/* Glues concealed frames with new good recieved frames */
void SKP_Silk_PLC_glue_frames(
SKP_Silk_decoder_state *psDec, /* I/O decoder state */
SKP_Silk_decoder_control *psDecCtrl, /* I/O Decoder control */
SKP_int16 signal[], /* I/O signal */
SKP_int length /* I length of residual */
)
{
SKP_int i, energy_shift;
SKP_int32 energy;
SKP_Silk_PLC_struct *psPLC;
psPLC = &psDec->sPLC;
if( psDec->lossCnt ) {
/* Calculate energy in concealed residual */
SKP_Silk_sum_sqr_shift( &psPLC->conc_energy, &psPLC->conc_energy_shift, signal, length );
psPLC->last_frame_lost = 1;
} else {
if( psDec->sPLC.last_frame_lost ) {
/* Calculate residual in decoded signal if last frame was lost */
SKP_Silk_sum_sqr_shift( &energy, &energy_shift, signal, length );
/* Normalize energies */
if( energy_shift > psPLC->conc_energy_shift ) {
psPLC->conc_energy = SKP_RSHIFT( psPLC->conc_energy, energy_shift - psPLC->conc_energy_shift );
} else if( energy_shift < psPLC->conc_energy_shift ) {
energy = SKP_RSHIFT( energy, psPLC->conc_energy_shift - energy_shift );
}
/* Fade in the energy difference */
if( energy > psPLC->conc_energy ) {
SKP_int32 frac_Q24, LZ;
SKP_int32 gain_Q12, slope_Q12;
LZ = SKP_Silk_CLZ32( psPLC->conc_energy );
LZ = LZ - 1;
psPLC->conc_energy = SKP_LSHIFT( psPLC->conc_energy, LZ );
energy = SKP_RSHIFT( energy, SKP_max_32( 24 - LZ, 0 ) );
frac_Q24 = SKP_DIV32( psPLC->conc_energy, SKP_max( energy, 1 ) );
gain_Q12 = SKP_Silk_SQRT_APPROX( frac_Q24 );
slope_Q12 = SKP_DIV32_16( ( 1 << 12 ) - gain_Q12, length );
for( i = 0; i < length; i++ ) {
signal[ i ] = SKP_RSHIFT( SKP_MUL( gain_Q12, signal[ i ] ), 12 );
gain_Q12 += slope_Q12;
gain_Q12 = SKP_min( gain_Q12, ( 1 << 12 ) );
}
}
}
psPLC->last_frame_lost = 0;
}
}
/* 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];
}
/* Determine length of bitstream */
SKP_int SKP_Silk_range_coder_get_length( /* O returns number of BITS in stream */
const SKP_Silk_range_coder_state *psRC, /* I compressed data structure */
SKP_int *nBytes /* O number of BYTES in stream */
)
{
SKP_int nBits;
/* Number of bits in stream */
nBits = SKP_LSHIFT( psRC->bufferIx, 3 ) + SKP_Silk_CLZ32( psRC->range_Q16 - 1 ) - 14;
*nBytes = SKP_RSHIFT( nBits + 7, 3 );
/* Return number of bits in bitstream */
return nBits;
}
/* Calculates correlation matrix X'*X */
void SKP_Silk_corrMatrix_FIX(
const SKP_int16 *x, /* I x vector [L + order - 1] used to form data matrix X */
const SKP_int L, /* I Length of vectors */
const SKP_int order, /* I Max lag for correlation */
const SKP_int head_room, /* I Desired headroom */
SKP_int32 *XX, /* O Pointer to X'*X correlation matrix [ order x order ]*/
SKP_int *rshifts /* I/O Right shifts of correlations */
)
{
SKP_int i, j, lag, rshifts_local, head_room_rshifts;
SKP_int32 energy;
const SKP_int16 *ptr1, *ptr2;
/* Calculate energy to find shift used to fit in 32 bits */
SKP_Silk_sum_sqr_shift( &energy, &rshifts_local, x, L + order - 1 );
/* Add shifts to get the desired head room */
