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git-svn-id: http://webrtc.googlecode.com/svn/trunk@4 4adac7df-926f-26a2-2b94-8c16560cd09d

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niklase@google.com
2011-05-30 11:22:19 +00:00
parent 01813fe945
commit 77ae29bc81
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modules/audio_coding/codecs/iLBC/main/source/enhancer_interface.c Normal file
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/*
* 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_EnhancerInterface.c
******************************************************************/
#include "defines.h"
#include "constants.h"
#include "xcorr_coef.h"
#include "enhancer.h"
#include "hp_output.h"
/*----------------------------------------------------------------*
* interface for enhancer
*---------------------------------------------------------------*/
int WebRtcIlbcfix_EnhancerInterface( /* (o) Estimated lag in end of in[] */
WebRtc_Word16 *out, /* (o) enhanced signal */
WebRtc_Word16 *in, /* (i) unenhanced signal */
iLBC_Dec_Inst_t *iLBCdec_inst /* (i) buffers etc */
){
int iblock;
int lag=20, tlag=20;
int inLen=iLBCdec_inst->blockl+120;
WebRtc_Word16 scale, scale1, plc_blockl;
WebRtc_Word16 *enh_buf, *enh_period;
WebRtc_Word32 tmp1, tmp2, max, new_blocks;
WebRtc_Word16 *enh_bufPtr1;
int i, k;
WebRtc_Word16 EnChange;
WebRtc_Word16 SqrtEnChange;
WebRtc_Word16 inc;
WebRtc_Word16 win;
WebRtc_Word16 *tmpW16ptr;
WebRtc_Word16 startPos;
WebRtc_Word16 *plc_pred;
WebRtc_Word16 *target, *regressor;
WebRtc_Word16 max16;
int shifts;
WebRtc_Word32 ener;
WebRtc_Word16 enerSh;
WebRtc_Word16 corrSh;
WebRtc_Word16 ind, sh;
WebRtc_Word16 start, stop;
/* Stack based */
WebRtc_Word16 totsh[3];
WebRtc_Word16 downsampled[(BLOCKL_MAX+120)>>1]; /* length 180 */
WebRtc_Word32 corr32[50];
WebRtc_Word32 corrmax[3];
WebRtc_Word16 corr16[3];
WebRtc_Word16 en16[3];
WebRtc_Word16 lagmax[3];
plc_pred = downsampled; /* Reuse memory since plc_pred[ENH_BLOCKL] and downsampled are non overlapping */
enh_buf=iLBCdec_inst->enh_buf;
enh_period=iLBCdec_inst->enh_period;
/* Copy in the new data into the enhancer buffer */
WEBRTC_SPL_MEMMOVE_W16(enh_buf, &enh_buf[iLBCdec_inst->blockl],
ENH_BUFL-iLBCdec_inst->blockl);
WEBRTC_SPL_MEMCPY_W16(&enh_buf[ENH_BUFL-iLBCdec_inst->blockl], in,
iLBCdec_inst->blockl);
/* Set variables that are dependent on frame size */
if (iLBCdec_inst->mode==30) {
plc_blockl=ENH_BLOCKL;
new_blocks=3;
startPos=320; /* Start position for enhancement (640-new_blocks*ENH_BLOCKL-80) */
} else {
plc_blockl=40;
new_blocks=2;
startPos=440; /* Start position for enhancement (640-new_blocks*ENH_BLOCKL-40) */
}
/* Update the pitch prediction for each enhancer block, move the old ones */
