void SKP_Silk_VAD_GetNoiseLevels(
const SKP_int32 pX[ VAD_N_BANDS ], /* I subband energies */
SKP_Silk_VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */
)
{
SKP_int k;
SKP_int32 nl, nrg, inv_nrg;
SKP_int coef, min_coef;
/* Initially faster smoothing */
if( psSilk_VAD->counter < 1000 ) { /* 1000 = 20 sec */
min_coef = SKP_DIV32_16( SKP_int16_MAX, SKP_RSHIFT( psSilk_VAD->counter, 4 ) + 1 );
} else {
min_coef = 0;
}
for( k = 0; k < VAD_N_BANDS; k++ ) {
/* Get old noise level estimate for current band */
nl = psSilk_VAD->NL[ k ];
SKP_assert( nl >= 0 );
/* Add bias */
nrg = SKP_ADD_POS_SAT32( pX[ k ], psSilk_VAD->NoiseLevelBias[ k ] );
SKP_assert( nrg > 0 );
/* Invert energies */
inv_nrg = SKP_DIV32( SKP_int32_MAX, nrg );
SKP_assert( inv_nrg >= 0 );
/* Less update when subband energy is high */
if( nrg > SKP_LSHIFT( nl, 3 ) ) {
coef = VAD_NOISE_LEVEL_SMOOTH_COEF_Q16 >> 3;
} else if( nrg < nl ) {
SKP_int SKP_Silk_VAD_Init( /* O Return value, 0 if success */
SKP_Silk_VAD_state *psSilk_VAD /* I/O Pointer to Silk VAD state */
)
{
SKP_int b, ret = 0;
/* reset state memory */
SKP_memset( psSilk_VAD, 0, sizeof( SKP_Silk_VAD_state ) );
/* init noise levels */
/* Initialize array with approx pink noise levels (psd proportional to inverse of frequency) */
for( b = 0; b < VAD_N_BANDS; b++ ) {
psSilk_VAD->NoiseLevelBias[ b ] = SKP_max_32( SKP_DIV32_16( VAD_NOISE_LEVELS_BIAS, b + 1 ), 1 );
}
/* Initialize state */
for( b = 0; b < VAD_N_BANDS; b++ ) {
psSilk_VAD->NL[ b ] = SKP_MUL( 100, psSilk_VAD->NoiseLevelBias[ b ] );
psSilk_VAD->inv_NL[ b ] = SKP_DIV32( SKP_int32_MAX, psSilk_VAD->NL[ b ] );
}
psSilk_VAD->counter = 15;
/* init smoothed energy-to-noise ratio*/
for( b = 0; b < VAD_N_BANDS; b++ ) {
psSilk_VAD->NrgRatioSmth_Q8[ b ] = 100 * 256; /* 100 * 256 --> 20 dB SNR */
}
return( ret );
}
/* 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;
}
}
/* Control SNR of redidual quantizer */
SKP_int silk_control_SNR(
silk_encoder_state *psEncC, /* I/O Pointer to Silk encoder state */
SKP_int32 TargetRate_bps /* I Target max bitrate (bps) */
)
{
SKP_int k, ret = SILK_NO_ERROR;
SKP_int32 frac_Q6;
const SKP_int32 *rateTable;
/* Set bitrate/coding quality */
TargetRate_bps = SKP_LIMIT( TargetRate_bps, MIN_TARGET_RATE_BPS, MAX_TARGET_RATE_BPS );
if( TargetRate_bps != psEncC->TargetRate_bps ) {
psEncC->TargetRate_bps = TargetRate_bps;
/* If new TargetRate_bps, translate to SNR_dB value */
if( psEncC->fs_kHz == 8 ) {
rateTable = silk_TargetRate_table_NB;
} else if( psEncC->fs_kHz == 12 ) {
rateTable = silk_TargetRate_table_MB;
} else {
rateTable = silk_TargetRate_table_WB;
}
/* Reduce bitrate for 10 ms modes in these calculations */
if( psEncC->nb_subfr == 2 ) {
TargetRate_bps -= REDUCE_BITRATE_10_MS_BPS;
}
/* Find bitrate interval in table and interpolate */
for( k = 1; k < TARGET_RATE_TAB_SZ; k++ ) {
if( TargetRate_bps <= rateTable[ k ] ) {
frac_Q6 = SKP_DIV32( SKP_LSHIFT( TargetRate_bps - rateTable[ k - 1 ], 6 ),
rateTable[ k ] - rateTable[ k - 1 ] );
psEncC->SNR_dB_Q7 = SKP_LSHIFT( silk_SNR_table_Q1[ k - 1 ], 6 ) + SKP_MUL( frac_Q6, silk_SNR_table_Q1[ k ] - silk_SNR_table_Q1[ k - 1 ] );
break;
}
}
}
return ret;
}
SKP_int SKP_Silk_VAD_GetSA_Q8( /* O Return value, 0 if success */
SKP_Silk_encoder_state *psEncC, /* I/O Encoder state */
const SKP_int16 pIn[] /* I PCM input */
)
{
SKP_int SA_Q15, pSNR_dB_Q7, input_tilt;
SKP_int decimated_framelength, dec_subframe_length, dec_subframe_offset, SNR_Q7, i, b, s;
SKP_int32 sumSquared, smooth_coef_Q16;
SKP_int16 HPstateTmp;
SKP_int16 X[ VAD_N_BANDS ][ MAX_FRAME_LENGTH / 2 ];
SKP_int32 Xnrg[ VAD_N_BANDS ];
SKP_int32 NrgToNoiseRatio_Q8[ VAD_N_BANDS ];
SKP_int32 speech_nrg, x_tmp;
SKP_int ret = 0;
SKP_Silk_VAD_state *psSilk_VAD = &psEncC->sVAD;
/* Safety checks */
SKP_assert( VAD_N_BANDS == 4 );
SKP_assert( MAX_FRAME_LENGTH >= psEncC->frame_length );
SKP_assert( psEncC->frame_length <= 512 );
SKP_assert( psEncC->frame_length == 8 * SKP_RSHIFT( psEncC->frame_length, 3 ) );
/***********************/
/* Filter and Decimate */
/***********************/
/* 0-8 kHz to 0-4 kHz and 4-8 kHz */
