1 /* 2 * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 /****************************************************************** 12 13 iLBC Speech Coder ANSI-C Source Code 14 15 WebRtcIlbcfix_Decode.c 16 17 ******************************************************************/ 18 19 #include "defines.h" 20 #include "simple_lsf_dequant.h" 21 #include "decoder_interpolate_lsf.h" 22 #include "index_conv_dec.h" 23 #include "do_plc.h" 24 #include "constants.h" 25 #include "enhancer_interface.h" 26 #include "xcorr_coef.h" 27 #include "lsf_check.h" 28 #include "decode_residual.h" 29 #include "unpack_bits.h" 30 #include "hp_output.h" 31 #ifndef WEBRTC_ARCH_BIG_ENDIAN 32 #include "swap_bytes.h" 33 #endif 34 35 /*----------------------------------------------------------------* 36 * main decoder function 37 *---------------------------------------------------------------*/ 38 39 void WebRtcIlbcfix_DecodeImpl( 40 int16_t *decblock, /* (o) decoded signal block */ 41 const uint16_t *bytes, /* (i) encoded signal bits */ 42 iLBC_Dec_Inst_t *iLBCdec_inst, /* (i/o) the decoder state 43 structure */ 44 int16_t mode /* (i) 0: bad packet, PLC, 45 1: normal */ 46 ) { 47 int i; 48 int16_t order_plus_one; 49 50 int16_t last_bit; 51 int16_t *data; 52 /* Stack based */ 53 int16_t decresidual[BLOCKL_MAX]; 54 int16_t PLCresidual[BLOCKL_MAX + LPC_FILTERORDER]; 55 int16_t syntdenum[NSUB_MAX*(LPC_FILTERORDER+1)]; 56 int16_t PLClpc[LPC_FILTERORDER + 1]; 57 #ifndef WEBRTC_ARCH_BIG_ENDIAN 58 uint16_t swapped[NO_OF_WORDS_30MS]; 59 #endif 60 iLBC_bits *iLBCbits_inst = (iLBC_bits*)PLCresidual; 61 62 /* Reuse some buffers that are non overlapping in order to save stack memory */ 63 data = &PLCresidual[LPC_FILTERORDER]; 64 65 if (mode) { /* the data are good */ 66 67 /* decode data */ 68 69 /* Unpacketize bits into parameters */ 70 71 #ifndef WEBRTC_ARCH_BIG_ENDIAN 72 WebRtcIlbcfix_SwapBytes(bytes, iLBCdec_inst->no_of_words, swapped); 73 last_bit = WebRtcIlbcfix_UnpackBits(swapped, iLBCbits_inst, iLBCdec_inst->mode); 74 #else 75 last_bit = WebRtcIlbcfix_UnpackBits(bytes, iLBCbits_inst, iLBCdec_inst->mode); 76 #endif 77 78 /* Check for bit errors */ 79 if (iLBCbits_inst->startIdx<1) 80 mode = 0; 81 if ((iLBCdec_inst->mode==20) && (iLBCbits_inst->startIdx>3)) 82 mode = 0; 83 if ((iLBCdec_inst->mode==30) && (iLBCbits_inst->startIdx>5)) 84 mode = 0; 85 if (last_bit==1) 86 mode = 0; 87 88 if (mode) { /* No bit errors was detected, continue decoding */ 89 /* Stack based */ 90 int16_t lsfdeq[LPC_FILTERORDER*LPC_N_MAX]; 91 int16_t weightdenum[(LPC_FILTERORDER + 1)*NSUB_MAX]; 92 93 /* adjust index */ 94 WebRtcIlbcfix_IndexConvDec(iLBCbits_inst->cb_index); 95 96 /* decode the lsf */ 97 WebRtcIlbcfix_SimpleLsfDeQ(lsfdeq, (int16_t*)(iLBCbits_inst->lsf), iLBCdec_inst->lpc_n); 98 WebRtcIlbcfix_LsfCheck(lsfdeq, LPC_FILTERORDER, iLBCdec_inst->lpc_n); 99 WebRtcIlbcfix_DecoderInterpolateLsp(syntdenum, weightdenum, 100 lsfdeq, LPC_FILTERORDER, iLBCdec_inst); 101 102 /* Decode the residual using the cb and gain indexes */ 103 WebRtcIlbcfix_DecodeResidual(iLBCdec_inst, iLBCbits_inst, decresidual, syntdenum); 104 105 /* preparing the plc for a future loss! */ 106 WebRtcIlbcfix_DoThePlc( PLCresidual, PLClpc, 0, 107 decresidual, syntdenum + (LPC_FILTERORDER + 1)*(iLBCdec_inst->nsub - 1), 108 (int16_t)(iLBCdec_inst->last_lag), iLBCdec_inst); 109 110 /* Use the output from doThePLC */ 111 WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl); 112 } 113 114 } 115 116 if (mode == 0) { 117 /* the data is bad (either a PLC call 118 * was made or a bit error was detected) 119 */ 120 121 /* packet loss conceal */ 122 123 WebRtcIlbcfix_DoThePlc( PLCresidual, PLClpc, 1, 124 decresidual, syntdenum, (int16_t)(iLBCdec_inst->last_lag), iLBCdec_inst); 