1 /* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 /****************************************************************** 12 13 iLBC Speech Coder ANSI-C Source Code 14 15 WebRtcIlbcfix_EnergyInverse.c 16 17 ******************************************************************/ 18 19 /* Inverses the in vector in into Q29 domain */ 20 21 #include "energy_inverse.h" 22 23 void WebRtcIlbcfix_EnergyInverse( 24 int16_t *energy, /* (i/o) Energy and inverse 25 energy (in Q29) */ 26 size_t noOfEnergies) /* (i) The length of the energy 27 vector */ 28 { 29 int32_t Nom=(int32_t)0x1FFFFFFF; 30 int16_t *energyPtr; 31 size_t i; 32 33 /* Set the minimum energy value to 16384 to avoid overflow */ 34 energyPtr=energy; 35 for (i=0; i<noOfEnergies; i++) { 36 (*energyPtr)=WEBRTC_SPL_MAX((*energyPtr),16384); 37 energyPtr++; 38 } 39 40 /* Calculate inverse energy in Q29 */ 41 energyPtr=energy; 42 for (i=0; i<noOfEnergies; i++) { 43 (*energyPtr) = (int16_t)WebRtcSpl_DivW32W16(Nom, (*energyPtr)); 44 energyPtr++; 45 } 46 } 47