SKP_Silk_ana_filt_bank_1( pIn, &psSilk_VAD->AnaState[ 0 ], &X[ 0 ][ 0 ], &X[ 3 ][ 0 ], psEncC->frame_length );
/* 0-4 kHz to 0-2 kHz and 2-4 kHz */
SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState1[ 0 ], &X[ 0 ][ 0 ], &X[ 2 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 1 ) );
/* 0-2 kHz to 0-1 kHz and 1-2 kHz */
SKP_Silk_ana_filt_bank_1( &X[ 0 ][ 0 ], &psSilk_VAD->AnaState2[ 0 ], &X[ 0 ][ 0 ], &X[ 1 ][ 0 ], SKP_RSHIFT( psEncC->frame_length, 2 ) );
/*********************************************/
/* HP filter on lowest band (differentiator) */
/*********************************************/
decimated_framelength = SKP_RSHIFT( psEncC->frame_length, 3 );
X[ 0 ][ decimated_framelength - 1 ] = SKP_RSHIFT( X[ 0 ][ decimated_framelength - 1 ], 1 );
HPstateTmp = X[ 0 ][ decimated_framelength - 1 ];
for( i = decimated_framelength - 1; i > 0; i-- ) {
X[ 0 ][ i - 1 ] = SKP_RSHIFT( X[ 0 ][ i - 1 ], 1 );
X[ 0 ][ i ] -= X[ 0 ][ i - 1 ];
}
X[ 0 ][ 0 ] -= psSilk_VAD->HPstate;
psSilk_VAD->HPstate = HPstateTmp;
/*************************************/
/* Calculate the energy in each band */
/*************************************/
for( b = 0; b < VAD_N_BANDS; b++ ) {
/* Find the decimated framelength in the non-uniformly divided bands */
decimated_framelength = SKP_RSHIFT( psEncC->frame_length, SKP_min_int( VAD_N_BANDS - b, VAD_N_BANDS - 1 ) );
/* Split length into subframe lengths */
dec_subframe_length = SKP_RSHIFT( decimated_framelength, VAD_INTERNAL_SUBFRAMES_LOG2 );
dec_subframe_offset = 0;
/* Compute energy per sub-frame */
/* initialize with summed energy of last subframe */
Xnrg[ b ] = psSilk_VAD->XnrgSubfr[ b ];
for( s = 0; s < VAD_INTERNAL_SUBFRAMES; s++ ) {
sumSquared = 0;
for( i = 0; i < dec_subframe_length; i++ ) {
/* The energy will be less than dec_subframe_length * ( SKP_int16_MIN / 8 ) ^ 2. */
/* Therefore we can accumulate with no risk of overflow (unless dec_subframe_length > 128) */
x_tmp = SKP_RSHIFT( X[ b ][ i + dec_subframe_offset ], 3 );
sumSquared = SKP_SMLABB( sumSquared, x_tmp, x_tmp );
/* Safety check */
SKP_assert( sumSquared >= 0 );
}
/* Add/saturate summed energy of current subframe */
if( s < VAD_INTERNAL_SUBFRAMES - 1 ) {
Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], sumSquared );
} else {
/* Look-ahead subframe */
Xnrg[ b ] = SKP_ADD_POS_SAT32( Xnrg[ b ], SKP_RSHIFT( sumSquared, 1 ) );
}
dec_subframe_offset += dec_subframe_length;
}
psSilk_VAD->XnrgSubfr[ b ] = sumSquared;
}
/********************/
/* Noise estimation */
/********************/
SKP_Silk_VAD_GetNoiseLevels( &Xnrg[ 0 ], psSilk_VAD );
/***********************************************/
/* Signal-plus-noise to noise ratio estimation */
/***********************************************/
sumSquared = 0;
input_tilt = 0;
for( b = 0; b < VAD_N_BANDS; b++ ) {
speech_nrg = Xnrg[ b ] - psSilk_VAD->NL[ b ];
if( speech_nrg > 0 ) {
/* Divide, with sufficient resolution */
if( ( Xnrg[ b ] & 0xFF800000 ) == 0 ) {
NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( SKP_LSHIFT( Xnrg[ b ], 8 ), psSilk_VAD->NL[ b ] + 1 );
} else {
NrgToNoiseRatio_Q8[ b ] = SKP_DIV32( Xnrg[ b ], SKP_RSHIFT( psSilk_VAD->NL[ b ], 8 ) + 1 );
}
/* Convert to log domain */
SNR_Q7 = SKP_Silk_lin2log( NrgToNoiseRatio_Q8[ b ] ) - 8 * 128;
/* Sum-of-squares */
sumSquared = SKP_SMLABB( sumSquared, SNR_Q7, SNR_Q7 ); /* Q14 */
/* Tilt measure */
if( speech_nrg < ( 1 << 20 ) ) {
/* Scale down SNR value for small subband speech energies */
SNR_Q7 = SKP_SMULWB( SKP_LSHIFT( SKP_Silk_SQRT_APPROX( speech_nrg ), 6 ), SNR_Q7 );
}
input_tilt = SKP_SMLAWB( input_tilt, tiltWeights[ b ], SNR_Q7 );
} else {
NrgToNoiseRatio_Q8[ b ] = 256;
}
}
/* Mean-of-squares */
sumSquared = SKP_DIV32_16( sumSquared, VAD_N_BANDS ); /* Q14 */
/* Root-mean-square approximation, scale to dBs, and write to output pointer */
pSNR_dB_Q7 = ( SKP_int16 )( 3 * SKP_Silk_SQRT_APPROX( sumSquared ) ); /* Q7 */
/*********************************/
/* Speech Probability Estimation */
/*********************************/