125 126 WEBRTC_SPL_MEMCPY_W16(decresidual, PLCresidual, iLBCdec_inst->blockl); 127 128 order_plus_one = LPC_FILTERORDER + 1; 129 130 for (i = 0; i < iLBCdec_inst->nsub; i++) { 131 WEBRTC_SPL_MEMCPY_W16(syntdenum+(i*order_plus_one), 132 PLClpc, order_plus_one); 133 } 134 } 135 136 if ((*iLBCdec_inst).use_enhancer == 1) { /* Enhancer activated */ 137 138 /* Update the filter and filter coefficients if there was a packet loss */ 139 if (iLBCdec_inst->prev_enh_pl==2) { 140 for (i=0;i<iLBCdec_inst->nsub;i++) { 141 WEBRTC_SPL_MEMCPY_W16(&(iLBCdec_inst->old_syntdenum[i*(LPC_FILTERORDER+1)]), 142 syntdenum, (LPC_FILTERORDER+1)); 143 } 144 } 145 146 /* post filtering */ 147 (*iLBCdec_inst).last_lag = 148 WebRtcIlbcfix_EnhancerInterface(data, decresidual, iLBCdec_inst); 149 150 /* synthesis filtering */ 151 152 /* Set up the filter state */ 153 WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER); 154 155 if (iLBCdec_inst->mode==20) { 156 /* Enhancer has 40 samples delay */ 157 i=0; 158 WebRtcSpl_FilterARFastQ12( 159 data, data, 160 iLBCdec_inst->old_syntdenum + (i+iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1), 161 LPC_FILTERORDER+1, SUBL); 162 163 for (i=1; i < iLBCdec_inst->nsub; i++) { 164 WebRtcSpl_FilterARFastQ12( 165 data+i*SUBL, data+i*SUBL, 166 syntdenum+(i-1)*(LPC_FILTERORDER+1), 167 LPC_FILTERORDER+1, SUBL); 168 } 169 170 } else if (iLBCdec_inst->mode==30) { 171 /* Enhancer has 80 samples delay */ 172 for (i=0; i < 2; i++) { 173 WebRtcSpl_FilterARFastQ12( 174 data+i*SUBL, data+i*SUBL, 175 iLBCdec_inst->old_syntdenum + (i+4)*(LPC_FILTERORDER+1), 176 LPC_FILTERORDER+1, SUBL); 177 } 178 for (i=2; i < iLBCdec_inst->nsub; i++) { 179 WebRtcSpl_FilterARFastQ12( 180 data+i*SUBL, data+i*SUBL, 181 syntdenum+(i-2)*(LPC_FILTERORDER+1), 182 LPC_FILTERORDER+1, SUBL); 183 } 184 } 185 186 /* Save the filter state */ 187 WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER); 188 189 } else { /* Enhancer not activated */ 190 int16_t lag; 191 192 /* Find last lag (since the enhancer is not called to give this info) */ 193 lag = 20; 194 if (iLBCdec_inst->mode==20) { 195 lag = (int16_t)WebRtcIlbcfix_XcorrCoef( 196 &decresidual[iLBCdec_inst->blockl-60], 197 &decresidual[iLBCdec_inst->blockl-60-lag], 198 60, 199 80, lag, -1); 200 } else { 201 lag = (int16_t)WebRtcIlbcfix_XcorrCoef( 202 &decresidual[iLBCdec_inst->blockl-ENH_BLOCKL], 203 &decresidual[iLBCdec_inst->blockl-ENH_BLOCKL-lag], 204 ENH_BLOCKL, 205 100, lag, -1); 206 } 207 208 /* Store lag (it is needed if next packet is lost) */ 209 (*iLBCdec_inst).last_lag = (int)lag; 210 211 /* copy data and run synthesis filter */ 212 WEBRTC_SPL_MEMCPY_W16(data, decresidual, iLBCdec_inst->blockl); 213 214 /* Set up the filter state */ 215 WEBRTC_SPL_MEMCPY_W16(&data[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER); 216 217 for (i=0; i < iLBCdec_inst->nsub; i++) { 218 WebRtcSpl_FilterARFastQ12( 219 data+i*SUBL, data+i*SUBL, 220 syntdenum + i*(LPC_FILTERORDER+1), 221 LPC_FILTERORDER+1, SUBL); 222 } 223 224 /* Save the filter state */ 225 WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &data[iLBCdec_inst->blockl-LPC_FILTERORDER], LPC_FILTERORDER); 226 } 227 228 WEBRTC_SPL_MEMCPY_W16(decblock,data,iLBCdec_inst->blockl); 229 230 /* High pass filter the signal (with upscaling a factor 2 and saturation) */ 231 WebRtcIlbcfix_HpOutput(decblock, (int16_t*)WebRtcIlbcfix_kHpOutCoefs, 232 iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx, 233 iLBCdec_inst->blockl); 234 235 WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->old_syntdenum, 236 syntdenum, iLBCdec_inst->nsub*(LPC_FILTERORDER+1)); 237 238 iLBCdec_inst->prev_enh_pl=0; 239 240 if (mode==0) { /* PLC was used */ 241 iLBCdec_inst->prev_enh_pl=1; 242 } 243 } 244
