36 lines
1.1 KiB
C
36 lines
1.1 KiB
C
/*
|
|
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
|
|
/*
|
|
* This file contains the function WebRtcSpl_SqrtOfOneMinusXSquared().
|
|
* The description header can be found in signal_processing_library.h
|
|
*
|
|
*/
|
|
|
|
#include "common_audio/signal_processing/include/signal_processing_library.h"
|
|
|
|
void WebRtcSpl_SqrtOfOneMinusXSquared(int16_t *xQ15, size_t vector_length,
|
|
int16_t *yQ15)
|
|
{
|
|
int32_t sq;
|
|
size_t m;
|
|
int16_t tmp;
|
|
|
|
for (m = 0; m < vector_length; m++)
|
|
{
|
|
tmp = xQ15[m];
|
|
sq = tmp * tmp; // x^2 in Q30
|
|
sq = 1073741823 - sq; // 1-x^2, where 1 ~= 0.99999999906 is 1073741823 in Q30
|
|
sq = WebRtcSpl_Sqrt(sq); // sqrt(1-x^2) in Q15
|
|
yQ15[m] = (int16_t)sq;
|
|
}
|
|
}
|