47 lines
1.2 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_GetScaling().
* The description header can be found in signal_processing_library.h
*
*/
#include "signal_processing_library.h"
int WebRtcSpl_GetScaling(WebRtc_Word16 *in_vector, int in_vector_length, int times)
{
int nbits = WebRtcSpl_GetSizeInBits(times);
int i;
WebRtc_Word16 sabs;
int t;
WebRtc_Word16 *sptr = in_vector;
WebRtc_Word16 smax = *sptr++;
for (i = in_vector_length - 1; i > 0; i--)
{
sabs = WEBRTC_SPL_ABS_W16 (*sptr);
sptr++;
if (sabs > smax)
smax = sabs;
}
t = WebRtcSpl_NormW32((WebRtc_Word32)smax << 16);
if (smax == 0)
{
return 0; // Since norm(0) returns 0
} else
{
return (t > nbits) ? 0 : nbits - t;
}
}