SA_Q15 = SKP_Silk_sigm_Q15( SKP_SMULWB( VAD_SNR_FACTOR_Q16, pSNR_dB_Q7 ) - VAD_NEGATIVE_OFFSET_Q5 );
/**************************/
/* Frequency Tilt Measure */
/**************************/
psEncC->input_tilt_Q15 = SKP_LSHIFT( SKP_Silk_sigm_Q15( input_tilt ) - 16384, 1 );
/**************************************************/
/* Scale the sigmoid output based on power levels */
/**************************************************/
speech_nrg = 0;
for( b = 0; b < VAD_N_BANDS; b++ ) {
/* Accumulate signal-without-noise energies, higher frequency bands have more weight */
speech_nrg += ( b + 1 ) * SKP_RSHIFT( Xnrg[ b ] - psSilk_VAD->NL[ b ], 4 );
}
/* Power scaling */
if( speech_nrg <= 0 ) {
SA_Q15 = SKP_RSHIFT( SA_Q15, 1 );
} else if( speech_nrg < 32768 ) {
if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 16 );
} else {
speech_nrg = SKP_LSHIFT_SAT32( speech_nrg, 15 );
}
/* square-root */
speech_nrg = SKP_Silk_SQRT_APPROX( speech_nrg );
SA_Q15 = SKP_SMULWB( 32768 + speech_nrg, SA_Q15 );
}
/* Copy the resulting speech activity in Q8 */
psEncC->speech_activity_Q8 = SKP_min_int( SKP_RSHIFT( SA_Q15, 7 ), SKP_uint8_MAX );
/***********************************/
/* Energy Level and SNR estimation */
/***********************************/
/* Smoothing coefficient */
smooth_coef_Q16 = SKP_SMULWB( VAD_SNR_SMOOTH_COEF_Q18, SKP_SMULWB( SA_Q15, SA_Q15 ) );
if( psEncC->frame_length == 10 * psEncC->fs_kHz ) {
smooth_coef_Q16 >>= 1;
}
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 SKP_int16 res_pitch[], /* I Residual from pitch analysis */
const SKP_int16 x[] /* I Speech signal */
)
{
SKP_int i;
SKP_int32 WLTP[ MAX_NB_SUBFR * LTP_ORDER * LTP_ORDER ];
SKP_int32 invGains_Q16[ MAX_NB_SUBFR ], local_gains[ MAX_NB_SUBFR ], Wght_Q15[ MAX_NB_SUBFR ];
SKP_int16 NLSF_Q15[ MAX_LPC_ORDER ];
const SKP_int16 *x_ptr;
SKP_int16 *x_pre_ptr, LPC_in_pre[ MAX_NB_SUBFR * MAX_LPC_ORDER + MAX_FRAME_LENGTH ];
SKP_int32 tmp, min_gain_Q16;
SKP_int LTP_corrs_rshift[ MAX_NB_SUBFR ];
/* weighting for weighted least squares */
min_gain_Q16 = SKP_int32_MAX >> 6;
for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
min_gain_Q16 = SKP_min( min_gain_Q16, psEncCtrl->Gains_Q16[ i ] );
}
for( i = 0; i < psEnc->sCmn.nb_subfr; i++ ) {
/* Divide to Q16 */
SKP_assert( psEncCtrl->Gains_Q16[ i ] > 0 );
/* 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 );
/* Ensure Wght_Q15 a minimum value 1 */
invGains_Q16[ i ] = SKP_max( invGains_Q16[ i ], 363 );
/* Square the inverted gains */
SKP_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[ i ] = SKP_DIV32( ( 1 << 16 ), invGains_Q16[ i ] );
}
if( psEnc->sCmn.indices.signalType == TYPE_VOICED ) {
/**********/
/* VOICED */
/**********/
SKP_assert( psEnc->sCmn.ltp_mem_length - psEnc->sCmn.predictLPCOrder >= psEncCtrl->pitchL[ 0 ] + LTP_ORDER / 2 );
/* LTP analysis */
SKP_Silk_find_LTP_FIX( psEncCtrl->LTPCoef_Q14, WLTP, &psEncCtrl->LTPredCodGain_Q7,
res_pitch, psEncCtrl->pitchL, Wght_Q15, psEnc->sCmn.subfr_length,
psEnc->sCmn.nb_subfr, psEnc->sCmn.ltp_mem_length, LTP_corrs_rshift );
/* Quantize LTP gain parameters */
SKP_Silk_quant_LTP_gains( psEncCtrl->LTPCoef_Q14, psEnc->sCmn.indices.LTPIndex, &psEnc->sCmn.indices.PERIndex,
WLTP, psEnc->sCmn.mu_LTP_Q9, psEnc->sCmn.LTPQuantLowComplexity, psEnc->sCmn.nb_subfr);
/* 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.ltp_mem_length - psEnc->sCmn.predictLPCOrder,
psEncCtrl->LTPCoef_Q14, psEncCtrl->pitchL, invGains_Q16, psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );
} else {
/************/
/* UNVOICED */
/************/
/* Create signal with prepended subframes, scaled by inverse gains */
x_ptr = x - psEnc->sCmn.predictLPCOrder;
x_pre_ptr = LPC_in_pre;
for( i = 0; i < psEnc->sCmn.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, psEnc->sCmn.nb_subfr * LTP_ORDER * sizeof( SKP_int16 ) );
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, &psEnc->sCmn.indices.NLSFInterpCoef_Q2, psEnc->sCmn.prev_NLSFq_Q15,
psEnc->sCmn.useInterpolatedNLSFs, psEnc->sCmn.first_frame_after_reset, psEnc->sCmn.predictLPCOrder,
LPC_in_pre, psEnc->sCmn.subfr_length + psEnc->sCmn.predictLPCOrder, psEnc->sCmn.nb_subfr );
