Alexandre Lision | 744f742 | 2013-09-25 11:39:37 -0400 | [diff] [blame] | 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_int pulses[ MAX_FRAME_LENGTH ] /* I Pulse signal */ |
| 43 | ) |
| 44 | { |
| 45 | opus_int i, k, lag = 0, start_idx, sLTP_buf_idx, NLSF_interpolation_flag, signalType; |
| 46 | opus_int16 *A_Q12, *B_Q14, *pxq, A_Q12_tmp[ MAX_LPC_ORDER ]; |
| 47 | VARDECL( opus_int16, sLTP ); |
| 48 | VARDECL( opus_int32, sLTP_Q15 ); |
| 49 | opus_int32 LTP_pred_Q13, LPC_pred_Q10, Gain_Q10, inv_gain_Q31, gain_adj_Q16, rand_seed, offset_Q10; |
| 50 | opus_int32 *pred_lag_ptr, *pexc_Q14, *pres_Q14; |
| 51 | VARDECL( opus_int32, res_Q14 ); |
| 52 | VARDECL( opus_int32, sLPC_Q14 ); |
| 53 | SAVE_STACK; |
| 54 | |
| 55 | silk_assert( psDec->prev_gain_Q16 != 0 ); |
| 56 | |
| 57 | ALLOC( sLTP, psDec->ltp_mem_length, opus_int16 ); |
| 58 | ALLOC( sLTP_Q15, psDec->ltp_mem_length + psDec->frame_length, opus_int32 ); |
| 59 | ALLOC( res_Q14, psDec->subfr_length, opus_int32 ); |
| 60 | ALLOC( sLPC_Q14, psDec->subfr_length + MAX_LPC_ORDER, opus_int32 ); |
| 61 | |
| 62 | offset_Q10 = silk_Quantization_Offsets_Q10[ psDec->indices.signalType >> 1 ][ psDec->indices.quantOffsetType ]; |
| 63 | |
| 64 | if( psDec->indices.NLSFInterpCoef_Q2 < 1 << 2 ) { |
| 65 | NLSF_interpolation_flag = 1; |
| 66 | } else { |
| 67 | NLSF_interpolation_flag = 0; |
| 68 | } |
| 69 | |
| 70 | /* Decode excitation */ |
| 71 | rand_seed = psDec->indices.Seed; |
| 72 | for( i = 0; i < psDec->frame_length; i++ ) { |
| 73 | rand_seed = silk_RAND( rand_seed ); |
| 74 | psDec->exc_Q14[ i ] = silk_LSHIFT( (opus_int32)pulses[ i ], 14 ); |
| 75 | if( psDec->exc_Q14[ i ] > 0 ) { |
| 76 | psDec->exc_Q14[ i ] -= QUANT_LEVEL_ADJUST_Q10 << 4; |
| 77 | } else |
| 78 | if( psDec->exc_Q14[ i ] < 0 ) { |
| 79 | psDec->exc_Q14[ i ] += QUANT_LEVEL_ADJUST_Q10 << 4; |
| 80 | } |
| 81 | psDec->exc_Q14[ i ] += offset_Q10 << 4; |
| 82 | if( rand_seed < 0 ) { |
| 83 | psDec->exc_Q14[ i ] = -psDec->exc_Q14[ i ]; |
| 84 | } |
| 85 | |
| 86 | rand_seed = silk_ADD32_ovflw( rand_seed, pulses[ i ] ); |
| 87 | } |
| 88 | |
| 89 | /* Copy LPC state */ |
| 90 | silk_memcpy( sLPC_Q14, psDec->sLPC_Q14_buf, MAX_LPC_ORDER * sizeof( opus_int32 ) ); |
| 91 | |
| 92 | pexc_Q14 = psDec->exc_Q14; |
| 93 | pxq = xq; |
| 94 | sLTP_buf_idx = psDec->ltp_mem_length; |
| 95 | /* Loop over subframes */ |
| 96 | for( k = 0; k < psDec->nb_subfr; k++ ) { |
| 97 | pres_Q14 = res_Q14; |
| 98 | A_Q12 = psDecCtrl->PredCoef_Q12[ k >> 1 ]; |
| 99 | |
| 100 | /* Preload LPC coeficients to array on stack. Gives small performance gain */ |
| 101 | silk_memcpy( A_Q12_tmp, A_Q12, psDec->LPC_order * sizeof( opus_int16 ) ); |
| 102 | B_Q14 = &psDecCtrl->LTPCoef_Q14[ k * LTP_ORDER ]; |
| 103 | signalType = psDec->indices.signalType; |
| 104 | |
| 105 | Gain_Q10 = silk_RSHIFT( psDecCtrl->Gains_Q16[ k ], 6 ); |
| 106 | inv_gain_Q31 = silk_INVERSE32_varQ( psDecCtrl->Gains_Q16[ k ], 47 ); |
| 107 | |
| 108 | /* Calculate gain adjustment factor */ |
| 109 | if( psDecCtrl->Gains_Q16[ k ] != psDec->prev_gain_Q16 ) { |
| 110 | gain_adj_Q16 = silk_DIV32_varQ( psDec->prev_gain_Q16, psDecCtrl->Gains_Q16[ k ], 16 ); |
