/* * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ /****************************************************************** iLBC Speech Coder ANSI-C Source Code WebRtcIlbcfix_StateConstruct.c ******************************************************************/ #include "defines.h" #include "constants.h" /*----------------------------------------------------------------* * decoding of the start state *---------------------------------------------------------------*/ void WebRtcIlbcfix_StateConstruct( int16_t idxForMax, /* (i) 6-bit index for the quantization of max amplitude */ int16_t *idxVec, /* (i) vector of quantization indexes */ int16_t *syntDenum, /* (i) synthesis filter denumerator */ int16_t *Out_fix, /* (o) the decoded state vector */ int16_t len /* (i) length of a state vector */ ) { int k; int16_t maxVal; int16_t *tmp1, *tmp2, *tmp3; /* Stack based */ int16_t numerator[1+LPC_FILTERORDER]; int16_t sampleValVec[2*STATE_SHORT_LEN_30MS+LPC_FILTERORDER]; int16_t sampleMaVec[2*STATE_SHORT_LEN_30MS+LPC_FILTERORDER]; int16_t *sampleVal = &sampleValVec[LPC_FILTERORDER]; int16_t *sampleMa = &sampleMaVec[LPC_FILTERORDER]; int16_t *sampleAr = &sampleValVec[LPC_FILTERORDER]; /* initialization of coefficients */ for (k=0; k<LPC_FILTERORDER+1; k++){ numerator[k] = syntDenum[LPC_FILTERORDER-k]; } /* decoding of the maximum value */ maxVal = WebRtcIlbcfix_kFrgQuantMod[idxForMax]; /* decoding of the sample values */ tmp1 = sampleVal; tmp2 = &idxVec[len-1]; if (idxForMax<37) { for(k=0; k<len; k++){ /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 2097152 (= 0.5 << 22) maxVal is in Q8 and result is in Q(-1) */ (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)2097152) >> 22); tmp1++; tmp2--; } } else if (idxForMax<59) { for(k=0; k<len; k++){ /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 262144 (= 0.5 << 19) maxVal is in Q5 and result is in Q(-1) */ (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)262144) >> 19); tmp1++; tmp2--; } } else { for(k=0; k<len; k++){ /*the shifting is due to the Q13 in sq4_fixQ13[i], also the adding of 65536 (= 0.5 << 17) maxVal is in Q3 and result is in Q(-1) */ (*tmp1) = (int16_t) ((WEBRTC_SPL_MUL_16_16(maxVal,WebRtcIlbcfix_kStateSq3[(*tmp2)])+(int32_t)65536) >> 17); tmp1++; tmp2--; } } /* Set the rest of the data to zero */ WebRtcSpl_MemSetW16(&sampleVal[len], 0, len); /* circular convolution with all-pass filter */ /* Set the state to zero */ WebRtcSpl_MemSetW16(sampleValVec, 0, (LPC_FILTERORDER)); /* Run MA filter + AR filter */ WebRtcSpl_FilterMAFastQ12( sampleVal, sampleMa, numerator, LPC_FILTERORDER+1, (int16_t)(len + LPC_FILTERORDER)); WebRtcSpl_MemSetW16(&sampleMa[len + LPC_FILTERORDER], 0, (len - LPC_FILTERORDER)); WebRtcSpl_FilterARFastQ12( sampleMa, sampleAr, syntDenum, LPC_FILTERORDER+1, (int16_t)(2*len)); tmp1 = &sampleAr[len-1]; tmp2 = &sampleAr[2*len-1]; tmp3 = Out_fix; for(k=0;k<len;k++){ (*tmp3) = (*tmp1) + (*tmp2); tmp1--; tmp2--; tmp3++; } }