TOC(FIND_LPC)
/* Quantize LSFs */
TIC(PROCESS_LSFS)
SKP_Silk_process_NLSFs( &psEnc->sCmn, psEncCtrl->PredCoef_Q12, NLSF_Q15, psEnc->sCmn.prev_NLSFq_Q15 );
TOC(PROCESS_LSFS)
/* Calculate residual energy using quantized LPC coefficients */
SKP_Silk_residual_energy_FIX( psEncCtrl->ResNrg, psEncCtrl->ResNrgQ, LPC_in_pre, psEncCtrl->PredCoef_Q12, local_gains,
psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr, psEnc->sCmn.predictLPCOrder );
/* Copy to prediction struct for use in next frame for fluctuation reduction */
SKP_memcpy( psEnc->sCmn.prev_NLSFq_Q15, NLSF_Q15, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
}
void SKP_Silk_PLC_update(
SKP_Silk_decoder_state *psDec, /* (I/O) Decoder state */
SKP_Silk_decoder_control *psDecCtrl, /* (I/O) Decoder control */
SKP_int16 signal[],
SKP_int length
)
{
SKP_int32 LTP_Gain_Q14, temp_LTP_Gain_Q14;
SKP_int i, j;
SKP_Silk_PLC_struct *psPLC;
psPLC = &psDec->sPLC;
/* Update parameters used in case of packet loss */
psDec->prev_sigtype = psDecCtrl->sigtype;
LTP_Gain_Q14 = 0;
if( psDecCtrl->sigtype == SIG_TYPE_VOICED ) {
/* Find the parameters for the last subframe which contains a pitch pulse */
for( j = 0; j * psDec->subfr_length < psDecCtrl->pitchL[ NB_SUBFR - 1 ]; j++ ) {
temp_LTP_Gain_Q14 = 0;
for( i = 0; i < LTP_ORDER; i++ ) {
temp_LTP_Gain_Q14 += psDecCtrl->LTPCoef_Q14[ ( NB_SUBFR - 1 - j ) * LTP_ORDER + i ];
}
if( temp_LTP_Gain_Q14 > LTP_Gain_Q14 ) {
LTP_Gain_Q14 = temp_LTP_Gain_Q14;
SKP_memcpy( psPLC->LTPCoef_Q14,
&psDecCtrl->LTPCoef_Q14[ SKP_SMULBB( NB_SUBFR - 1 - j, LTP_ORDER ) ],
LTP_ORDER * sizeof( SKP_int16 ) );
psPLC->pitchL_Q8 = SKP_LSHIFT( psDecCtrl->pitchL[ NB_SUBFR - 1 - j ], 8 );
}
}
#if USE_SINGLE_TAP
SKP_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( SKP_int16 ) );
psPLC->LTPCoef_Q14[ LTP_ORDER / 2 ] = LTP_Gain_Q14;
#endif
/* Limit LT coefs */
if( LTP_Gain_Q14 < V_PITCH_GAIN_START_MIN_Q14 ) {
SKP_int scale_Q10;
SKP_int32 tmp;
tmp = SKP_LSHIFT( V_PITCH_GAIN_START_MIN_Q14, 10 );
scale_Q10 = SKP_DIV32( tmp, SKP_max( LTP_Gain_Q14, 1 ) );
for( i = 0; i < LTP_ORDER; i++ ) {
psPLC->LTPCoef_Q14[ i ] = SKP_RSHIFT( SKP_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q10 ), 10 );
}
} else if( LTP_Gain_Q14 > V_PITCH_GAIN_START_MAX_Q14 ) {
SKP_int scale_Q14;
SKP_int32 tmp;
tmp = SKP_LSHIFT( V_PITCH_GAIN_START_MAX_Q14, 14 );
scale_Q14 = SKP_DIV32( tmp, SKP_max( LTP_Gain_Q14, 1 ) );
for( i = 0; i < LTP_ORDER; i++ ) {
psPLC->LTPCoef_Q14[ i ] = SKP_RSHIFT( SKP_SMULBB( psPLC->LTPCoef_Q14[ i ], scale_Q14 ), 14 );
}
}
} else {
psPLC->pitchL_Q8 = SKP_LSHIFT( SKP_SMULBB( psDec->fs_kHz, 18 ), 8 );
SKP_memset( psPLC->LTPCoef_Q14, 0, LTP_ORDER * sizeof( SKP_int16 ));
}
/* Save LPC coeficients */
SKP_memcpy( psPLC->prevLPC_Q12, psDecCtrl->PredCoef_Q12[ 1 ], psDec->LPC_order * sizeof( SKP_int16 ) );
psPLC->prevLTP_scale_Q14 = psDecCtrl->LTP_scale_Q14;
/* Save Gains */
SKP_memcpy( psPLC->prevGain_Q16, psDecCtrl->Gains_Q16, NB_SUBFR * sizeof( SKP_int32 ) );
}
int SKP_Silk_encode_frame_FIX(SKP_Silk_encoder_state_FIX * psEnc, /* I/O Pointer to Silk FIX encoder state */
uint8_t * pCode, /* O Pointer to payload */
int16_t * pnBytesOut, /* I/O Pointer to number of payload bytes */
/* input: max length; output: used */
const int16_t * pIn /* I Pointer to input speech frame */
) {
SKP_Silk_encoder_control_FIX sEncCtrl;
int i, nBytes, ret = 0;
int16_t *x_frame, *res_pitch_frame;
int16_t xfw[MAX_FRAME_LENGTH];
int16_t pIn_HP[MAX_FRAME_LENGTH];
int16_t res_pitch[2 * MAX_FRAME_LENGTH + LA_PITCH_MAX];
int LBRR_idx, frame_terminator, SNR_dB_Q7;
const uint16_t *FrameTermination_CDF;
/* Low bitrate redundancy parameters */
uint8_t LBRRpayload[MAX_ARITHM_BYTES];
int16_t nBytesLBRR;
//int32_t Seed[ MAX_LAYERS ];
sEncCtrl.sCmn.Seed = psEnc->sCmn.frameCounter++ & 3;
/**************************************************************/
/* Setup Input Pointers, and insert frame in input buffer */
/*************************************************************/
x_frame = psEnc->x_buf + psEnc->sCmn.frame_length; /* start of frame to encode */