head_room_rshifts = SKP_max( head_room - SKP_Silk_CLZ32( energy ), 0 );
energy = SKP_RSHIFT32( energy, head_room_rshifts );
rshifts_local += head_room_rshifts;
/* Calculate energy of first column (0) of X: X[:,0]'*X[:,0] */
/* Remove contribution of first order - 1 samples */
for( i = 0; i < order - 1; i++ ) {
energy -= SKP_RSHIFT32( SKP_SMULBB( x[ i ], x[ i ] ), rshifts_local );
}
if( rshifts_local < *rshifts ) {
/* Adjust energy */
energy = SKP_RSHIFT32( energy, *rshifts - rshifts_local );
rshifts_local = *rshifts;
}
/* Calculate energy of remaining columns of X: X[:,j]'*X[:,j] */
/* Fill out the diagonal of the correlation matrix */
matrix_ptr( XX, 0, 0, order ) = energy;
ptr1 = &x[ order - 1 ]; /* First sample of column 0 of X */
for( j = 1; j < order; j++ ) {
energy = SKP_SUB32( energy, SKP_RSHIFT32( SKP_SMULBB( ptr1[ L - j ], ptr1[ L - j ] ), rshifts_local ) );
energy = SKP_ADD32( energy, SKP_RSHIFT32( SKP_SMULBB( ptr1[ -j ], ptr1[ -j ] ), rshifts_local ) );
matrix_ptr( XX, j, j, order ) = energy;
}
ptr2 = &x[ order - 2 ]; /* First sample of column 1 of X */
/* Calculate the remaining elements of the correlation matrix */
if( rshifts_local > 0 ) {
/* Right shifting used */
for( lag = 1; lag < order; lag++ ) {
/* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
energy = 0;
for( i = 0; i < L; i++ ) {
energy += SKP_RSHIFT32( SKP_SMULBB( ptr1[ i ], ptr2[i] ), rshifts_local );
}
/* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
matrix_ptr( XX, lag, 0, order ) = energy;
matrix_ptr( XX, 0, lag, order ) = energy;
for( j = 1; j < ( order - lag ); j++ ) {
energy = SKP_SUB32( energy, SKP_RSHIFT32( SKP_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ), rshifts_local ) );
energy = SKP_ADD32( energy, SKP_RSHIFT32( SKP_SMULBB( ptr1[ -j ], ptr2[ -j ] ), rshifts_local ) );
matrix_ptr( XX, lag + j, j, order ) = energy;
matrix_ptr( XX, j, lag + j, order ) = energy;
}
ptr2--; /* Update pointer to first sample of next column (lag) in X */
}
} else {
for( lag = 1; lag < order; lag++ ) {
/* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
energy = SKP_Silk_inner_prod_aligned( ptr1, ptr2, L );
matrix_ptr( XX, lag, 0, order ) = energy;
matrix_ptr( XX, 0, lag, order ) = energy;
/* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
for( j = 1; j < ( order - lag ); j++ ) {
energy = SKP_SUB32( energy, SKP_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ) );
energy = SKP_SMLABB( energy, ptr1[ -j ], ptr2[ -j ] );
matrix_ptr( XX, lag + j, j, order ) = energy;
matrix_ptr( XX, j, lag + j, order ) = energy;
}
ptr2--;/* Update pointer to first sample of next column (lag) in X */
}
}
*rshifts = rshifts_local;
}
/* 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;
}
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 [ 2 * frame_length + la_shape ]*/
)
{
SKP_Silk_shape_state_FIX *psShapeSt = &psEnc->sShape;
SKP_int k, nSamples, lz, Qnrg, b_Q14, scale = 0, sz;
