bcec8b0b21
This is from the upstream library commit id 3326535126e435f1ba647885ce43a8f0f3d317eb, corresponding to Chromium 88.0.4290.1.
60 lines
1.4 KiB
C
60 lines
1.4 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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* This file contains the function WebRtcSpl_ReflCoefToLpc().
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* The description header can be found in signal_processing_library.h
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*
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*/
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#include "common_audio/signal_processing/include/signal_processing_library.h"
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void WebRtcSpl_ReflCoefToLpc(const int16_t *k, int use_order, int16_t *a)
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{
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int16_t any[WEBRTC_SPL_MAX_LPC_ORDER + 1];
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int16_t *aptr, *aptr2, *anyptr;
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const int16_t *kptr;
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int m, i;
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kptr = k;
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*a = 4096; // i.e., (Word16_MAX >> 3)+1.
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*any = *a;
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a[1] = *k >> 3;
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for (m = 1; m < use_order; m++)
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{
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kptr++;
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aptr = a;
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aptr++;
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aptr2 = &a[m];
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anyptr = any;
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anyptr++;
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any[m + 1] = *kptr >> 3;
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for (i = 0; i < m; i++)
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{
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*anyptr = *aptr + (int16_t)((*aptr2 * *kptr) >> 15);
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anyptr++;
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aptr++;
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aptr2--;
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}
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aptr = a;
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anyptr = any;
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for (i = 0; i < (m + 2); i++)
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{
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*aptr = *anyptr;
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aptr++;
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anyptr++;
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}
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}
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}
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