blob: 5e1c217e26f85476c926696bf1be29a8546ac4b0 [file] [log] [blame]
* 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
#include "defines.h"
#include "constants.h"
#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
* Recreate a specific codebook vector from the augmented part.
void WebRtcIlbcfix_CreateAugmentedVec(
size_t index, /* (i) Index for the augmented vector to be created */
int16_t *buffer, /* (i) Pointer to the end of the codebook memory that
is used for creation of the augmented codebook */
int16_t *cbVec /* (o) The constructed codebook vector */
) {
size_t ilow;
int16_t *ppo, *ppi;
int16_t cbVecTmp[4];
/* Interpolation starts 4 elements before cbVec+index, but must not start
outside |cbVec|; clamping interp_len to stay within |cbVec|.
size_t interp_len = WEBRTC_SPL_MIN(index, 4);
ilow = index - interp_len;
/* copy the first noninterpolated part */
ppo = buffer-index;
WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
/* interpolation */
ppo = buffer - interp_len;
ppi = buffer - index - interp_len;
/* perform cbVec[ilow+k] = ((ppi[k]*alphaTbl[k])>>15) +
for k = 0..interp_len-1
WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha,
interp_len, 15);
cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[interp_len - 1], interp_len, 15);
WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, interp_len,
/* copy the second noninterpolated part */
ppo = buffer - index;
/* |tempbuff2| is declared in WebRtcIlbcfix_GetCbVec and is SUBL+5 elements
long. |buffer| points one element past the end of that vector, i.e., at
tempbuff2+SUBL+5. Since ppo=buffer-index, we cannot read any more than
|index| elements from |ppo|.
|cbVec| is declared to be SUBL elements long in WebRtcIlbcfix_CbConstruct.
Therefore, we can only write SUBL-index elements to cbVec+index.
These two conditions limit the number of elements to copy.
WEBRTC_SPL_MEMCPY_W16(cbVec+index, ppo, WEBRTC_SPL_MIN(SUBL-index, index));