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 /**********************************************************/ 36 /* Core decoder. Performs inverse NSQ operation LTP + LPC */ 37 /**********************************************************/ 38 void silk_decode_core( 39 silk_decoder_state *psDec, /* I/O Decoder state */ 40 silk_decoder_control *psDecCtrl, /* I Decoder control */ 41 opus_int16 xq[], /* O Decoded speech */ 42 const opus_int16 pulses[ MAX_FRAME_LENGTH ], /* I Pulse signal */ 43 int arch /* I Run-time architecture */ 44 ) 45 { 46 opus_int i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType; 47 opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ]; 48 VARDECL( opus_int16, sLTP ); 49 VARDECL( opus_int32, sLTP_Q15 ); 50 opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10; 51 opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14; 52 VARDECL( opus_int32, res_Q14 ); 53 VARDECL( opus_int32, sLPC_Q14 ); 54 SAVE_STACK; 55 56 silk_assert( psDec->prev_gain_Q16 != 0 ); 57 58 ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 ); 59 ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 ); 60 ALLOC( res_Q14, psDec->subfr_length, opus_int32 ); 61 ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 ); 62 63 offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ]; 64 65 if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) { 66 NLSF_interpolation_flag = 1; 67 } else { 68 NLSF_interpolation_flag = 0; 69 } 70 71 /* Decode excitation */ 72 rand_seed = psDec->indices.Seed; 73 for( i = 0; i < psDec->frame_length; i++ ) { 74 rand_seed = silk_RAND( rand_seed ); 75 psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 ); 76 if( psDec->exc_Q14[ i ] > 0 ) { 77 psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4; 78 } else 79 if( psDec->exc_Q14[ i ] < 0 ) { 80 psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4; 81 } 82 psDec->exc_Q14[ i ] += offset_Q10 << 4; 83 if( rand_seed < 0 ) { 84 psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ]; 85 } 86 87 rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] ); 88 } 89 90 /* Copy LPC state */ 91 silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) ); 92 93 pexc_Q14 = psDec->exc_Q14; 94 pxq = xq; 95 sLTP_buf_idx = psDec->ltp_mem_length; 96 /* Loop over subframes */ 97 for( k = 0; k < psDec->nb_subfr; k++ ) { 98 pres_Q14 = res_Q14; 99 A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ]; 100 101 /* Preload LPC coeficients to array on stack. Gives small performance gain */ 102 silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) ); 103 B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ]; 104 signalType = psDec->indices.signalType; 105 106 Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 ); 107 inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 ); 108 109 /* Calculate gain adjustment factor */ 110 if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) { 111 gain_adj_Q16 = silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 ); 112 113 /* Scale short term state */ 114 for( i = 0; i < MAX_LPC_ORDER; i++ ) { 115 sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] ); 116 } 117 } else { 118 gain_adj_Q16 = (opus_int32)1 << 16; 119 } 120 121 /* Save inv_gain */ 122 silk_assert( inv_gain_Q31 != 0 ); 123 psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ]; 124 125 /* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */ 126 if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED && 127 psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) { 128 129 silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) ); 130 B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 ); 131 132 signalType = TYPE_VOICED; 133 psDecCtrl->pitchL[ k ] = psDec->lagPrev; 134 } 135 136 if( signalType == TYPE_VOICED ) { 137 /* Voiced */ 138 lag = psDecCtrl->pitchL[ k ]; 139 140 /* Re-whitening */ 141 if( k == 0 || ( k == 2 && NLSF_interpolation_flag ) ) { 142 /* Rewhiten with new A coefs */ 143 start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2; 144 silk_assert( start_idx > 0 ); 145 146 if( k == 2 ) { 147 silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) ); 148 } 149 150 silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ], 151 A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order, arch ); 152 153 /* After rewhitening the LTP state is unscaled */ 154 if( k == 0 ) { 155 /* Do LTP downscaling to reduce inter-packet dependency */ 156 inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 ); 157 } 158 for( i = 0; i < lag + LTP_ORDER/2; i++ ) { 159 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] ); 160 } 161 } else { 162 /* Update LTP state when Gain changes */ 163 if( gain_adj_Q16 != (opus_int32)1 << 16 ) { 164 for( i = 0; i < lag + LTP_ORDER/2; i++ ) { 165 sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] ); 166 } 167 } 168 } 169 } 170 171 /* Long-term prediction */ 172 if( signalType == TYPE_VOICED ) { 173 /* Set up pointer */ 174 pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ]; 175 for( i = 0; i < psDec->subfr_length; i++ ) { 176 /* Unrolled loop */ 177 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ 178 LTP_pred_Q13 = 2; 179 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] ); 180 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] ); 181 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] ); 182 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] ); 183 LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] ); 184 pred_lag_ptr++; 185 186 /* Generate LPC excitation */ 187 pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 ); 188 189 /* Update states */ 190 sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 ); 191 sLTP_buf_idx++; 192 } 193 } else { 194 pres_Q14 = pexc_Q14; 195 } 196 197 for( i = 0; i < psDec->subfr_length; i++ ) { 198 /* Short-term prediction */ 199 silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 ); 200 /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ 201 LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 ); 202 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] ); 203 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] ); 204 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] ); 205 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] ); 206 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] ); 207 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] ); 208 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] ); 209 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] ); 210 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] ); 211 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] ); 212 if( psDec->LPC_order == 16 ) { 213 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] ); 214 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] ); 215 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] ); 216 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] ); 217 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] ); 218 LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] ); 219 } 220 221 /* Add prediction to LPC excitation */ 222 sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_SAT32( pres_Q14[ i ], silk_LSHIFT_SAT32( LPC_pred_Q10, 4 ) ); 223 224 /* Scale with gain */ 225 pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) ); 226 } 227 228 /* Update LPC filter state */ 229 silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) ); 230 pexc_Q14 += psDec->subfr_length; 231 pxq += psDec->subfr_length; 232 } 233 234 /* Save LPC state */ 235 silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) ); 236 RESTORE_STACK; 237 } 238
