mirror of
https://github.com/oxen-io/session-android.git
synced 2024-12-23 16:37:30 +00:00
89 lines
2.8 KiB
C
89 lines
2.8 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_FrameClassify.c
|
||
|
|
|
||
|
|
******************************************************************/
|
||
|
|
|
||
|
|
#include "defines.h"
|
||
|
|
#include "constants.h"
|
||
|
|
|
||
|
|
/*----------------------------------------------------------------*
|
||
|
|
* Classification of subframes to localize start state
|
||
|
|
*---------------------------------------------------------------*/
|
||
|
|
|
||
|
|
int16_t WebRtcIlbcfix_FrameClassify(
|
||
|
|
/* (o) Index to the max-energy sub frame */
|
||
|
|
iLBC_Enc_Inst_t *iLBCenc_inst,
|
||
|
|
/* (i/o) the encoder state structure */
|
||
|
|
int16_t *residualFIX /* (i) lpc residual signal */
|
||
|
|
){
|
||
|
|
int16_t max, scale;
|
||
|
|
int32_t ssqEn[NSUB_MAX-1];
|
||
|
|
int16_t *ssqPtr;
|
||
|
|
int32_t *seqEnPtr;
|
||
|
|
int32_t maxW32;
|
||
|
|
int16_t scale1;
|
||
|
|
int16_t pos;
|
||
|
|
int n;
|
||
|
|
|
||
|
|
/*
|
||
|
|
Calculate the energy of each of the 80 sample blocks
|
||
|
|
in the draft the 4 first and last samples are windowed with 1/5...4/5
|
||
|
|
and 4/5...1/5 respectively. To simplify for the fixpoint we have changed
|
||
|
|
this to 0 0 1 1 and 1 1 0 0
|
||
|
|
*/
|
||
|
|
|
||
|
|
max = WebRtcSpl_MaxAbsValueW16(residualFIX, iLBCenc_inst->blockl);
|
||
|
|
scale=WebRtcSpl_GetSizeInBits(WEBRTC_SPL_MUL_16_16(max,max));
|
||
|
|
|
||
|
|
/* Scale to maximum 24 bits so that it won't overflow for 76 samples */
|
||
|
|
scale = scale-24;
|
||
|
|
scale1 = WEBRTC_SPL_MAX(0, scale);
|
||
|
|
|
||
|
|
/* Calculate energies */
|
||
|
|
ssqPtr=residualFIX + 2;
|
||
|
|
seqEnPtr=ssqEn;
|
||
|
|
for (n=(iLBCenc_inst->nsub-1); n>0; n--) {
|
||
|
|
(*seqEnPtr) = WebRtcSpl_DotProductWithScale(ssqPtr, ssqPtr, 76, scale1);
|
||
|
|
ssqPtr += 40;
|
||
|
|
seqEnPtr++;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Scale to maximum 20 bits in order to allow for the 11 bit window */
|
||
|
|
maxW32 = WebRtcSpl_MaxValueW32(ssqEn, (int16_t)(iLBCenc_inst->nsub-1));
|
||
|
|
scale = WebRtcSpl_GetSizeInBits(maxW32) - 20;
|
||
|
|
scale1 = WEBRTC_SPL_MAX(0, scale);
|
||
|
|
|
||
|
|
/* Window each 80 block with the ssqEn_winTbl window to give higher probability for
|
||
|
|
the blocks in the middle
|
||
|
|
*/
|
||
|
|
seqEnPtr=ssqEn;
|
||
|
|
if (iLBCenc_inst->mode==20) {
|
||
|
|
ssqPtr=(int16_t*)WebRtcIlbcfix_kStartSequenceEnrgWin+1;
|
||
|
|
} else {
|
||
|
|
ssqPtr=(int16_t*)WebRtcIlbcfix_kStartSequenceEnrgWin;
|
||
|
|
}
|
||
|
|
for (n=(iLBCenc_inst->nsub-1); n>0; n--) {
|
||
|
|
(*seqEnPtr)=WEBRTC_SPL_MUL(((*seqEnPtr)>>scale1), (*ssqPtr));
|
||
|
|
seqEnPtr++;
|
||
|
|
ssqPtr++;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* Extract the best choise of start state */
|
||
|
|
pos = WebRtcSpl_MaxIndexW32(ssqEn, (int16_t)(iLBCenc_inst->nsub-1)) + 1;
|
||
|
|
|
||
|
|
return(pos);
|
||
|
|
}
|