res_pitch_frame = res_pitch + psEnc->sCmn.frame_length; /* start of pitch LPC residual frame */
/****************************/
/* Voice Activity Detection */
/****************************/
ret =
SKP_Silk_VAD_GetSA_Q8(&psEnc->sCmn.sVAD, &psEnc->speech_activity_Q8,
&SNR_dB_Q7, sEncCtrl.input_quality_bands_Q15,
&sEncCtrl.input_tilt_Q15, pIn,
psEnc->sCmn.frame_length);
/*******************************************/
/* High-pass filtering of the input signal */
/*******************************************/
#if HIGH_PASS_INPUT
/* Variable high-pass filter */
SKP_Silk_HP_variable_cutoff_FIX(psEnc, &sEncCtrl, pIn_HP, pIn);
#else
SKP_memcpy(pIn_HP, pIn, psEnc->sCmn.frame_length * sizeof(int16_t));
#endif
#if SWITCH_TRANSITION_FILTERING
/* Ensure smooth bandwidth transitions */
SKP_Silk_LP_variable_cutoff(&psEnc->sCmn.sLP,
x_frame + psEnc->sCmn.la_shape, pIn_HP,
psEnc->sCmn.frame_length);
#else
SKP_memcpy(x_frame + psEnc->sCmn.la_shape, pIn_HP,
psEnc->sCmn.frame_length * sizeof(int16_t));
#endif
/*****************************************/
/* Find pitch lags, initial LPC analysis */
/*****************************************/
SKP_Silk_find_pitch_lags_FIX(psEnc, &sEncCtrl, res_pitch, x_frame);
/************************/
/* Noise shape analysis */
/************************/
SKP_Silk_noise_shape_analysis_FIX(psEnc, &sEncCtrl, res_pitch_frame,
x_frame);
/*****************************************/
/* Prefiltering for noise shaper */
/*****************************************/
SKP_Silk_prefilter_FIX(psEnc, &sEncCtrl, xfw, x_frame);
/***************************************************/
/* Find linear prediction coefficients (LPC + LTP) */
/***************************************************/
SKP_Silk_find_pred_coefs_FIX(psEnc, &sEncCtrl, res_pitch);
/****************************************/
/* Process gains */
/****************************************/
SKP_Silk_process_gains_FIX(psEnc, &sEncCtrl);
psEnc->sCmn.sigtype[psEnc->sCmn.nFramesInPayloadBuf] =
sEncCtrl.sCmn.sigtype;
psEnc->sCmn.QuantOffsetType[psEnc->sCmn.nFramesInPayloadBuf] =
sEncCtrl.sCmn.QuantOffsetType;
/****************************************/
/* Low Bitrate Redundant Encoding */
/****************************************/
nBytesLBRR = MAX_ARITHM_BYTES;
SKP_Silk_LBRR_encode_FIX(psEnc, &sEncCtrl, LBRRpayload, &nBytesLBRR,
xfw);
/*****************************************/
/* Noise shaping quantization */
/*****************************************/
psEnc->NoiseShapingQuantizer(&psEnc->sCmn, &sEncCtrl.sCmn, &psEnc->sNSQ,
xfw,
&psEnc->sCmn.q[psEnc->sCmn.
nFramesInPayloadBuf *
psEnc->sCmn.frame_length],
sEncCtrl.sCmn.NLSFInterpCoef_Q2,
sEncCtrl.PredCoef_Q12[0],
sEncCtrl.LTPCoef_Q14, sEncCtrl.AR2_Q13,
sEncCtrl.HarmShapeGain_Q14,
sEncCtrl.Tilt_Q14, sEncCtrl.LF_shp_Q14,
sEncCtrl.Gains_Q16, sEncCtrl.Lambda_Q10,
sEncCtrl.LTP_scale_Q14);
/**************************************************/
/* Convert speech activity into VAD and DTX flags */
/**************************************************/
if (psEnc->speech_activity_Q8 < SPEECH_ACTIVITY_DTX_THRES_Q8) {
psEnc->sCmn.vadFlag = NO_VOICE_ACTIVITY;
psEnc->sCmn.noSpeechCounter++;
if (psEnc->sCmn.noSpeechCounter > NO_SPEECH_FRAMES_BEFORE_DTX) {
psEnc->sCmn.inDTX = 1;
}
if (psEnc->sCmn.noSpeechCounter > MAX_CONSECUTIVE_DTX) {
psEnc->sCmn.noSpeechCounter = 0;
psEnc->sCmn.inDTX = 0;
}
} else {
psEnc->sCmn.noSpeechCounter = 0;
psEnc->sCmn.inDTX = 0;
psEnc->sCmn.vadFlag = VOICE_ACTIVITY;
}
/****************************************/
/* Initialize arithmetic coder */
/****************************************/
if (psEnc->sCmn.nFramesInPayloadBuf == 0) {
SKP_Silk_range_enc_init(&psEnc->sCmn.sRC);
psEnc->sCmn.nBytesInPayloadBuf = 0;
}
/****************************************/
/* Encode Parameters */
/****************************************/
if (psEnc->sCmn.bitstream_v == BIT_STREAM_V4) {
SKP_Silk_encode_parameters_v4(&psEnc->sCmn, &sEncCtrl.sCmn,
&psEnc->sCmn.sRC);
FrameTermination_CDF = SKP_Silk_FrameTermination_v4_CDF;
} else {
SKP_Silk_encode_parameters(&psEnc->sCmn, &sEncCtrl.sCmn,
&psEnc->sCmn.sRC,
&psEnc->sCmn.q[psEnc->sCmn.