| 111 | |
| 112 | /* Scale short term state */ |
| 113 | for( i = 0; i < MAX_LPC_ORDER; i++ ) { |
| 114 | sLPC_Q14[ i ] = silk_SMULWW( gain_adj_Q16, sLPC_Q14[ i ] ); |
| 115 | } |
| 116 | } else { |
| 117 | gain_adj_Q16 = (opus_int32)1 << 16; |
| 118 | } |
| 119 | |
| 120 | /* Save inv_gain */ |
| 121 | silk_assert( inv_gain_Q31 != 0 ); |
| 122 | psDec->prev_gain_Q16 = psDecCtrl->Gains_Q16[ k ]; |
| 123 | |
| 124 | /* Avoid abrupt transition from voiced PLC to unvoiced normal decoding */ |
| 125 | if( psDec->lossCnt && psDec->prevSignalType == TYPE_VOICED && |
| 126 | psDec->indices.signalType != TYPE_VOICED && k < MAX_NB_SUBFR/2 ) { |
| 127 | |
| 128 | silk_memset( B_Q14, 0, LTP_ORDER * sizeof( opus_int16 ) ); |
| 129 | B_Q14[ LTP_ORDER/2 ] = SILK_FIX_CONST( 0.25, 14 ); |
| 130 | |
| 131 | signalType = TYPE_VOICED; |
| 132 | psDecCtrl->pitchL[ k ] = psDec->lagPrev; |
| 133 | } |
| 134 | |
| 135 | if( signalType == TYPE_VOICED ) { |
| 136 | /* Voiced */ |
| 137 | lag = psDecCtrl->pitchL[ k ]; |
| 138 | |
| 139 | /* Re-whitening */ |
| 140 | if( k == 0 || ( k == 2 && NLSF_interpolation_flag ) ) { |
| 141 | /* Rewhiten with new A coefs */ |
| 142 | start_idx = psDec->ltp_mem_length - lag - psDec->LPC_order - LTP_ORDER / 2; |
| 143 | silk_assert( start_idx > 0 ); |
| 144 | |
| 145 | if( k == 2 ) { |
| 146 | silk_memcpy( &psDec->outBuf[ psDec->ltp_mem_length ], xq, 2 * psDec->subfr_length * sizeof( opus_int16 ) ); |
| 147 | } |
| 148 | |
| 149 | silk_LPC_analysis_filter( &sLTP[ start_idx ], &psDec->outBuf[ start_idx + k * psDec->subfr_length ], |
| 150 | A_Q12, psDec->ltp_mem_length - start_idx, psDec->LPC_order ); |
| 151 | |
| 152 | /* After rewhitening the LTP state is unscaled */ |
| 153 | if( k == 0 ) { |
| 154 | /* Do LTP downscaling to reduce inter-packet dependency */ |
| 155 | inv_gain_Q31 = silk_LSHIFT( silk_SMULWB( inv_gain_Q31, psDecCtrl->LTP_scale_Q14 ), 2 ); |
| 156 | } |
| 157 | for( i = 0; i < lag + LTP_ORDER/2; i++ ) { |
| 158 | sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWB( inv_gain_Q31, sLTP[ psDec->ltp_mem_length - i - 1 ] ); |
| 159 | } |
| 160 | } else { |
| 161 | /* Update LTP state when Gain changes */ |
| 162 | if( gain_adj_Q16 != (opus_int32)1 << 16 ) { |
| 163 | for( i = 0; i < lag + LTP_ORDER/2; i++ ) { |
| 164 | sLTP_Q15[ sLTP_buf_idx - i - 1 ] = silk_SMULWW( gain_adj_Q16, sLTP_Q15[ sLTP_buf_idx - i - 1 ] ); |
| 165 | } |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | /* Long-term prediction */ |
| 171 | if( signalType == TYPE_VOICED ) { |
| 172 | /* Set up pointer */ |
| 173 | pred_lag_ptr = &sLTP_Q15[ sLTP_buf_idx - lag + LTP_ORDER / 2 ]; |
| 174 | for( i = 0; i < psDec->subfr_length; i++ ) { |
| 175 | /* Unrolled loop */ |
| 176 | /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ |
| 177 | LTP_pred_Q13 = 2; |
| 178 | LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ 0 ], B_Q14[ 0 ] ); |
| 179 | LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -1 ], B_Q14[ 1 ] ); |
| 180 | LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -2 ], B_Q14[ 2 ] ); |