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[ SHAPE_LPC_ORDER_MAX + 1 ];
SKP_int32 refl_coef_Q16[ SHAPE_LPC_ORDER_MAX ];
SKP_int32 AR_Q24[ SHAPE_LPC_ORDER_MAX ];
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 - SKP_SMULBB( SHAPE_LPC_WIN_MS, psEnc->sCmn.fs_kHz ) + psEnc->sCmn.frame_length / NB_SUBFR;
/****************/
/* 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 ), 3277 );
/* Reduce SNR_dB if inband FEC used */
if( psEnc->speech_activity_Q8 > LBRR_SPEECH_ACTIVITY_THRES_Q8 ) {
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 - ( 18 << 7 ), 4 ) ), 1 );
/* Reduce coding SNR during low speech activity */
b_Q8 = ( 1 << 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( -BG_SNR_DECR_dB_Q7 >> ( 4 + 1 ), b_Q8 ), // Q11
SKP_SMULWB( ( 1 << 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, HARM_SNR_INCR_dB_Q7 << 1, 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( 6 << ( 7 + 2 ), -104856, psEncCtrl->current_SNR_dB_Q7 ), //-104856_Q18 = -0.4_Q0, Q9
( 1 << 14 ) - psEncCtrl->input_quality_Q14 ); // 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 - ( 5 << 7 ), 6554 ) ), 7 ); // 6554_Q16 = 0.1_Q0
/* Set quantization offset depending on sparseness measure */
if( psEncCtrl->sparseness_Q8 > SPARSENESS_THRESHOLD_QNT_OFFSET_Q8 ) {
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, SPARSE_SNR_INCR_dB_Q7 << 8, psEncCtrl->sparseness_Q8 - ( 1 << 7 ) );
}
/*******************************/
/* Control bandwidth expansion */
/*******************************/
delta_Q16 = SKP_SMULWB( ( 1 << 16 ) - SKP_SMULBB( 3, psEncCtrl->coding_quality_Q14 ), LOW_RATE_BANDWIDTH_EXPANSION_DELTA_Q16 );
BWExp1_Q16 = BANDWIDTH_EXPANSION_Q16 - delta_Q16;
BWExp2_Q16 = BANDWIDTH_EXPANSION_Q16 + delta_Q16;
if( psEnc->sCmn.fs_kHz == 24 ) {
/* Less bandwidth expansion for super wideband */
BWExp1_Q16 = ( 1 << 16 ) - SKP_SMULWB( SWB_BANDWIDTH_EXPANSION_REDUCTION_Q16, ( 1 << 16 ) - BWExp1_Q16 );
BWExp2_Q16 = ( 1 << 16 ) - SKP_SMULWB( SWB_BANDWIDTH_EXPANSION_REDUCTION_Q16, ( 1 << 16 ) - BWExp2_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 ) );
/********************************************/
/* Compute noise shaping AR coefs and gains */
/********************************************/
sz = ( SKP_int )SKP_SMULBB( SHAPE_LPC_WIN_MS, psEnc->sCmn.fs_kHz );
for( k = 0; k < NB_SUBFR; k++ ) {
/* Apply window */
SKP_Silk_apply_sine_window( x_windowed, x_ptr, 0, SHAPE_LPC_WIN_MS * psEnc->sCmn.fs_kHz );
/* Update pointer: next LPC analysis block */
x_ptr += psEnc->sCmn.frame_length / NB_SUBFR;
/* Calculate auto correlation */
SKP_Silk_autocorr( auto_corr, &scale, x_windowed, sz, 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 ), SHAPE_WHITE_NOISE_FRACTION_Q20 ), 1 ) );
/* Calculate the reflection coefficients using schur */
nrg = SKP_Silk_schur64( refl_coef_Q16, auto_corr, psEnc->sCmn.shapingLPCOrder );
/* Convert reflection coefficients to prediction coefficients */
SKP_Silk_k2a_Q16( AR_Q24, refl_coef_Q16, psEnc->sCmn.shapingLPCOrder );