nFramesInPayloadBuf *
psEnc->sCmn.
frame_length]);
FrameTermination_CDF = SKP_Silk_FrameTermination_CDF;
}
/****************************************/
/* Update Buffers and State */
/****************************************/
/* Update Input buffer */
SKP_memmove(psEnc->x_buf, &psEnc->x_buf[psEnc->sCmn.frame_length],
(psEnc->sCmn.frame_length +
psEnc->sCmn.la_shape) * sizeof(int16_t));
/* parameters needed for next frame */
psEnc->sCmn.prev_sigtype = sEncCtrl.sCmn.sigtype;
psEnc->sCmn.prevLag = sEncCtrl.sCmn.pitchL[NB_SUBFR - 1];
psEnc->sCmn.first_frame_after_reset = 0;
if (psEnc->sCmn.sRC.error) {
/* encoder returned error: clear payload buffer */
psEnc->sCmn.nFramesInPayloadBuf = 0;
} else {
psEnc->sCmn.nFramesInPayloadBuf++;
}
/****************************************/
/* finalize payload and copy to output */
/****************************************/
if (psEnc->sCmn.nFramesInPayloadBuf * FRAME_LENGTH_MS >=
psEnc->sCmn.PacketSize_ms) {
LBRR_idx = (psEnc->sCmn.oldest_LBRR_idx + 1) & LBRR_IDX_MASK;
/* Check if FEC information should be added */
frame_terminator = SKP_SILK_LAST_FRAME;
if (psEnc->sCmn.LBRR_buffer[LBRR_idx].usage ==
SKP_SILK_ADD_LBRR_TO_PLUS1) {
frame_terminator = SKP_SILK_LBRR_VER1;
}
if (psEnc->sCmn.LBRR_buffer[psEnc->sCmn.oldest_LBRR_idx].
usage == SKP_SILK_ADD_LBRR_TO_PLUS2) {
frame_terminator = SKP_SILK_LBRR_VER2;
LBRR_idx = psEnc->sCmn.oldest_LBRR_idx;
}
/* Add the frame termination info to stream */
SKP_Silk_range_encoder(&psEnc->sCmn.sRC, frame_terminator,
FrameTermination_CDF);
if (psEnc->sCmn.bitstream_v == BIT_STREAM_V4) {
/* Code excitation signal */
for (i = 0; i < psEnc->sCmn.nFramesInPayloadBuf; i++) {
SKP_Silk_encode_pulses(&psEnc->sCmn.sRC,
psEnc->sCmn.sigtype[i],
psEnc->sCmn.
QuantOffsetType[i],
&psEnc->sCmn.q[i *
psEnc->
sCmn.
frame_length],
psEnc->sCmn.
frame_length);
}
}
/* payload length so far */
SKP_Silk_range_coder_get_length(&psEnc->sCmn.sRC, &nBytes);
/* check that there is enough space in external output buffer, and move data */
if (*pnBytesOut >= nBytes) {
SKP_Silk_range_enc_wrap_up(&psEnc->sCmn.sRC);
SKP_memcpy(pCode, psEnc->sCmn.sRC.buffer,
nBytes * sizeof(uint8_t));
if (frame_terminator > SKP_SILK_MORE_FRAMES &&
*pnBytesOut >=
nBytes + psEnc->sCmn.LBRR_buffer[LBRR_idx].nBytes) {
/* Get old packet and add to payload. */
SKP_memcpy(&pCode[nBytes],
psEnc->sCmn.LBRR_buffer[LBRR_idx].
payload,
psEnc->sCmn.LBRR_buffer[LBRR_idx].
nBytes * sizeof(uint8_t));
nBytes +=
psEnc->sCmn.LBRR_buffer[LBRR_idx].nBytes;
}
*pnBytesOut = nBytes;
/* Update FEC buffer */
SKP_memcpy(psEnc->sCmn.
LBRR_buffer[psEnc->sCmn.oldest_LBRR_idx].
payload, LBRRpayload,
nBytesLBRR * sizeof(uint8_t));
psEnc->sCmn.LBRR_buffer[psEnc->sCmn.oldest_LBRR_idx].
nBytes = nBytesLBRR;
/* This line tells describes how FEC should be used */
psEnc->sCmn.LBRR_buffer[psEnc->sCmn.oldest_LBRR_idx].
usage = sEncCtrl.sCmn.LBRR_usage;
psEnc->sCmn.oldest_LBRR_idx =
(psEnc->sCmn.oldest_LBRR_idx + 1) & LBRR_IDX_MASK;
/* Reset number of frames in payload buffer */
psEnc->sCmn.nFramesInPayloadBuf = 0;
} else {
/* Not enough space: Payload will be discarded */
*pnBytesOut = 0;
nBytes = 0;
psEnc->sCmn.nFramesInPayloadBuf = 0;
ret = SKP_SILK_ENC_PAYLOAD_BUF_TOO_SHORT;
}
} else {
/* no payload for you this time */
*pnBytesOut = 0;
/* Encode that more frames follows */
frame_terminator = SKP_SILK_MORE_FRAMES;
SKP_Silk_range_encoder(&psEnc->sCmn.sRC, frame_terminator,
FrameTermination_CDF);
/* payload length so far */
SKP_Silk_range_coder_get_length(&psEnc->sCmn.sRC, &nBytes);
if (psEnc->sCmn.bitstream_v == BIT_STREAM_V4) {
/* Take into account the q signal that isnt in the bitstream yet */
nBytes += SKP_Silk_pulses_to_bytes(&psEnc->sCmn,
&psEnc->sCmn.