WEBRTC_SPL_MEMMOVE_W16(enh_period, &enh_period[new_blocks], (ENH_NBLOCKS_TOT-new_blocks));
k=WebRtcSpl_DownsampleFast(
enh_buf+ENH_BUFL-inLen, /* Input samples */
(WebRtc_Word16)(inLen+ENH_BUFL_FILTEROVERHEAD),
downsampled,
(WebRtc_Word16)WEBRTC_SPL_RSHIFT_W16(inLen, 1),
(WebRtc_Word16*)WebRtcIlbcfix_kLpFiltCoefs, /* Coefficients in Q12 */
FILTERORDER_DS_PLUS1, /* Length of filter (order-1) */
FACTOR_DS,
DELAY_DS);
/* Estimate the pitch in the down sampled domain. */
for(iblock = 0; iblock<new_blocks; iblock++){
/* references */
i=60+WEBRTC_SPL_MUL_16_16(iblock,ENH_BLOCKL_HALF);
target=downsampled+i;
regressor=downsampled+i-10;
/* scaling */
max16=WebRtcSpl_MaxAbsValueW16(&regressor[-50], (WebRtc_Word16)(ENH_BLOCKL_HALF+50-1));
shifts = WebRtcSpl_GetSizeInBits(WEBRTC_SPL_MUL_16_16(max16, max16)) - 25;
shifts = WEBRTC_SPL_MAX(0, shifts);
/* compute cross correlation */
WebRtcSpl_CrossCorrelation(corr32, target, regressor,
ENH_BLOCKL_HALF, 50, (WebRtc_Word16)shifts, -1);
/* Find 3 highest correlations that should be compared for the
highest (corr*corr)/ener */
for (i=0;i<2;i++) {
lagmax[i] = WebRtcSpl_MaxIndexW32(corr32, 50);
corrmax[i] = corr32[lagmax[i]];
start = lagmax[i] - 2;
stop = lagmax[i] + 2;
start = WEBRTC_SPL_MAX(0, start);
stop = WEBRTC_SPL_MIN(49, stop);
for (k=start; k<=stop; k++) {
corr32[k] = 0;
}
}
lagmax[2] = WebRtcSpl_MaxIndexW32(corr32, 50);
corrmax[2] = corr32[lagmax[2]];
/* Calculate normalized corr^2 and ener */
for (i=0;i<3;i++) {
corrSh = 15-WebRtcSpl_GetSizeInBits(corrmax[i]);
ener = WebRtcSpl_DotProductWithScale(&regressor[-lagmax[i]], &regressor[-lagmax[i]], ENH_BLOCKL_HALF, shifts);
enerSh = 15-WebRtcSpl_GetSizeInBits(ener);
corr16[i] = (WebRtc_Word16)WEBRTC_SPL_SHIFT_W32(corrmax[i], corrSh);
corr16[i] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(corr16[i], corr16[i], 16);
en16[i] = (WebRtc_Word16)WEBRTC_SPL_SHIFT_W32(ener, enerSh);
totsh[i] = enerSh - WEBRTC_SPL_LSHIFT_W32(corrSh, 1);
}
/* Compare lagmax[0..3] for the (corr^2)/ener criteria */
ind = 0;
for (i=1; i<3; i++) {
if (totsh[ind] > totsh[i]) {
sh = WEBRTC_SPL_MIN(31, totsh[ind]-totsh[i]);
if ( WEBRTC_SPL_MUL_16_16(corr16[ind], en16[i]) < WEBRTC_SPL_MUL_16_16_RSFT(corr16[i], en16[ind], sh)) {
ind = i;
}
} else {
sh = WEBRTC_SPL_MIN(31, totsh[i]-totsh[ind]);
if (WEBRTC_SPL_MUL_16_16_RSFT(corr16[ind], en16[i], sh) < WEBRTC_SPL_MUL_16_16(corr16[i], en16[ind])) {
ind = i;
}
}
}
lag = lagmax[ind] + 10;
/* Store the estimated lag in the non-downsampled domain */
enh_period[ENH_NBLOCKS_TOT-new_blocks+iblock] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16(lag, 8);
/* Store the estimated lag for backward PLC */
if (iLBCdec_inst->prev_enh_pl==1) {
if (!iblock) {
tlag = WEBRTC_SPL_MUL_16_16(lag, 2);
}