| 181 | LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -3 ], B_Q14[ 3 ] ); |
| 182 | LTP_pred_Q13 = silk_SMLAWB( LTP_pred_Q13, pred_lag_ptr[ -4 ], B_Q14[ 4 ] ); |
| 183 | pred_lag_ptr++; |
| 184 | |
| 185 | /* Generate LPC excitation */ |
| 186 | pres_Q14[ i ] = silk_ADD_LSHIFT32( pexc_Q14[ i ], LTP_pred_Q13, 1 ); |
| 187 | |
| 188 | /* Update states */ |
| 189 | sLTP_Q15[ sLTP_buf_idx ] = silk_LSHIFT( pres_Q14[ i ], 1 ); |
| 190 | sLTP_buf_idx++; |
| 191 | } |
| 192 | } else { |
| 193 | pres_Q14 = pexc_Q14; |
| 194 | } |
| 195 | |
| 196 | for( i = 0; i < psDec->subfr_length; i++ ) { |
| 197 | /* Short-term prediction */ |
| 198 | silk_assert( psDec->LPC_order == 10 || psDec->LPC_order == 16 ); |
| 199 | /* Avoids introducing a bias because silk_SMLAWB() always rounds to -inf */ |
| 200 | LPC_pred_Q10 = silk_RSHIFT( psDec->LPC_order, 1 ); |
| 201 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 1 ], A_Q12_tmp[ 0 ] ); |
| 202 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 2 ], A_Q12_tmp[ 1 ] ); |
| 203 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 3 ], A_Q12_tmp[ 2 ] ); |
| 204 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 4 ], A_Q12_tmp[ 3 ] ); |
| 205 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 5 ], A_Q12_tmp[ 4 ] ); |
| 206 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 6 ], A_Q12_tmp[ 5 ] ); |
| 207 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 7 ], A_Q12_tmp[ 6 ] ); |
| 208 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 8 ], A_Q12_tmp[ 7 ] ); |
| 209 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 9 ], A_Q12_tmp[ 8 ] ); |
| 210 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 10 ], A_Q12_tmp[ 9 ] ); |
| 211 | if( psDec->LPC_order == 16 ) { |
| 212 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 11 ], A_Q12_tmp[ 10 ] ); |
| 213 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 12 ], A_Q12_tmp[ 11 ] ); |
| 214 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 13 ], A_Q12_tmp[ 12 ] ); |
| 215 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 14 ], A_Q12_tmp[ 13 ] ); |
| 216 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 15 ], A_Q12_tmp[ 14 ] ); |
| 217 | LPC_pred_Q10 = silk_SMLAWB( LPC_pred_Q10, sLPC_Q14[ MAX_LPC_ORDER + i - 16 ], A_Q12_tmp[ 15 ] ); |
| 218 | } |
| 219 | |
| 220 | /* Add prediction to LPC excitation */ |
| 221 | sLPC_Q14[ MAX_LPC_ORDER + i ] = silk_ADD_LSHIFT32( pres_Q14[ i ], LPC_pred_Q10, 4 ); |
| 222 | |
| 223 | /* Scale with gain */ |
| 224 | pxq[ i ] = (opus_int16)silk_SAT16( silk_RSHIFT_ROUND( silk_SMULWW( sLPC_Q14[ MAX_LPC_ORDER + i ], Gain_Q10 ), 8 ) ); |
| 225 | } |
| 226 | |
| 227 | /* DEBUG_STORE_DATA( dec.pcm, pxq, psDec->subfr_length * sizeof( opus_int16 ) ) */ |
| 228 | |
| 229 | /* Update LPC filter state */ |
| 230 | silk_memcpy( sLPC_Q14, &sLPC_Q14[ psDec->subfr_length ], MAX_LPC_ORDER * sizeof( opus_int32 ) ); |
| 231 | pexc_Q14 += psDec->subfr_length; |
| 232 | pxq += psDec->subfr_length; |
| 233 | } |
| 234 | |
| 235 | /* Save LPC state */ |
| 236 | silk_memcpy( psDec->sLPC_Q14_buf, sLPC_Q14, MAX_LPC_ORDER * sizeof( opus_int32 ) ); |
| 237 | RESTORE_STACK; |
| 238 | } |