q[(psEnc->sCmn.
nFramesInPayloadBuf
-
1) *
psEnc->sCmn.
frame_length]);
}
}
/* Check for arithmetic coder errors */
if (psEnc->sCmn.sRC.error) {
ret = SKP_SILK_ENC_INTERNAL_ERROR;
}
/* simulate number of ms buffered in channel because of exceeding TargetRate */
assert((8 * 1000 *
((int64_t) nBytes -
(int64_t) psEnc->sCmn.nBytesInPayloadBuf)) ==
SKP_SAT32(8 * 1000 *
((int64_t) nBytes -
(int64_t) psEnc->sCmn.nBytesInPayloadBuf)));
assert(psEnc->sCmn.TargetRate_bps > 0);
psEnc->BufferedInChannel_ms +=
SKP_DIV32(8 * 1000 * (nBytes - psEnc->sCmn.nBytesInPayloadBuf),
psEnc->sCmn.TargetRate_bps);
psEnc->BufferedInChannel_ms -= FRAME_LENGTH_MS;
psEnc->BufferedInChannel_ms =
SKP_LIMIT(psEnc->BufferedInChannel_ms, 0, 100);
psEnc->sCmn.nBytesInPayloadBuf = nBytes;
if (psEnc->speech_activity_Q8 > WB_DETECT_ACTIVE_SPEECH_LEVEL_THRES_Q8) {
psEnc->sCmn.sSWBdetect.ActiveSpeech_ms =
SKP_ADD_POS_SAT32(psEnc->sCmn.sSWBdetect.ActiveSpeech_ms,
FRAME_LENGTH_MS);
}
return (ret);
}
/* Decode a frame */
SKP_int SKP_Silk_SDK_Decode(
void* decState, /* I/O: State */
SKP_SILK_SDK_DecControlStruct* decControl, /* I/O: Control structure */
SKP_int lostFlag, /* I: 0: no loss, 1 loss */
const SKP_uint8 *inData, /* I: Encoded input vector */
const SKP_int nBytesIn, /* I: Number of input Bytes */
SKP_int16 *samplesOut, /* O: Decoded output speech vector */
SKP_int16 *nSamplesOut /* I/O: Number of samples (vector/decoded) */
)
{
SKP_int ret = 0, used_bytes, prev_fs_kHz;
SKP_Silk_decoder_state *psDec;
SKP_int16 samplesOutInternal[ MAX_API_FS_KHZ * FRAME_LENGTH_MS ];
SKP_int16 *pSamplesOutInternal;
psDec = (SKP_Silk_decoder_state *)decState;
/* We need this buffer to have room for an internal frame */
pSamplesOutInternal = samplesOut;
if( psDec->fs_kHz * 1000 > decControl->API_sampleRate ) {
pSamplesOutInternal = samplesOutInternal;
}
/**********************************/
/* Test if first frame in payload */
/**********************************/
if( psDec->moreInternalDecoderFrames == 0 ) {
/* First Frame in Payload */
psDec->nFramesDecoded = 0; /* Used to count frames in packet */
}
if( psDec->moreInternalDecoderFrames == 0 && /* First frame in packet */
lostFlag == 0 && /* Not packet loss */
nBytesIn > MAX_ARITHM_BYTES ) { /* Too long payload */
/* Avoid trying to decode a too large packet */
lostFlag = 1;
ret = SKP_SILK_DEC_PAYLOAD_TOO_LARGE;
}
/* Save previous sample frequency */
prev_fs_kHz = psDec->fs_kHz;
/* Call decoder for one frame */
ret += SKP_Silk_decode_frame( psDec, pSamplesOutInternal, nSamplesOut, inData, nBytesIn,
lostFlag, &used_bytes );
if( used_bytes ) { /* Only Call if not a packet loss */
if( psDec->nBytesLeft > 0 && psDec->FrameTermination == SKP_SILK_MORE_FRAMES && psDec->nFramesDecoded < 5 ) {
/* We have more frames in the Payload */
psDec->moreInternalDecoderFrames = 1;
} else {
/* Last frame in Payload */
psDec->moreInternalDecoderFrames = 0;
psDec->nFramesInPacket = psDec->nFramesDecoded;
/* Track inband FEC usage */
if( psDec->vadFlag == VOICE_ACTIVITY ) {
if( psDec->FrameTermination == SKP_SILK_LAST_FRAME ) {
psDec->no_FEC_counter++;
if( psDec->no_FEC_counter > NO_LBRR_THRES ) {
psDec->inband_FEC_offset = 0;
}
} else if( psDec->FrameTermination == SKP_SILK_LBRR_VER1 ) {
psDec->inband_FEC_offset = 1; /* FEC info with 1 packet delay */
psDec->no_FEC_counter = 0;
} else if( psDec->FrameTermination == SKP_SILK_LBRR_VER2 ) {
psDec->inband_FEC_offset = 2; /* FEC info with 2 packets delay */
psDec->no_FEC_counter = 0;
}
}
}
}
if( MAX_API_FS_KHZ * 1000 < decControl->API_sampleRate ||
8000 > decControl->API_sampleRate ) {
ret = SKP_SILK_DEC_INVALID_SAMPLING_FREQUENCY;
return( ret );
}
/* Resample if needed */
if( psDec->fs_kHz * 1000 != decControl->API_sampleRate ) {
SKP_int16 samplesOut_tmp[ MAX_API_FS_KHZ * FRAME_LENGTH_MS ];
SKP_assert( psDec->fs_kHz <= MAX_API_FS_KHZ );
/* Copy to a tmp buffer as the resampling writes to samplesOut */
SKP_memcpy( samplesOut_tmp, pSamplesOutInternal, *nSamplesOut * sizeof( SKP_int16 ) );
/* (Re-)initialize resampler state when switching internal sampling frequency */
if( prev_fs_kHz != psDec->fs_kHz || psDec->prev_API_sampleRate != decControl->API_sampleRate ) {
ret = SKP_Silk_resampler_init( &psDec->resampler_state, SKP_SMULBB( psDec->fs_kHz, 1000 ), decControl->API_sampleRate );
}
