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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}
63 lines
1.9 KiB
C
63 lines
1.9 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_Lsf2Lsp.c
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******************************************************************/
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#include "modules/audio_coding/codecs/ilbc/lsf_to_lsp.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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/*----------------------------------------------------------------*
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* conversion from lsf to lsp coefficients
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*---------------------------------------------------------------*/
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void WebRtcIlbcfix_Lsf2Lsp(
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int16_t *lsf, /* (i) lsf in Q13 values between 0 and pi */
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int16_t *lsp, /* (o) lsp in Q15 values between -1 and 1 */
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int16_t m /* (i) number of coefficients */
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) {
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int16_t i, k;
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int16_t diff; /* difference, which is used for the
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linear approximation (Q8) */
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int16_t freq; /* normalized frequency in Q15 (0..1) */
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int32_t tmpW32;
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for(i=0; i<m; i++)
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{
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freq = (int16_t)((lsf[i] * 20861) >> 15);
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/* 20861: 1.0/(2.0*PI) in Q17 */
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/*
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Upper 8 bits give the index k and
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Lower 8 bits give the difference, which needs
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to be approximated linearly
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*/
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k = freq >> 8;
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diff = (freq&0x00ff);
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/* Guard against getting outside table */
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if (k>63) {
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k = 63;
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}
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/* Calculate linear approximation */
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tmpW32 = WebRtcIlbcfix_kCosDerivative[k] * diff;
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lsp[i] = WebRtcIlbcfix_kCos[k] + (int16_t)(tmpW32 >> 12);
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}
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return;
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}
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