| /*********************************************************************** |
| Copyright (c) 2006-2011, Skype Limited. All rights reserved. |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| - Redistributions of source code must retain the above copyright notice, |
| this list of conditions and the following disclaimer. |
| - Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| - Neither the name of Internet Society, IETF or IETF Trust, nor the |
| names of specific contributors, may be used to endorse or promote |
| products derived from this software without specific prior written |
| permission. |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. |
| ***********************************************************************/ |
| |
| #ifdef HAVE_CONFIG_H |
| #include "config.h" |
| #endif |
| |
| #include "main.h" |
| |
| /* Generates excitation for CNG LPC synthesis */ |
| static inline void silk_CNG_exc( |
| opus_int32 residual_Q10[], /* O CNG residual signal Q10 */ |
| opus_int32 exc_buf_Q14[], /* I Random samples buffer Q10 */ |
| opus_int32 Gain_Q16, /* I Gain to apply */ |
| opus_int length, /* I Length */ |
| opus_int32 *rand_seed /* I/O Seed to random index generator */ |
| ) |
| { |
| opus_int32 seed; |
| opus_int i, idx, exc_mask; |
| |
| exc_mask = CNG_BUF_MASK_MAX; |
| while( exc_mask > length ) { |
| exc_mask = silk_RSHIFT( exc_mask, 1 ); |
| } |
| |
| seed = *rand_seed; |
| for( i = 0; i < length; i++ ) { |
| seed = silk_RAND( seed ); |
| idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask ); |
| silk_assert( idx >= 0 ); |
| silk_assert( idx <= CNG_BUF_MASK_MAX ); |
| residual_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) ); |
| } |
| *rand_seed = seed; |
| } |
| |
| void silk_CNG_Reset( |
| silk_decoder_state *psDec /* I/O Decoder state */ |
| ) |
| { |
| opus_int i, NLSF_step_Q15, NLSF_acc_Q15; |
| |
| NLSF_step_Q15 = silk_DIV32_16( silk_int16_MAX, psDec->LPC_order + 1 ); |
| NLSF_acc_Q15 = 0; |
| for( i = 0; i < psDec->LPC_order; i++ ) { |
| NLSF_acc_Q15 += NLSF_step_Q15; |
| psDec->sCNG.CNG_smth_NLSF_Q15[ i ] = NLSF_acc_Q15; |
| } |
| psDec->sCNG.CNG_smth_Gain_Q16 = 0; |
| psDec->sCNG.rand_seed = 3176576; |
| } |
| |
| /* Updates CNG estimate, and applies the CNG when packet was lost */ |
| void silk_CNG( |
| silk_decoder_state *psDec, /* I/O Decoder state */ |
| silk_decoder_control *psDecCtrl, /* I/O Decoder control */ |
| opus_int16 frame[], /* I/O Signal */ |
| opus_int length /* I Length of residual */ |
| ) |
| { |
| opus_int i, subfr; |
| opus_int32 sum_Q6, max_Gain_Q16; |
| opus_int16 A_Q12[ MAX_LPC_ORDER ]; |
| opus_int32 CNG_sig_Q10[ MAX_FRAME_LENGTH + MAX_LPC_ORDER ]; |
| silk_CNG_struct *psCNG = &psDec->sCNG; |
| |
| if( psDec->fs_kHz != psCNG->fs_kHz ) { |
| /* Reset state */ |
| silk_CNG_Reset( psDec ); |
| |
| psCNG->fs_kHz = psDec->fs_kHz; |
| } |
| if( psDec->lossCnt == 0 && psDec->prevSignalType == TYPE_NO_VOICE_ACTIVITY ) { |
| /* Update CNG parameters */ |
| |
| /* Smoothing of LSF's */ |
| for( i = 0; i < psDec->LPC_order; i++ ) { |
| psCNG->CNG_smth_NLSF_Q15[ i ] += silk_SMULWB( (opus_int32)psDec->prevNLSF_Q15[ i ] - (opus_int32)psCNG->CNG_smth_NLSF_Q15[ i ], CNG_NLSF_SMTH_Q16 ); |
| } |
| /* Find the subframe with the highest gain */ |
| max_Gain_Q16 = 0; |
| subfr = 0; |
| for( i = 0; i < psDec->nb_subfr; i++ ) { |
| if( psDecCtrl->Gains_Q16[ i ] > max_Gain_Q16 ) { |
| max_Gain_Q16 = psDecCtrl->Gains_Q16[ i ]; |
| subfr = i; |
| } |
| } |
| /* Update CNG excitation buffer with excitation from this subframe */ |
| silk_memmove( &psCNG->CNG_exc_buf_Q14[ psDec->subfr_length ], psCNG->CNG_exc_buf_Q14, ( psDec->nb_subfr - 1 ) * psDec->subfr_length * sizeof( opus_int32 ) ); |
| silk_memcpy( psCNG->CNG_exc_buf_Q14, &psDec->exc_Q14[ subfr * psDec->subfr_length ], psDec->subfr_length * sizeof( opus_int32 ) ); |
| |
| /* Smooth gains */ |
| for( i = 0; i < psDec->nb_subfr; i++ ) { |
| psCNG->CNG_smth_Gain_Q16 += silk_SMULWB( psDecCtrl->Gains_Q16[ i ] - psCNG->CNG_smth_Gain_Q16, CNG_GAIN_SMTH_Q16 ); |
| } |
| } |
| |
| /* Add CNG when packet is lost or during DTX */ |
| if( psDec->lossCnt ) { |
| |
| /* Generate CNG excitation */ |
| silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, psCNG->CNG_smth_Gain_Q16, length, &psCNG->rand_seed ); |
| |
| /* Convert CNG NLSF to filter representation */ |
| silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order ); |
| |
| /* Generate CNG signal, by synthesis filtering */ |
| silk_memcpy( CNG_sig_Q10, psCNG->CNG_synth_state, MAX_LPC_ORDER * sizeof( opus_int32 ) ); |
| for( i = 0; i < length; i++ ) { |
| silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 ); |
| /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ |
| sum_Q6 = silk_RSHIFT( psDec->LPC_order, 1 ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 1 ], A_Q12[ 0 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 2 ], A_Q12[ 1 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 3 ], A_Q12[ 2 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 4 ], A_Q12[ 3 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 5 ], A_Q12[ 4 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 6 ], A_Q12[ 5 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 7 ], A_Q12[ 6 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 8 ], A_Q12[ 7 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 9 ], A_Q12[ 8 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] ); |
| if( psDec->LPC_order == 16 ) { |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 11 ], A_Q12[ 10 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 12 ], A_Q12[ 11 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 13 ], A_Q12[ 12 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 14 ], A_Q12[ 13 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 15 ], A_Q12[ 14 ] ); |
| sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 16 ], A_Q12[ 15 ] ); |
| } |
| |
| /* Update states */ |
| CNG_sig_Q10[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT( CNG_sig_Q10[ MAX_LPC_ORDER + i ], sum_Q6, 4 ); |
| |
| frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( sum_Q6, 6 ) ); |
| } |
| silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q10[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) ); |
| } else { |
| silk_memset( psCNG->CNG_synth_state, 0, psDec->LPC_order * sizeof( opus_int32 ) ); |
| } |
| } |