} else {
if (iblock==1) {
tlag = WEBRTC_SPL_MUL_16_16(lag, 2);
}
}
lag = WEBRTC_SPL_MUL_16_16(lag, 2);
}
if ((iLBCdec_inst->prev_enh_pl==1)||(iLBCdec_inst->prev_enh_pl==2)) {
/* Calculate the best lag of the new frame
This is used to interpolate backwards and mix with the PLC'd data
*/
/* references */
target=in;
regressor=in+tlag-1;
/* scaling */
max16=WebRtcSpl_MaxAbsValueW16(regressor, (WebRtc_Word16)(plc_blockl+3-1));
if (max16>5000)
shifts=2;
else
shifts=0;
/* compute cross correlation */
WebRtcSpl_CrossCorrelation(corr32, target, regressor,
plc_blockl, 3, (WebRtc_Word16)shifts, 1);
/* find lag */
lag=WebRtcSpl_MaxIndexW32(corr32, 3);
lag+=tlag-1;
/* Copy the backward PLC to plc_pred */
if (iLBCdec_inst->prev_enh_pl==1) {
if (lag>plc_blockl) {
WEBRTC_SPL_MEMCPY_W16(plc_pred, &in[lag-plc_blockl], plc_blockl);
} else {
WEBRTC_SPL_MEMCPY_W16(&plc_pred[plc_blockl-lag], in, lag);
WEBRTC_SPL_MEMCPY_W16(plc_pred, &enh_buf[ENH_BUFL-iLBCdec_inst->blockl-plc_blockl+lag], (plc_blockl-lag));
}
} else {
int pos;
pos = plc_blockl;
while (lag<pos) {
WEBRTC_SPL_MEMCPY_W16(&plc_pred[pos-lag], in, lag);
pos = pos - lag;
}
WEBRTC_SPL_MEMCPY_W16(plc_pred, &in[lag-pos], pos);
}
if (iLBCdec_inst->prev_enh_pl==1) {
/* limit energy change
if energy in backward PLC is more than 4 times higher than the forward PLC,
then reduce the energy in the backward PLC vector:
sample 1...len-16 set energy of the to 4 times forward PLC
sample len-15..len interpolate between 4 times fw PLC and bw PLC energy
Note: Compared to floating point code there is a slight change,
the window is 16 samples long instead of 10 samples to simplify the calculations
*/
max=WebRtcSpl_MaxAbsValueW16(&enh_buf[ENH_BUFL-iLBCdec_inst->blockl-plc_blockl], plc_blockl);
max16=WebRtcSpl_MaxAbsValueW16(plc_pred, plc_blockl);
max = WEBRTC_SPL_MAX(max, max16);
scale=22-(WebRtc_Word16)WebRtcSpl_NormW32(max);
scale=WEBRTC_SPL_MAX(scale,0);
tmp2 = WebRtcSpl_DotProductWithScale(&enh_buf[ENH_BUFL-iLBCdec_inst->blockl-plc_blockl], &enh_buf[ENH_BUFL-iLBCdec_inst->blockl-plc_blockl], plc_blockl, scale);
tmp1 = WebRtcSpl_DotProductWithScale(plc_pred, plc_pred, plc_blockl, scale);
/* Check the energy difference */
if ((tmp1>0)&&((tmp1>>2)>tmp2)) {
/* EnChange is now guaranteed to be <0.5
Calculate EnChange=tmp2/tmp1 in Q16
*/
scale1=(WebRtc_Word16)WebRtcSpl_NormW32(tmp1);
tmp1=WEBRTC_SPL_SHIFT_W32(tmp1, (scale1-16)); /* using 15 bits */
tmp2=WEBRTC_SPL_SHIFT_W32(tmp2, (scale1));
EnChange = (WebRtc_Word16)WebRtcSpl_DivW32W16(tmp2, (WebRtc_Word16)tmp1);
/* Calculate the Sqrt of the energy in Q15 ((14+16)/2) */
SqrtEnChange = (WebRtc_Word16)WebRtcSpl_Sqrt(WEBRTC_SPL_LSHIFT_W32((WebRtc_Word32)EnChange, 14));
/* Multiply first part of vector with 2*SqrtEnChange */
