefficients to zero and exit loop */
SKP_memset( &Af_QA[ n ], 0, ( D - n ) * sizeof( SKP_int32 ) );
SKP_assert( 0 );
break;
}
/* Update the AR coefficients */
for( k = 0; k < (n + 1) >> 1; k++ ) {
tmp1 = Af_QA[ k ]; // QA
tmp2 = Af_QA[ n - k - 1 ]; // QA
Af_QA[ k ] = SKP_ADD_LSHIFT32( tmp1, SKP_SMMUL( tmp2, rc_Q31 ), 1 ); // QA
Af_QA[ n - k - 1 ] = SKP_ADD_LSHIFT32( tmp2, SKP_SMMUL( tmp1, rc_Q31 ), 1 ); // QA
}
Af_QA[ n ] = SKP_RSHIFT32( rc_Q31, 31 - QA ); // QA
/* Update C * Af and C * Ab */
for( k = 0; k <= n + 1; k++ ) {
tmp1 = CAf[ k ]; // Q( -rshifts )
tmp2 = CAb[ n - k + 1 ]; // Q( -rshifts )
CAf[ k ] = SKP_ADD_LSHIFT32( tmp1, SKP_SMMUL( tmp2, rc_Q31 ), 1 ); // Q( -rshifts )
CAb[ n - k + 1 ] = SKP_ADD_LSHIFT32( tmp2, SKP_SMMUL( tmp1, rc_Q31 ), 1 ); // Q( -rshifts )
}
}
/* Return residual energy */
nrg = CAf[ 0 ]; // Q( -rshifts )
tmp1 = 1 << 16; // Q16
for( k = 0; k < D; k++ ) {
Atmp1 = SKP_RSHIFT_ROUND( Af_QA[ k ], QA - 16 ); // Q16
nrg = SKP_SMLAWW( nrg, CAf[ k + 1 ], Atmp1 ); // Q( -rshifts )
tmp1 = SKP_SMLAWW( tmp1, Atmp1, Atmp1 ); // Q16
A_Q16[ k ] = -Atmp1;
}
*res_nrg = SKP_SMLAWW( nrg, SKP_SMMUL( WhiteNoiseFrac_Q32, C0 ), -tmp1 ); // Q( -rshifts )
*res_nrg_Q = -rshifts;
}
/* Processing of gains */
void SKP_Silk_process_gains_FIX(
SKP_Silk_encoder_state_FIX *psEnc, /* I/O Encoder state_FIX */
SKP_Silk_encoder_control_FIX *psEncCtrl /* I/O Encoder control_FIX */
)
{
SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
SKP_int k;
SKP_int32 s_Q16, InvMaxSqrVal_Q16, gain, gain_squared, ResNrg, ResNrgPart;
/* Gain reduction when LTP coding gain is high */
if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
/*s = -0.5f * SKP_sigmoid( 0.25f * ( psEncCtrl->LTPredCodGain - 12.0f ) ); */
s_Q16 = -SKP_Silk_sigm_Q15( SKP_RSHIFT_ROUND( psEncCtrl->LTPredCodGain_Q7 - (12 << 7), 4 ) );
for( k = 0; k < NB_SUBFR; k++ ) {
psEncCtrl->Gains_Q16[ k ] = SKP_SMLAWB( psEncCtrl->Gains_Q16[ k ], psEncCtrl->Gains_Q16[ k ], s_Q16 );
}
}
/* Limit the quantized signal */
/* 69 = 21.0f + 16/0.33 */
InvMaxSqrVal_Q16 = SKP_DIV32_16( SKP_Silk_log2lin(
SKP_SMULWB( (69 << 7) - psEncCtrl->current_SNR_dB_Q7, SKP_FIX_CONST( 0.33, 16 )) ), psEnc->sCmn.subfr_length );
for( k = 0; k < 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 ) {
if( psEncCtrl->ResNrgQ[ k ] < 32 ) {
ResNrgPart = SKP_RSHIFT_ROUND( ResNrgPart, psEncCtrl->ResNrgQ[ k ] );
} else {
ResNrgPart = 0;
}
} else if( psEncCtrl->ResNrgQ[k] != 0 ) {
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 = SKP_Silk_SQRT_APPROX( gain_squared ); /* Q8 */
psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 8 ); /* Q16 */
} else {
gain = SKP_Silk_SQRT_APPROX( gain_squared ); /* Q0 */
psEncCtrl->Gains_Q16[ k ] = SKP_LSHIFT_SAT32( gain, 16 ); /* Q16 */
}
}
/* Noise shaping quantization */
SKP_Silk_gains_quant( psEncCtrl->sCmn.GainsIndices, psEncCtrl->Gains_Q16,
&psShapeSt->LastGainIndex, psEnc->sCmn.nFramesInPayloadBuf );
/* Set quantizer offset for voiced signals. Larger offset when LTP coding gain is low or tilt is high (ie low-pass) */
if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
if( psEncCtrl->LTPredCodGain_Q7 + SKP_RSHIFT( psEncCtrl->input_tilt_Q15, 8 ) > ( 1 << 7 ) ) {
psEncCtrl->sCmn.QuantOffsetType = 0;
} else {
psEncCtrl->sCmn.QuantOffsetType = 1;
}
}
/* Quantizer boundary adjustment */
if( psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED ) {
psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 )
- SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8 )
- SKP_SMULWB( SKP_FIX_CONST( 0.3, 12 ), psEncCtrl->input_quality_Q14 )
+ SKP_SMULBB( SKP_FIX_CONST( 0.2, 10 ), psEncCtrl->sCmn.QuantOffsetType )
- SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14 );
} else {
psEncCtrl->Lambda_Q10 = SKP_FIX_CONST( 1.3, 10 )
- SKP_SMULWB( SKP_FIX_CONST( 0.5, 18 ), psEnc->speech_activity_Q8 )
- SKP_SMULWB( SKP_FIX_CONST( 0.4, 12 ), psEncCtrl->input_quality_Q14 )
+ SKP_SMULBB( SKP_FIX_CONST( 0.4, 10 ), psEncCtrl->sCmn.QuantOffsetType )
- SKP_SMULWB( SKP_FIX_CONST( 0.1, 12 ), psEncCtrl->coding_quality_Q14 );
}
SKP_assert( psEncCtrl->Lambda_Q10 >= 0 );
SKP_assert( psEncCtrl->Lambda_Q10 < SKP_FIX_CONST( 2, 10 ) );
}
