1 /* 2 * Copyright (c) 2011 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_StateConstruct.c 16 17 ******************************************************************/ 18 19 #include "defines.h" 20 #include "constants.h" 21 22 /*----------------------------------------------------------------* 23 * decoding of the start state 24 *---------------------------------------------------------------*/ 25 26 void WebRtcIlbcfix_StateConstruct( 27 int16_t idxForMax, /* (i) 6-bit index for the quantization of 28 max amplitude */ 29 int16_t *idxVec, /* (i) vector of quantization indexes */ 30 int16_t *syntDenum, /* (i) synthesis filter denumerator */ 31 int16_t *Out_fix, /* (o) the decoded state vector */ 32 int16_t len /* (i) length of a state vector */ 33 ) { 34 int k; 35 int16_t maxVal; 36 int16_t *tmp1, *tmp2, *tmp3; 37 /* Stack based */ 38 int16_t numerator[1+LPC_FILTERORDER]; 39 int16_t sampleValVec[2*STATE_SHORT_LEN_30MS+LPC_FILTERORDER]; 40 int16_t sampleMaVec[2*STATE_SHORT_LEN_30MS+LPC_FILTERORDER]; 41 int16_t *sampleVal = &sampleValVec[LPC_FILTERORDER]; 42 int16_t *sampleMa = &sampleMaVec[LPC_FILTERORDER]; 43 int16_t *sampleAr = &sampleValVec[LPC_FILTERORDER]; 44 45 /* initialization of coefficients */ 46 47 for (k=0; k<LPC_FILTERORDER+1; k++){ 48 numerator[k] = syntDenum[LPC_FILTERORDER-k]; 49 } 50 51 /* decoding of the maximum value */ 52 53 maxVal = WebRtcIlbcfix_kFrgQuantMod[idxForMax]; 54 55 /* decoding of the sample values */ 56 tmp1 = sampleVal; 57 tmp2 = &idxVec[len-1]; 58 59 if (idxForMax<37) { 60 for(k=0; k<len; k++){ 61 /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 2097152 (= 0.5 << 22) 62 maxVal is in Q8 and result is in Q(-1) */ 63 (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)2097152) >> 22); 64 tmp1++; 65 tmp2--; 66 } 67 } else if (idxForMax<59) { 68 for(k=0; k<len; k++){ 69 /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 262144 (= 0.5 << 19) 70 maxVal is in Q5 and result is in Q(-1) */ 71 (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)262144) >> 19); 72 tmp1++; 73 tmp2--; 74 } 75 } else { 76 for(k=0; k<len; k++){ 77 /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 65536 (= 0.5 << 17) 78 maxVal is in Q3 and result is in Q(-1) */ 79 (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)65536) >> 17); 80 tmp1++; 81 tmp2--; 82 } 83 } 84 85 /* Set the rest of the data to zero */ 86 WebRtcSpl_MemSetW16(&sampleVal[len], 0, len); 87 88 /* circular convolution with all-pass filter */ 89 90 /* Set the state to zero */ 91 WebRtcSpl_MemSetW16(sampleValVec, 0, (LPC_FILTERORDER)); 92 93 /* Run MA filter + AR filter */ 94 WebRtcSpl_FilterMAFastQ12( 95 sampleVal, sampleMa, 96 numerator, LPC_FILTERORDER+1, (int16_t)(len + LPC_FILTERORDER)); 97 WebRtcSpl_MemSetW16(&sampleMa[len + LPC_FILTERORDER], 0, (len - LPC_FILTERORDER)); 98 WebRtcSpl_FilterARFastQ12( 99 sampleMa, sampleAr, 100 syntDenum, LPC_FILTERORDER+1, (int16_t)(2*len)); 101 102 tmp1 = &sampleAr[len-1]; 103 tmp2 = &sampleAr[2*len-1]; 104 tmp3 = Out_fix; 105 for(k=0;k<len;k++){ 106 (*tmp3) = (*tmp1) + (*tmp2); 107 tmp1--; 108 tmp2--; 109 tmp3++; 110 } 111 } 112