WebRtcSpl_ScaleVector(plc_pred, plc_pred, SqrtEnChange, (WebRtc_Word16)(plc_blockl-16), 14);
/* Calculate increase parameter for window part (16 last samples) */
inc=(2048-WEBRTC_SPL_RSHIFT_W16(SqrtEnChange, 3)); /* (1-2*SqrtEnChange)/16 in Q15 */
win=0;
tmpW16ptr=&plc_pred[plc_blockl-16];
for (i=16;i>0;i--) {
(*tmpW16ptr)=(WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT((*tmpW16ptr),
(SqrtEnChange+(win>>1)), 14); /* multiply by (2.0*SqrtEnChange+win) */
win += inc;
tmpW16ptr++;
}
}
/* Make the linear interpolation between the forward PLC'd data
and the backward PLC'd data (from the new frame)
*/
if (plc_blockl==40) {
inc=400; /* 1/41 in Q14 */
} else { /* plc_blockl==80 */
inc=202; /* 1/81 in Q14 */
}
win=0;
enh_bufPtr1=&enh_buf[ENH_BUFL-1-iLBCdec_inst->blockl];
for (i=0; i<plc_blockl; i++) {
win+=inc;
*enh_bufPtr1 = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT((*enh_bufPtr1), win, 14);
*enh_bufPtr1 += (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT((16384-win), plc_pred[plc_blockl-1-i], 14);
enh_bufPtr1--;
}
} else {
WebRtc_Word16 *synt = &downsampled[LPC_FILTERORDER];
enh_bufPtr1=&enh_buf[ENH_BUFL-iLBCdec_inst->blockl-plc_blockl];
WEBRTC_SPL_MEMCPY_W16(enh_bufPtr1, plc_pred, plc_blockl);
/* Clear fileter memory */
WebRtcSpl_MemSetW16(iLBCdec_inst->syntMem, 0, LPC_FILTERORDER);
WebRtcSpl_MemSetW16(iLBCdec_inst->hpimemy, 0, 4);
WebRtcSpl_MemSetW16(iLBCdec_inst->hpimemx, 0, 2);
/* Initialize filter memory by filtering through 2 lags */
WEBRTC_SPL_MEMCPY_W16(&synt[-LPC_FILTERORDER], iLBCdec_inst->syntMem, LPC_FILTERORDER);
WebRtcSpl_FilterARFastQ12(
enh_bufPtr1, synt,
&iLBCdec_inst->old_syntdenum[(iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1)], LPC_FILTERORDER+1, (WebRtc_Word16)lag);
WEBRTC_SPL_MEMCPY_W16(&synt[-LPC_FILTERORDER], &synt[lag-LPC_FILTERORDER], LPC_FILTERORDER);
WebRtcIlbcfix_HpOutput(synt, (WebRtc_Word16*)WebRtcIlbcfix_kHpOutCoefs,
iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx,
(WebRtc_Word16)lag);
WebRtcSpl_FilterARFastQ12(
enh_bufPtr1, synt,
&iLBCdec_inst->old_syntdenum[(iLBCdec_inst->nsub-1)*(LPC_FILTERORDER+1)], LPC_FILTERORDER+1, (WebRtc_Word16)lag);
WEBRTC_SPL_MEMCPY_W16(iLBCdec_inst->syntMem, &synt[lag-LPC_FILTERORDER], LPC_FILTERORDER);
WebRtcIlbcfix_HpOutput(synt, (WebRtc_Word16*)WebRtcIlbcfix_kHpOutCoefs,
iLBCdec_inst->hpimemy, iLBCdec_inst->hpimemx,
(WebRtc_Word16)lag);
}
}
/* Perform enhancement block by block */
for (iblock = 0; iblock<new_blocks; iblock++) {
WebRtcIlbcfix_Enhancer(iLBCdec_inst, out+WEBRTC_SPL_MUL_16_16(iblock, ENH_BLOCKL), enh_buf,
ENH_BUFL, (WebRtc_Word16)(WEBRTC_SPL_MUL_16_16(iblock, ENH_BLOCKL)+startPos),
enh_period, (WebRtc_Word16*)WebRtcIlbcfix_kEnhPlocs, ENH_NBLOCKS_TOT);
}
return (lag);
}