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d00ce747c7
Bug: webrtc:12338 Change-Id: I02613d9fca45d00e2477f334b7a0416e7912e26b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/227037 Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Artem Titov <titovartem@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34621}
83 lines
3.2 KiB
C
83 lines
3.2 KiB
C
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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/******************************************************************
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iLBC Speech Coder ANSI-C Source Code
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WebRtcIlbcfix_CreateAugmentedVec.c
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******************************************************************/
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#include "modules/audio_coding/codecs/ilbc/create_augmented_vec.h"
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#include "common_audio/signal_processing/include/signal_processing_library.h"
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#include "modules/audio_coding/codecs/ilbc/constants.h"
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#include "modules/audio_coding/codecs/ilbc/defines.h"
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#include "rtc_base/sanitizer.h"
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/*----------------------------------------------------------------*
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* Recreate a specific codebook vector from the augmented part.
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*
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*----------------------------------------------------------------*/
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void WebRtcIlbcfix_CreateAugmentedVec(
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size_t index, /* (i) Index for the augmented vector to be
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created */
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const int16_t* buffer, /* (i) Pointer to the end of the codebook memory
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that is used for creation of the augmented
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codebook */
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int16_t* cbVec) { /* (o) The constructed codebook vector */
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size_t ilow;
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const int16_t *ppo, *ppi;
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int16_t cbVecTmp[4];
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/* Interpolation starts 4 elements before cbVec+index, but must not start
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outside `cbVec`; clamping interp_len to stay within `cbVec`.
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*/
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size_t interp_len = WEBRTC_SPL_MIN(index, 4);
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rtc_MsanCheckInitialized(buffer - index - interp_len, sizeof(buffer[0]),
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index + interp_len);
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ilow = index - interp_len;
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/* copy the first noninterpolated part */
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ppo = buffer-index;
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WEBRTC_SPL_MEMCPY_W16(cbVec, ppo, index);
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/* interpolation */
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ppo = buffer - interp_len;
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ppi = buffer - index - interp_len;
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/* perform cbVec[ilow+k] = ((ppi[k]*alphaTbl[k])>>15) +
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((ppo[k]*alphaTbl[interp_len-1-k])>>15);
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for k = 0..interp_len-1
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*/
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WebRtcSpl_ElementwiseVectorMult(&cbVec[ilow], ppi, WebRtcIlbcfix_kAlpha,
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interp_len, 15);
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WebRtcSpl_ReverseOrderMultArrayElements(
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cbVecTmp, ppo, &WebRtcIlbcfix_kAlpha[interp_len - 1], interp_len, 15);
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WebRtcSpl_AddVectorsAndShift(&cbVec[ilow], &cbVec[ilow], cbVecTmp, interp_len,
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0);
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/* copy the second noninterpolated part */
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ppo = buffer - index;
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/* `tempbuff2` is declared in WebRtcIlbcfix_GetCbVec and is SUBL+5 elements
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long. `buffer` points one element past the end of that vector, i.e., at
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tempbuff2+SUBL+5. Since ppo=buffer-index, we cannot read any more than
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`index` elements from `ppo`.
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`cbVec` is declared to be SUBL elements long in WebRtcIlbcfix_CbConstruct.
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Therefore, we can only write SUBL-index elements to cbVec+index.
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These two conditions limit the number of elements to copy.
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*/
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WEBRTC_SPL_MEMCPY_W16(cbVec+index, ppo, WEBRTC_SPL_MIN(SUBL-index, index));
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}
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