/* Bandwidth expansion for synthesis filter shaping */
SKP_Silk_bwexpander_32( AR_Q24, psEnc->sCmn.shapingLPCOrder, BWExp2_Q16 );
/* Make sure to fit in Q13 SKP_int16 */
SKP_Silk_LPC_fit( &psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ], AR_Q24, 13, psEnc->sCmn.shapingLPCOrder );
/* Compute noise shaping filter coefficients */
SKP_memcpy(
&psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ],
&psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ],
psEnc->sCmn.shapingLPCOrder * sizeof( SKP_int16 ) );
/* Bandwidth expansion for analysis filter shaping */
SKP_assert( BWExp1_Q16 <= ( 1 << 16 ) ); // If ever breaking, use LPC_stabilize() in these cases to stay within range
SKP_Silk_bwexpander( &psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder, BWExp1_Q16 );
/* Increase residual energy */
nrg = SKP_SMLAWB( nrg, SKP_RSHIFT( auto_corr[ 0 ], 8 ), SHAPE_MIN_ENERGY_RATIO_Q24 );
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 );
/* Ratio of prediction gains, in energy domain */
SKP_Silk_LPC_inverse_pred_gain_Q13( &pre_nrg_Q30, &psEncCtrl->AR2_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder );
SKP_Silk_LPC_inverse_pred_gain_Q13( &nrg, &psEncCtrl->AR1_Q13[ k * SHAPE_LPC_ORDER_MAX ], psEnc->sCmn.shapingLPCOrder );
lz = SKP_min_32( SKP_Silk_CLZ32( pre_nrg_Q30 ) - 1, 19 );
pre_nrg_Q30 = SKP_DIV32( SKP_LSHIFT( pre_nrg_Q30, lz ), SKP_RSHIFT( nrg, 20 - lz ) + 1 ); // Q20
pre_nrg_Q30 = SKP_RSHIFT( SKP_LSHIFT_SAT32( pre_nrg_Q30, 9 ), 1 ); /* Q28 */
psEncCtrl->GainsPre_Q14[ k ] = ( SKP_int )SKP_Silk_SQRT_APPROX( pre_nrg_Q30 );
}
void SKP_Silk_find_pred_coefs_FIX(SKP_Silk_encoder_state_FIX * psEnc, /* I/O encoder state */
SKP_Silk_encoder_control_FIX * psEncCtrl, /* I/O encoder control */
const int16_t res_pitch[] /* I Residual from pitch analysis */
)
{
int i;
int32_t WLTP[NB_SUBFR * LTP_ORDER * LTP_ORDER];
int32_t invGains_Q16[NB_SUBFR], local_gains_Qx[NB_SUBFR],
Wght_Q15[NB_SUBFR];
int NLSF_Q15[MAX_LPC_ORDER];
const int16_t *x_ptr;
int16_t *x_pre_ptr,
LPC_in_pre[NB_SUBFR * MAX_LPC_ORDER + MAX_FRAME_LENGTH];
int32_t tmp, min_gain_Q16;
#if !VARQ
int LZ;
#endif
int LTP_corrs_rshift[NB_SUBFR];
/* weighting for weighted least squares */
min_gain_Q16 = int32_t_MAX >> 6;
for (i = 0; i < NB_SUBFR; i++) {
min_gain_Q16 = SKP_min(min_gain_Q16, psEncCtrl->Gains_Q16[i]);
}
#if !VARQ
LZ = SKP_Silk_CLZ32(min_gain_Q16) - 1;
LZ = SKP_LIMIT(LZ, 0, 16);
min_gain_Q16 = SKP_RSHIFT(min_gain_Q16, 2); /* Ensure that maximum invGains_Q16 is within range of a 16 bit int */
#endif
for (i = 0; i < NB_SUBFR; i++) {
/* Divide to Q16 */
assert(psEncCtrl->Gains_Q16[i] > 0);
#if VARQ
/* Invert and normalize gains, and ensure that maximum invGains_Q16 is within range of a 16 bit int */
invGains_Q16[i] =
SKP_DIV32_varQ(min_gain_Q16, psEncCtrl->Gains_Q16[i],
16 - 2);
#else
invGains_Q16[i] =
SKP_DIV32(SKP_LSHIFT(min_gain_Q16, LZ),
SKP_RSHIFT(psEncCtrl->Gains_Q16[i], 16 - LZ));
