1e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent/* 2e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * 4e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * Use of this source code is governed by a BSD-style license 5e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * that can be found in the LICENSE file in the root of the source 6e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * tree. An additional intellectual property rights grant can be found 7e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * in the file PATENTS. All contributing project authors may 8e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * be found in the AUTHORS file in the root of the source tree. 9e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent */ 10e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 11e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 12e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent/* 13e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * This file contains the function WebRtcSpl_GetScalingSquare(). 14e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * The description header can be found in signal_processing_library.h 15e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent * 16e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent */ 17e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 18e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent#include "signal_processing_library.h" 19e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 20e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurentint WebRtcSpl_GetScalingSquare(WebRtc_Word16 *in_vector, int in_vector_length, int times) 21e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent{ 22e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent int nbits = WebRtcSpl_GetSizeInBits(times); 23e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent int i; 24e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent WebRtc_Word16 smax = -1; 25e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent WebRtc_Word16 sabs; 26e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent WebRtc_Word16 *sptr = in_vector; 27e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent int t; 28e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent int looptimes = in_vector_length; 29e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 30e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent for (i = looptimes; i > 0; i--) 31e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent { 32e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent sabs = (*sptr > 0 ? *sptr++ : -*sptr++); 33e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent smax = (sabs > smax ? sabs : smax); 34e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent } 35e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent t = WebRtcSpl_NormW32(WEBRTC_SPL_MUL(smax, smax)); 36e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent 37e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent if (smax == 0) 38e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent { 39e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent return 0; // Since norm(0) returns 0 40e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent } else 41e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent { 42e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent return (t > nbits) ? 0 : nbits - t; 43e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent } 44e48d5845c8b35de2ab73ea055c18a61fa3a9f0beEric Laurent} 45