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/*
* 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 implementations of the randomization functions
* WebRtcSpl_IncreaseSeed()
* WebRtcSpl_RandU()
* WebRtcSpl_RandN()
* WebRtcSpl_RandUArray()
*
* The description header can be found in signal_processing_library.h
*
*/
#include "signal_processing_library.h"
WebRtc_UWord32 WebRtcSpl_IncreaseSeed(WebRtc_UWord32 *seed)
{
seed[0] = (seed[0] * ((WebRtc_Word32)69069) + 1) & (WEBRTC_SPL_MAX_SEED_USED - 1);
return seed[0];
}
WebRtc_Word16 WebRtcSpl_RandU(WebRtc_UWord32 *seed)
{
return (WebRtc_Word16)(WebRtcSpl_IncreaseSeed(seed) >> 16);
}
WebRtc_Word16 WebRtcSpl_RandN(WebRtc_UWord32 *seed)
{
return WebRtcSpl_kRandNTable[WebRtcSpl_IncreaseSeed(seed) >> 23];
}
// Creates an array of uniformly distributed variables
WebRtc_Word16 WebRtcSpl_RandUArray(WebRtc_Word16* vector,
WebRtc_Word16 vector_length,
WebRtc_UWord32* seed)
{
int i;
for (i = 0; i < vector_length; i++)
{
vector[i] = WebRtcSpl_RandU(seed);
}
return vector_length;
}
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