1 /* 2 * Copyright (c) 2012 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 #include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" 12 #include "webrtc/modules/audio_coding/codecs/isac/fix/source/pitch_estimator.h" 13 14 /* Filter coefficicients in Q15. */ 15 static const int16_t kDampFilter[PITCH_DAMPORDER] = { 16 -2294, 8192, 20972, 8192, -2294 17 }; 18 19 void WebRtcIsacfix_PitchFilterCore(int loopNumber, 20 int16_t gain, 21 size_t index, 22 int16_t sign, 23 int16_t* inputState, 24 int16_t* outputBuf2, 25 const int16_t* coefficient, 26 int16_t* inputBuf, 27 int16_t* outputBuf, 28 int* index2) { 29 int i = 0, j = 0; /* Loop counters. */ 30 int16_t* ubufQQpos2 = &outputBuf2[PITCH_BUFFSIZE - (index + 2)]; 31 int16_t tmpW16 = 0; 32 33 for (i = 0; i < loopNumber; i++) { 34 int32_t tmpW32 = 0; 35 36 /* Filter to get fractional pitch. */ 37 for (j = 0; j < PITCH_FRACORDER; j++) { 38 tmpW32 += ubufQQpos2[*index2 + j] * coefficient[j]; 39 } 40 41 /* Saturate to avoid overflow in tmpW16. */ 42 tmpW32 = WEBRTC_SPL_SAT(536862719, tmpW32, -536879104); 43 tmpW32 += 8192; 44 tmpW16 = (int16_t)(tmpW32 >> 14); 45 46 /* Shift low pass filter state. */ 47 memmove(&inputState[1], &inputState[0], 48 (PITCH_DAMPORDER - 1) * sizeof(int16_t)); 49 inputState[0] = (int16_t)WEBRTC_SPL_MUL_16_16_RSFT_WITH_ROUND( 50 gain, tmpW16, 12); 51 52 /* Low pass filter. */ 53 tmpW32 = 0; 54 /* TODO(kma): Define a static inline function WebRtcSpl_DotProduct() 55 in spl_inl.h to replace this and other similar loops. */ 56 for (j = 0; j < PITCH_DAMPORDER; j++) { 57 tmpW32 += inputState[j] * kDampFilter[j]; 58 } 59 60 /* Saturate to avoid overflow in tmpW16. */ 61 tmpW32 = WEBRTC_SPL_SAT(1073725439, tmpW32, -1073758208); 62 tmpW32 += 16384; 63 tmpW16 = (int16_t)(tmpW32 >> 15); 64 65 /* Subtract from input and update buffer. */ 66 tmpW32 = inputBuf[*index2] - sign * tmpW16; 67 outputBuf[*index2] = WebRtcSpl_SatW32ToW16(tmpW32); 68 tmpW32 = inputBuf[*index2] + outputBuf[*index2]; 69 outputBuf2[*index2 + PITCH_BUFFSIZE] = WebRtcSpl_SatW32ToW16(tmpW32); 70 71 (*index2)++; 72 } 73 } 74
