1 /*********************************************************************** 2 Copyright (c) 2006-2011, Skype Limited. All rights reserved. 3 Redistribution and use in source and binary forms, with or without 4 modification, are permitted provided that the following conditions 5 are met: 6 - Redistributions of source code must retain the above copyright notice, 7 this list of conditions and the following disclaimer. 8 - Redistributions in binary form must reproduce the above copyright 9 notice, this list of conditions and the following disclaimer in the 10 documentation and/or other materials provided with the distribution. 11 - Neither the name of Internet Society, IETF or IETF Trust, nor the 12 names of specific contributors, may be used to endorse or promote 13 products derived from this software without specific prior written 14 permission. 15 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 19 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 POSSIBILITY OF SUCH DAMAGE. 26 ***********************************************************************/ 27 28 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #include "main.h" 33 #include "stack_alloc.h" 34 35 /* Generates excitation for CNG LPC synthesis */ 36 static inline void silk_CNG_exc( 37 opus_int32 residual_Q10[], /* O CNG residual signal Q10 */ 38 opus_int32 exc_buf_Q14[], /* I Random samples buffer Q10 */ 39 opus_int32 Gain_Q16, /* I Gain to apply */ 40 opus_int length, /* I Length */ 41 opus_int32 *rand_seed /* I/O Seed to random index generator */ 42 ) 43 { 44 opus_int32 seed; 45 opus_int i, idx, exc_mask; 46 47 exc_mask = CNG_BUF_MASK_MAX; 48 while( exc_mask > length ) { 49 exc_mask = silk_RSHIFT( exc_mask, 1 ); 50 } 51 52 seed = *rand_seed; 53 for( i = 0; i < length; i++ ) { 54 seed = silk_RAND( seed ); 55 idx = (opus_int)( silk_RSHIFT( seed, 24 ) & exc_mask ); 56 silk_assert( idx >= 0 ); 57 silk_assert( idx <= CNG_BUF_MASK_MAX ); 58 residual_Q10[ i ] = (opus_int16)silk_SAT16( silk_SMULWW( exc_buf_Q14[ idx ], Gain_Q16 >> 4 ) ); 59 } 60 *rand_seed = seed; 61 } 62 63 void silk_CNG_Reset( 64 silk_decoder_state *psDec /* I/O Decoder state */ 65 ) 66 { 67 opus_int i, NLSF_step_Q15, NLSF_acc_Q15; 68 69 NLSF_step_Q15 = silk_DIV32_16( silk_int16_MAX, psDec->LPC_order + 1 ); 70 NLSF_acc_Q15 = 0; 71 for( i = 0; i < psDec->LPC_order; i++ ) { 72 NLSF_acc_Q15 += NLSF_step_Q15; 73 psDec->sCNG.CNG_smth_NLSF_Q15[ i ] = NLSF_acc_Q15; 74 } 75 psDec->sCNG.CNG_smth_Gain_Q16 = 0; 76 psDec->sCNG.rand_seed = 3176576; 77 } 78 79 /* Updates CNG estimate, and applies the CNG when packet was lost */ 80 void silk_CNG( 81 silk_decoder_state *psDec, /* I/O Decoder state */ 82 silk_decoder_control *psDecCtrl, /* I/O Decoder control */ 83 opus_int16 frame[], /* I/O Signal */ 84 opus_int length /* I Length of residual */ 85 ) 86 { 87 opus_int i, subfr; 88 opus_int32 sum_Q6, max_Gain_Q16; 89 opus_int16 A_Q12[ MAX_LPC_ORDER ]; 90 silk_CNG_struct *psCNG = &psDec->sCNG; 91 SAVE_STACK; 92 93 if( psDec->fs_kHz != psCNG->fs_kHz ) { 94 /* Reset state */ 95 silk_CNG_Reset( psDec ); 96 97 psCNG->fs_kHz = psDec->fs_kHz; 98 } 99 if( psDec->lossCnt == 0 && psDec->prevSignalType == TYPE_NO_VOICE_ACTIVITY ) { 100 /* Update CNG parameters */ 101 102 /* Smoothing of LSF's */ 103 for( i = 0; i < psDec->LPC_order; i++ ) { 104 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 ); 105 } 106 /* Find the subframe with the highest gain */ 107 max_Gain_Q16 = 0; 108 subfr = 0; 109 for( i = 0; i < psDec->nb_subfr; i++ ) { 110 if( psDecCtrl->Gains_Q16[ i ] > max_Gain_Q16 ) { 111 max_Gain_Q16 = psDecCtrl->Gains_Q16[ i ]; 112 subfr = i; 113 } 114 } 115 /* Update CNG excitation buffer with excitation from this subframe */ 116 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 ) ); 117 silk_memcpy( psCNG->CNG_exc_buf_Q14, &psDec->exc_Q14[ subfr * psDec->subfr_length ], psDec->subfr_length * sizeof( opus_int32 ) ); 118 119 /* Smooth gains */ 120 for( i = 0; i < psDec->nb_subfr; i++ ) { 121 psCNG->CNG_smth_Gain_Q16 += silk_SMULWB( psDecCtrl->Gains_Q16[ i ] - psCNG->CNG_smth_Gain_Q16, CNG_GAIN_SMTH_Q16 ); 122 } 123 } 124 125 /* Add CNG when packet is lost or during DTX */ 126 if( psDec->lossCnt ) { 127 VARDECL( opus_int32, CNG_sig_Q10 ); 128 129 ALLOC( CNG_sig_Q10, length + MAX_LPC_ORDER, opus_int32 ); 130 131 /* Generate CNG excitation */ 132 silk_CNG_exc( CNG_sig_Q10 + MAX_LPC_ORDER, psCNG->CNG_exc_buf_Q14, psCNG->CNG_smth_Gain_Q16, length, &psCNG->rand_seed ); 133 134 /* Convert CNG NLSF to filter representation */ 135 silk_NLSF2A( A_Q12, psCNG->CNG_smth_NLSF_Q15, psDec->LPC_order ); 136 137 /* Generate CNG signal, by synthesis filtering */ 138 silk_memcpy( CNG_sig_Q10, psCNG->CNG_synth_state, MAX_LPC_ORDER * sizeof( opus_int32 ) ); 139 for( i = 0; i < length; i++ ) { 140 silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 ); 141 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ 142 sum_Q6 = silk_RSHIFT( psDec->LPC_order, 1 ); 143 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 1 ], A_Q12[ 0 ] ); 144 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 2 ], A_Q12[ 1 ] ); 145 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 3 ], A_Q12[ 2 ] ); 146 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 4 ], A_Q12[ 3 ] ); 147 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 5 ], A_Q12[ 4 ] ); 148 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 6 ], A_Q12[ 5 ] ); 149 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 7 ], A_Q12[ 6 ] ); 150 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 8 ], A_Q12[ 7 ] ); 151 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 9 ], A_Q12[ 8 ] ); 152 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 10 ], A_Q12[ 9 ] ); 153 if( psDec->LPC_order == 16 ) { 154 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 11 ], A_Q12[ 10 ] ); 155 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 12 ], A_Q12[ 11 ] ); 156 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 13 ], A_Q12[ 12 ] ); 157 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 14 ], A_Q12[ 13 ] ); 158 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 15 ], A_Q12[ 14 ] ); 159 sum_Q6 = silk_SMLAWB( sum_Q6, CNG_sig_Q10[ MAX_LPC_ORDER + i - 16 ], A_Q12[ 15 ] ); 160 } 161 162 /* Update states */ 163 CNG_sig_Q10[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT( CNG_sig_Q10[ MAX_LPC_ORDER + i ], sum_Q6, 4 ); 164 165 frame[ i ] = silk_ADD_SAT16( frame[ i ], silk_RSHIFT_ROUND( sum_Q6, 6 ) ); 166 } 167 silk_memcpy( psCNG->CNG_synth_state, &CNG_sig_Q10[ length ], MAX_LPC_ORDER * sizeof( opus_int32 ) ); 168 } else { 169 silk_memset( psCNG->CNG_synth_state, 0, psDec->LPC_order * sizeof( opus_int32 ) ); 170 } 171 RESTORE_STACK; 172 } 173
