1/* 2 * Copyright (c) 2014 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/fir_filter.h" 12 13#include <assert.h> 14#include <string.h> 15 16#include "webrtc/common_audio/fir_filter_neon.h" 17#include "webrtc/common_audio/fir_filter_sse.h" 18#include "webrtc/system_wrappers/interface/cpu_features_wrapper.h" 19#include "webrtc/system_wrappers/interface/scoped_ptr.h" 20 21namespace webrtc { 22 23class FIRFilterC : public FIRFilter { 24 public: 25 FIRFilterC(const float* coefficients, 26 size_t coefficients_length); 27 28 virtual void Filter(const float* in, size_t length, float* out) OVERRIDE; 29 30 private: 31 size_t coefficients_length_; 32 size_t state_length_; 33 scoped_ptr<float[]> coefficients_; 34 scoped_ptr<float[]> state_; 35}; 36 37FIRFilter* FIRFilter::Create(const float* coefficients, 38 size_t coefficients_length, 39 size_t max_input_length) { 40 if (!coefficients || coefficients_length <= 0 || max_input_length <= 0) { 41 assert(false); 42 return NULL; 43 } 44 45 FIRFilter* filter = NULL; 46// If we know the minimum architecture at compile time, avoid CPU detection. 47#if defined(WEBRTC_ARCH_X86_FAMILY) 48#if defined(__SSE2__) 49 filter = 50 new FIRFilterSSE2(coefficients, coefficients_length, max_input_length); 51#else 52 // x86 CPU detection required. 53 if (WebRtc_GetCPUInfo(kSSE2)) { 54 filter = 55 new FIRFilterSSE2(coefficients, coefficients_length, max_input_length); 56 } else { 57 filter = new FIRFilterC(coefficients, coefficients_length); 58 } 59#endif 60#elif defined(WEBRTC_ARCH_ARM_V7) 61#if defined(WEBRTC_ARCH_ARM_NEON) 62 filter = 63 new FIRFilterNEON(coefficients, coefficients_length, max_input_length); 64#else 65 // ARM CPU detection required. 66 if (WebRtc_GetCPUFeaturesARM() & kCPUFeatureNEON) { 67 filter = 68 new FIRFilterNEON(coefficients, coefficients_length, max_input_length); 69 } else { 70 filter = new FIRFilterC(coefficients, coefficients_length); 71 } 72#endif 73#else 74 filter = new FIRFilterC(coefficients, coefficients_length); 75#endif 76 77 return filter; 78} 79 80FIRFilterC::FIRFilterC(const float* coefficients, size_t coefficients_length) 81 : coefficients_length_(coefficients_length), 82 state_length_(coefficients_length - 1), 83 coefficients_(new float[coefficients_length_]), 84 state_(new float[state_length_]) { 85 for (size_t i = 0; i < coefficients_length_; ++i) { 86 coefficients_[i] = coefficients[coefficients_length_ - i - 1]; 87 } 88 memset(state_.get(), 0, state_length_ * sizeof(state_[0])); 89} 90 91void FIRFilterC::Filter(const float* in, size_t length, float* out) { 92 assert(length > 0); 93 94 // Convolves the input signal |in| with the filter kernel |coefficients_| 95 // taking into account the previous state. 96 for (size_t i = 0; i < length; ++i) { 97 out[i] = 0.f; 98 size_t j; 99 for (j = 0; state_length_ > i && j < state_length_ - i; ++j) { 100 out[i] += state_[i + j] * coefficients_[j]; 101 } 102 for (; j < coefficients_length_; ++j) { 103 out[i] += in[j + i - state_length_] * coefficients_[j]; 104 } 105 } 106 107 // Update current state. 108 if (length >= state_length_) { 109 memcpy( 110 state_.get(), &in[length - state_length_], state_length_ * sizeof(*in)); 111 } else { 112 memmove(state_.get(), 113 &state_[length], 114 (state_length_ - length) * sizeof(state_[0])); 115 memcpy(&state_[state_length_ - length], in, length * sizeof(*in)); 116 } 117} 118 119} // namespace webrtc 120