void WebRtcIlbcfix_CreateAugmentedVec(
WebRtc_Word16 index, /* (i) Index for the augmented vector to be created */
WebRtc_Word16 *buffer, /* (i) Pointer to the end of the codebook memory that
is used for creation of the augmented codebook */
WebRtc_Word16 *cbVec /* (o) The construced codebook vector */
) {
WebRtc_Word16 ilow;
WebRtc_Word16 *ppo, *ppi;
WebRtc_Word16 cbVecTmp[4];
ilow = index-4;
/* copy the first noninterpolated part */
ppo = buffer-index;
WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
/* interpolation */
ppo = buffer - 4;
ppi = buffer - index - 4;
/* perform cbVec[ilow+k] = ((ppi[k]*alphaTbl[k])>>15) + ((ppo[k]*alphaTbl[3-k])>>15);
for k = 0..3
*/
WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha, 4, 15);
WebRtcSpl_ReverseOrderMultArrayElements(cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[3], 4, 15);
WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, 4, 0);
/* copy the second noninterpolated part */
ppo = buffer - index;
WEBRTC_SPL_MEMCPY_W16(cbVec+index,ppo,(SUBL-index));
}
void WebRtcIlbcfix_CreateAugmentedVec(
size_t index, /* (i) Index for the augmented vector to be
created */
const 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;
const 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) +
((ppo[k]*alphaTbl[interp_len-1-k])>>15);
for k = 0..interp_len-1
*/
WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha,
interp_len, 15);
WebRtcSpl_ReverseOrderMultArrayElements(
cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[interp_len - 1], interp_len, 15);
WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, interp_len,
0);
/* 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));
}
