mirror of
https://github.com/oxen-io/session-android.git
synced 2024-12-19 06:27:30 +00:00
120 lines
4.1 KiB
C
120 lines
4.1 KiB
C
/*
|
|
* 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_StateSearch.c
|
|
|
|
******************************************************************/
|
|
|
|
#include "defines.h"
|
|
#include "constants.h"
|
|
#include "abs_quant.h"
|
|
|
|
/*----------------------------------------------------------------*
|
|
* encoding of start state
|
|
*---------------------------------------------------------------*/
|
|
|
|
void WebRtcIlbcfix_StateSearch(
|
|
iLBC_Enc_Inst_t *iLBCenc_inst,
|
|
/* (i) Encoder instance */
|
|
iLBC_bits *iLBC_encbits,/* (i/o) Encoded bits (output idxForMax
|
|
and idxVec, input state_first) */
|
|
int16_t *residual, /* (i) target residual vector */
|
|
int16_t *syntDenum, /* (i) lpc synthesis filter */
|
|
int16_t *weightDenum /* (i) weighting filter denuminator */
|
|
) {
|
|
int16_t k, index;
|
|
int16_t maxVal;
|
|
int16_t scale, shift;
|
|
int32_t maxValsq;
|
|
int16_t scaleRes;
|
|
int16_t max;
|
|
int i;
|
|
/* Stack based */
|
|
int16_t numerator[1+LPC_FILTERORDER];
|
|
int16_t residualLongVec[2*STATE_SHORT_LEN_30MS+LPC_FILTERORDER];
|
|
int16_t sampleMa[2*STATE_SHORT_LEN_30MS];
|
|
int16_t *residualLong = &residualLongVec[LPC_FILTERORDER];
|
|
int16_t *sampleAr = residualLong;
|
|
|
|
/* Scale to maximum 12 bits to avoid saturation in circular convolution filter */
|
|
max = WebRtcSpl_MaxAbsValueW16(residual, iLBCenc_inst->state_short_len);
|
|
scaleRes = WebRtcSpl_GetSizeInBits(max)-12;
|
|
scaleRes = WEBRTC_SPL_MAX(0, scaleRes);
|
|
/* Set up the filter coefficients for the circular convolution */
|
|
for (i=0; i<LPC_FILTERORDER+1; i++) {
|
|
numerator[i] = (syntDenum[LPC_FILTERORDER-i]>>scaleRes);
|
|
}
|
|
|
|
/* Copy the residual to a temporary buffer that we can filter
|
|
* and set the remaining samples to zero.
|
|
*/
|
|
WEBRTC_SPL_MEMCPY_W16(residualLong, residual, iLBCenc_inst->state_short_len);
|
|
WebRtcSpl_MemSetW16(residualLong + iLBCenc_inst->state_short_len, 0, iLBCenc_inst->state_short_len);
|
|
|
|
/* Run the Zero-Pole filter (Ciurcular convolution) */
|
|
WebRtcSpl_MemSetW16(residualLongVec, 0, LPC_FILTERORDER);
|
|
WebRtcSpl_FilterMAFastQ12(
|
|
residualLong, sampleMa,
|
|
numerator, LPC_FILTERORDER+1, (int16_t)(iLBCenc_inst->state_short_len + LPC_FILTERORDER));
|
|
WebRtcSpl_MemSetW16(&sampleMa[iLBCenc_inst->state_short_len + LPC_FILTERORDER], 0, iLBCenc_inst->state_short_len - LPC_FILTERORDER);
|
|
|
|
WebRtcSpl_FilterARFastQ12(
|
|
sampleMa, sampleAr,
|
|
syntDenum, LPC_FILTERORDER+1, (int16_t)(2*iLBCenc_inst->state_short_len));
|
|
|
|
for(k=0;k<iLBCenc_inst->state_short_len;k++){
|
|
sampleAr[k] += sampleAr[k+iLBCenc_inst->state_short_len];
|
|
}
|
|
|
|
/* Find maximum absolute value in the vector */
|
|
maxVal=WebRtcSpl_MaxAbsValueW16(sampleAr, iLBCenc_inst->state_short_len);
|
|
|
|
/* Find the best index */
|
|
|
|
if ((((int32_t)maxVal)<<scaleRes)<23170) {
|
|
maxValsq=((int32_t)maxVal*maxVal)<<(2+2*scaleRes);
|
|
} else {
|
|
maxValsq=(int32_t)WEBRTC_SPL_WORD32_MAX;
|
|
}
|
|
|
|
index=0;
|
|
for (i=0;i<63;i++) {
|
|
|
|
if (maxValsq>=WebRtcIlbcfix_kChooseFrgQuant[i]) {
|
|
index=i+1;
|
|
} else {
|
|
i=63;
|
|
}
|
|
}
|
|
iLBC_encbits->idxForMax=index;
|
|
|
|
/* Rescale the vector before quantization */
|
|
scale=WebRtcIlbcfix_kScale[index];
|
|
|
|
if (index<27) { /* scale table is in Q16, fout[] is in Q(-1) and we want the result to be in Q11 */
|
|
shift=4;
|
|
} else { /* scale table is in Q21, fout[] is in Q(-1) and we want the result to be in Q11 */
|
|
shift=9;
|
|
}
|
|
|
|
/* Set up vectors for AbsQuant and rescale it with the scale factor */
|
|
WebRtcSpl_ScaleVectorWithSat(sampleAr, sampleAr, scale,
|
|
iLBCenc_inst->state_short_len, (int16_t)(shift-scaleRes));
|
|
|
|
/* Quantize the values in fout[] */
|
|
WebRtcIlbcfix_AbsQuant(iLBCenc_inst, iLBC_encbits, sampleAr, weightDenum);
|
|
|
|
return;
|
|
}
|