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3111783aa1
Prior to this commit, most .c files in modules/audio_coding/codecs/ilbc don't include their corresponding headers, nor do they order #includes as per the Google Style Guide [1]. The former is especially harmful, since in C it can silently allow the function signature to diverge from its prototype, thus causing disaster at runtime. This CL fixes both issues. In effect, this allows the common_audio and modules/audio_coding:ilbc targets to be compiled with Clang's -Wmissing-prototypes, though this CL does not add that change. [1]: https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes Bug: webrtc:12314 Change-Id: I8299968ed3cc86ff35d9de045072b846298043af Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198362 Reviewed-by: Henrik Lundin <henrik.lundin@webrtc.org> Commit-Queue: Timothy Gu <timothygu@chromium.org> Cr-Commit-Position: refs/heads/master@{#32896}
84 lines
2 KiB
C
84 lines
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_GetLspPoly.c
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******************************************************************/
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#include "modules/audio_coding/codecs/ilbc/get_lsp_poly.h"
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#include "modules/audio_coding/codecs/ilbc/defines.h"
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/*----------------------------------------------------------------*
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* Construct the polynomials F1(z) and F2(z) from the LSP
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* (Computations are done in Q24)
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*
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* The expansion is performed using the following recursion:
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*
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* f[0] = 1;
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* tmp = -2.0 * lsp[0];
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* f[1] = tmp;
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* for (i=2; i<=5; i++) {
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* b = -2.0 * lsp[2*i-2];
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* f[i] = tmp*f[i-1] + 2.0*f[i-2];
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* for (j=i; j>=2; j--) {
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* f[j] = f[j] + tmp*f[j-1] + f[j-2];
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* }
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* f[i] = f[i] + tmp;
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* }
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*---------------------------------------------------------------*/
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void WebRtcIlbcfix_GetLspPoly(
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int16_t *lsp, /* (i) LSP in Q15 */
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int32_t *f) /* (o) polonymial in Q24 */
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{
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int32_t tmpW32;
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int i, j;
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int16_t high, low;
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int16_t *lspPtr;
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int32_t *fPtr;
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lspPtr = lsp;
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fPtr = f;
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/* f[0] = 1.0 (Q24) */
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(*fPtr) = (int32_t)16777216;
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fPtr++;
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(*fPtr) = WEBRTC_SPL_MUL((*lspPtr), -1024);
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fPtr++;
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lspPtr+=2;
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for(i=2; i<=5; i++)
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{
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(*fPtr) = fPtr[-2];
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for(j=i; j>1; j--)
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{
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/* Compute f[j] = f[j] + tmp*f[j-1] + f[j-2]; */
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high = (int16_t)(fPtr[-1] >> 16);
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low = (int16_t)((fPtr[-1] & 0xffff) >> 1);
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tmpW32 = 4 * high * *lspPtr + 4 * ((low * *lspPtr) >> 15);
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(*fPtr) += fPtr[-2];
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(*fPtr) -= tmpW32;
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fPtr--;
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}
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*fPtr -= *lspPtr * (1 << 10);
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fPtr+=i;
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lspPtr+=2;
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}
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return;
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}
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