#endif
/* Ensure Wght_Q15 a minimum value 1 */
invGains_Q16[i] = SKP_max(invGains_Q16[i], 363);
/* Square the inverted gains */
assert(invGains_Q16[i] == SKP_SAT16(invGains_Q16[i]));
tmp = SKP_SMULWB(invGains_Q16[i], invGains_Q16[i]);
Wght_Q15[i] = SKP_RSHIFT(tmp, 1);
/* Invert the inverted and normalized gains */
local_gains_Qx[i] =
SKP_DIV32((1 << (16 + Qx)), invGains_Q16[i]);
}
if (psEncCtrl->sCmn.sigtype == SIG_TYPE_VOICED) {
/**********/
/* VOICED */
/**********/
assert(psEnc->sCmn.frame_length -
psEnc->sCmn.predictLPCOrder >=
psEncCtrl->sCmn.pitchL[0] + LTP_ORDER / 2);
/* LTP analysis */
SKP_Silk_find_LTP_FIX(psEncCtrl->LTPCoef_Q14, WLTP,
&psEncCtrl->LTPredCodGain_Q7, res_pitch,
res_pitch +
SKP_RSHIFT(psEnc->sCmn.frame_length, 1),
psEncCtrl->sCmn.pitchL, Wght_Q15,
psEnc->sCmn.subfr_length,
psEnc->sCmn.frame_length,
LTP_corrs_rshift);
/* Quantize LTP gain parameters */
SKP_Silk_quant_LTP_gains_FIX(psEncCtrl->LTPCoef_Q14,
psEncCtrl->sCmn.LTPIndex,
&psEncCtrl->sCmn.PERIndex, WLTP,
psEnc->mu_LTP_Q8,
psEnc->sCmn.LTPQuantLowComplexity);
/* Control LTP scaling */
SKP_Silk_LTP_scale_ctrl_FIX(psEnc, psEncCtrl);
/* Create LTP residual */
SKP_Silk_LTP_analysis_filter_FIX(LPC_in_pre,
psEnc->x_buf +
psEnc->sCmn.frame_length -
psEnc->sCmn.predictLPCOrder,
psEncCtrl->LTPCoef_Q14,
psEncCtrl->sCmn.pitchL,
invGains_Q16, 16,
psEnc->sCmn.subfr_length,
psEnc->sCmn.predictLPCOrder);
} else {
/************/
/* UNVOICED */
/************/
/* Create signal with prepended subframes, scaled by inverse gains */
x_ptr =
psEnc->x_buf + psEnc->sCmn.frame_length -
psEnc->sCmn.predictLPCOrder;
x_pre_ptr = LPC_in_pre;
for (i = 0; i < NB_SUBFR; i++) {
SKP_Silk_scale_copy_vector16(x_pre_ptr, x_ptr,
invGains_Q16[i],
psEnc->sCmn.subfr_length +
psEnc->sCmn.
predictLPCOrder);
x_pre_ptr +=
psEnc->sCmn.subfr_length +
psEnc->sCmn.predictLPCOrder;
x_ptr += psEnc->sCmn.subfr_length;
}
SKP_memset(psEncCtrl->LTPCoef_Q14, 0,
NB_SUBFR * LTP_ORDER * sizeof(int16_t));
psEncCtrl->LTPredCodGain_Q7 = 0;
}
/* LPC_in_pre contains the LTP-filtered input for voiced, and the unfiltered input for unvoiced */
TIC(FIND_LPC)
SKP_Silk_find_LPC_FIX(NLSF_Q15, &psEncCtrl->sCmn.NLSFInterpCoef_Q2,
psEnc->sPred.prev_NLSFq_Q15,
psEnc->sCmn.useInterpolatedNLSFs * (1 -
psEnc->
sCmn.
first_frame_after_reset),
psEnc->sCmn.predictLPCOrder, LPC_in_pre,
psEnc->sCmn.subfr_length +
psEnc->sCmn.predictLPCOrder);
TOC(FIND_LPC)
/* Quantize LSFs */
TIC(PROCESS_LSFS)
SKP_Silk_process_NLSFs_FIX(psEnc, psEncCtrl, NLSF_Q15);
TOC(PROCESS_LSFS)
/* Calculate residual energy using quantized LPC coefficients */
SKP_Silk_residual_energy_FIX(psEncCtrl->ResNrg, psEncCtrl->ResNrgQ,
LPC_in_pre, (const int16_t(*)[])psEncCtrl->PredCoef_Q12,
local_gains_Qx, Qx,
psEnc->sCmn.subfr_length,
psEnc->sCmn.predictLPCOrder);
/* Copy to prediction struct for use in next frame for fluctuation reduction */
SKP_memcpy(psEnc->sPred.prev_NLSFq_Q15, NLSF_Q15,
psEnc->sCmn.predictLPCOrder * sizeof(int));
}
