1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 119fb16139d917ba32720e031d3c871987d418668fpbos@webrtc.org#include "webrtc/modules/audio_processing/high_pass_filter_impl.h" 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 133f45c2e0ac4cb280f941efa3a3476895795e3dd6pbos@webrtc.org#include <assert.h> 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 159fb16139d917ba32720e031d3c871987d418668fpbos@webrtc.org#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" 16a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org#include "webrtc/modules/audio_processing/audio_buffer.h" 179fb16139d917ba32720e031d3c871987d418668fpbos@webrtc.org#include "webrtc/system_wrappers/interface/critical_section_wrapper.h" 189fb16139d917ba32720e031d3c871987d418668fpbos@webrtc.org#include "webrtc/typedefs.h" 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgnamespace webrtc { 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgnamespace { 233f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.orgconst int16_t kFilterCoefficients8kHz[5] = 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org {3798, -7596, 3798, 7807, -3733}; 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 263f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.orgconst int16_t kFilterCoefficients[5] = 27b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org {4012, -8024, 4012, 8002, -3913}; 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgstruct FilterState { 303f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org int16_t y[4]; 313f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org int16_t x[2]; 323f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org const int16_t* ba; 33b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org}; 34b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint InitializeFilter(FilterState* hpf, int sample_rate_hz) { 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org assert(hpf != NULL); 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 38a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org if (sample_rate_hz == AudioProcessing::kSampleRate8kHz) { 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org hpf->ba = kFilterCoefficients8kHz; 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } else { 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org hpf->ba = kFilterCoefficients; 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcSpl_MemSetW16(hpf->x, 0, 2); 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WebRtcSpl_MemSetW16(hpf->y, 0, 4); 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return AudioProcessing::kNoError; 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 503f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.orgint Filter(FilterState* hpf, int16_t* data, int length) { 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org assert(hpf != NULL); 52b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 533f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org int32_t tmp_int32 = 0; 543f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org int16_t* y = hpf->y; 553f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org int16_t* x = hpf->x; 563f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org const int16_t* ba = hpf->ba; 57b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 58b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org for (int i = 0; i < length; i++) { 59b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // y[i] = b[0] * x[i] + b[1] * x[i-1] + b[2] * x[i-2] 60b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // + -a[1] * y[i-1] + -a[2] * y[i-2]; 61b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 62b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 = 63b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WEBRTC_SPL_MUL_16_16(y[1], ba[3]); // -a[1] * y[i-1] (low part) 64b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += 65b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WEBRTC_SPL_MUL_16_16(y[3], ba[4]); // -a[2] * y[i-2] (low part) 66b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 = (tmp_int32 >> 15); 67b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += 68b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WEBRTC_SPL_MUL_16_16(y[0], ba[3]); // -a[1] * y[i-1] (high part) 69b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += 70b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org WEBRTC_SPL_MUL_16_16(y[2], ba[4]); // -a[2] * y[i-2] (high part) 71b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 = (tmp_int32 << 1); 72b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 73b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += WEBRTC_SPL_MUL_16_16(data[i], ba[0]); // b[0]*x[0] 74b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += WEBRTC_SPL_MUL_16_16(x[0], ba[1]); // b[1]*x[i-1] 75b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += WEBRTC_SPL_MUL_16_16(x[1], ba[2]); // b[2]*x[i-2] 76b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 77b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // Update state (input part) 78b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org x[1] = x[0]; 79b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org x[0] = data[i]; 80b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 81b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // Update state (filtered part) 82b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org y[2] = y[0]; 83b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org y[3] = y[1]; 843f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org y[0] = static_cast<int16_t>(tmp_int32 >> 13); 853f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org y[1] = static_cast<int16_t>((tmp_int32 - 863f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org WEBRTC_SPL_LSHIFT_W32(static_cast<int32_t>(y[0]), 13)) << 2); 87b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 88b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // Rounding in Q12, i.e. add 2^11 89b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32 += 2048; 90b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 91b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // Saturate (to 2^27) so that the HP filtered signal does not overflow 923f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org tmp_int32 = WEBRTC_SPL_SAT(static_cast<int32_t>(134217727), 93b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org tmp_int32, 943f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org static_cast<int32_t>(-134217728)); 95b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 96b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // Convert back to Q0 and use rounding 973f6d5e0bded85b8b0d055da8fa49e8d7137fe8edpbos@webrtc.org data[i] = (int16_t)WEBRTC_SPL_RSHIFT_W32(tmp_int32, 12); 98b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 99b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 100b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 101b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return AudioProcessing::kNoError; 102b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 103b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} // namespace 104b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 105b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgtypedef FilterState Handle; 106b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 107a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.orgHighPassFilterImpl::HighPassFilterImpl(const AudioProcessing* apm, 108a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org CriticalSectionWrapper* crit) 109a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org : ProcessingComponent(), 110a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org apm_(apm), 111a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org crit_(crit) {} 112b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 113b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgHighPassFilterImpl::~HighPassFilterImpl() {} 114b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 115b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::ProcessCaptureAudio(AudioBuffer* audio) { 116b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int err = apm_->kNoError; 117b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 118b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (!is_component_enabled()) { 119b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return apm_->kNoError; 120b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 121b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 122b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org assert(audio->samples_per_split_channel() <= 160); 123b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 124b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org for (int i = 0; i < num_handles(); i++) { 125b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org Handle* my_handle = static_cast<Handle*>(handle(i)); 126b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org err = Filter(my_handle, 127b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org audio->low_pass_split_data(i), 128b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org audio->samples_per_split_channel()); 129b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 130b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org if (err != apm_->kNoError) { 131b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return GetHandleError(my_handle); 132b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 133b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org } 134b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 135b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return apm_->kNoError; 136b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 137b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 138b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::Enable(bool enable) { 139a1a60018a1f1ec863451ad0ed4eae58239882920andrew@webrtc.org CriticalSectionScoped crit_scoped(crit_); 140b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return EnableComponent(enable); 141b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 142b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 143b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgbool HighPassFilterImpl::is_enabled() const { 144b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return is_component_enabled(); 145b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 146b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 147b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgvoid* HighPassFilterImpl::CreateHandle() const { 148b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return new FilterState; 149b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 150b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 151ffc2de0133683fb103eef61f21134f469bc099dbbjornv@webrtc.orgvoid HighPassFilterImpl::DestroyHandle(void* handle) const { 152b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org delete static_cast<Handle*>(handle); 153b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 154b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 155b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::InitializeHandle(void* handle) const { 156b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return InitializeFilter(static_cast<Handle*>(handle), 157467f7567c8befea153861e09f048f69932d6e3bdandrew@webrtc.org apm_->proc_sample_rate_hz()); 158b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 159b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 160b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::ConfigureHandle(void* /*handle*/) const { 161b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return apm_->kNoError; // Not configurable. 162b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 163b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 164b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::num_handles_required() const { 165b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return apm_->num_output_channels(); 166b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 167b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 168b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint HighPassFilterImpl::GetHandleError(void* handle) const { 169b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org // The component has no detailed errors. 170b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org assert(handle != NULL); 171b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org return apm_->kUnspecifiedError; 172b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} 173b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org} // namespace webrtc 174