/* Resample the output to API_sampleRate */
ret += SKP_Silk_resampler( &psDec->resampler_state, samplesOut, samplesOut_tmp, *nSamplesOut );
/* Update the number of output samples */
*nSamplesOut = SKP_DIV32( ( SKP_int32 )*nSamplesOut * decControl->API_sampleRate, psDec->fs_kHz * 1000 );
} else if( prev_fs_kHz * 1000 > decControl->API_sampleRate ) {
SKP_memcpy( samplesOut, pSamplesOutInternal, *nSamplesOut * sizeof( SKP_int16 ) );
}
psDec->prev_API_sampleRate = decControl->API_sampleRate;
/* Copy all parameters that are needed out of internal structure to the control stucture */
decControl->frameSize = (SKP_uint16)( decControl->API_sampleRate / 50 ) ;
decControl->framesPerPacket = ( SKP_int )psDec->nFramesInPacket;
decControl->inBandFECOffset = ( SKP_int )psDec->inband_FEC_offset;
decControl->moreInternalDecoderFrames = ( SKP_int )psDec->moreInternalDecoderFrames;
return ret;
}
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 );
}
SKP_int SKP_Silk_SDK_Encode(
void *encState, /* I/O: State */
SKP_Silk_EncodeControlStruct *encControl, /* I: Control structure */
const SKP_int16 *samplesIn, /* I: Speech sample input vector */
SKP_int nSamplesIn, /* I: Number of samples in input vector */
ec_enc *psRangeEnc, /* I/O Compressor data structure */
SKP_int32 *nBytesOut, /* I/O: Number of bytes in payload (input: Max bytes) */
const SKP_int prefillFlag /* I: Flag to indicate prefilling buffers no coding */
)
{
SKP_int tmp_payloadSize_ms, tmp_complexity, ret = 0;
SKP_int nSamplesToBuffer, nBlocksOf10ms, nSamplesFromInput = 0;
SKP_Silk_encoder_state_Fxx *psEnc = ( SKP_Silk_encoder_state_Fxx* )encState;
ret = process_enc_control_struct( psEnc, encControl );
nBlocksOf10ms = SKP_DIV32( 100 * nSamplesIn, psEnc->sCmn.API_fs_Hz );
if( prefillFlag ) {
/* Only accept input length of 10 ms */
if( nBlocksOf10ms != 1 ) {
ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
SKP_assert( 0 );
return( ret );
}
/* Reset Encoder */
if( ret = SKP_Silk_init_encoder_Fxx( psEnc ) ) {
SKP_assert( 0 );
}
tmp_payloadSize_ms = encControl->payloadSize_ms;
encControl->payloadSize_ms = 10;
tmp_complexity = encControl->complexity;
encControl->complexity = 0;
ret = process_enc_control_struct( psEnc, encControl );
psEnc->sCmn.prefillFlag = 1;
} else {
/* Only accept input lengths that are a multiple of 10 ms */
if( nBlocksOf10ms * psEnc->sCmn.API_fs_Hz != 100 * nSamplesIn || nSamplesIn < 0 ) {
ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
SKP_assert( 0 );
return( ret );
}
/* Make sure no more than one packet can be produced */
if( 1000 * (SKP_int32)nSamplesIn > psEnc->sCmn.PacketSize_ms * psEnc->sCmn.API_fs_Hz ) {
ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
SKP_assert( 0 );
return( ret );
}
}
/* Input buffering/resampling and encoding */
while( 1 ) {
nSamplesToBuffer = psEnc->sCmn.frame_length - psEnc->sCmn.inputBufIx;
if( psEnc->sCmn.API_fs_Hz == SKP_SMULBB( 1000, psEnc->sCmn.fs_kHz ) ) {
nSamplesToBuffer = SKP_min_int( nSamplesToBuffer, nSamplesIn );
nSamplesFromInput = nSamplesToBuffer;
/* Copy to buffer */
SKP_memcpy( &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput * sizeof( SKP_int16 ) );
} else {
nSamplesToBuffer = SKP_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->sCmn.fs_kHz );
nSamplesFromInput = SKP_DIV32_16( nSamplesToBuffer * psEnc->sCmn.API_fs_Hz, psEnc->sCmn.fs_kHz * 1000 );
/* Resample and write to buffer */
ret += SKP_Silk_resampler( &psEnc->sCmn.resampler_state, &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput );
}
samplesIn += nSamplesFromInput;
nSamplesIn -= nSamplesFromInput;
psEnc->sCmn.inputBufIx += nSamplesToBuffer;
/* Silk encoder */
if( psEnc->sCmn.inputBufIx >= psEnc->sCmn.frame_length ) {
SKP_assert( psEnc->sCmn.inputBufIx == psEnc->sCmn.frame_length );
/* Enough data in input buffer, so encode */
if( ( ret = SKP_Silk_encode_frame_Fxx( psEnc, nBytesOut, psRangeEnc ) ) != 0 ) {
SKP_assert( 0 );
}
psEnc->sCmn.inputBufIx = 0;
psEnc->sCmn.controlled_since_last_payload = 0;
if( nSamplesIn == 0 ) {
break;
}
} else {
break;
}
}
if( prefillFlag ) {
encControl->payloadSize_ms = tmp_payloadSize_ms;
encControl->complexity = tmp_complexity;
ret = process_enc_control_struct( psEnc, encControl );
psEnc->sCmn.prefillFlag = 0;
}
return ret;
}
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));
}
