diff options
Diffstat (limited to 'webrtc/modules/audio_processing/high_pass_filter_impl.cc')
| -rw-r--r-- | webrtc/modules/audio_processing/high_pass_filter_impl.cc | 168 |
1 files changed, 0 insertions, 168 deletions
diff --git a/webrtc/modules/audio_processing/high_pass_filter_impl.cc b/webrtc/modules/audio_processing/high_pass_filter_impl.cc deleted file mode 100644 index 29e4820..0000000 --- a/webrtc/modules/audio_processing/high_pass_filter_impl.cc +++ /dev/null @@ -1,168 +0,0 @@ -/* - * Copyright (c) 2012 The WebRTC project authors. All Rights Reserved. - * - * Use of this source code is governed by a BSD-style license - * that can be found in the LICENSE file in the root of the source - * tree. An additional intellectual property rights grant can be found - * in the file PATENTS. All contributing project authors may - * be found in the AUTHORS file in the root of the source tree. - */ - -#include "webrtc/modules/audio_processing/high_pass_filter_impl.h" - -#include <assert.h> - -#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h" -#include "webrtc/modules/audio_processing/audio_buffer.h" -#include "webrtc/system_wrappers/include/critical_section_wrapper.h" -#include "webrtc/typedefs.h" - - -namespace webrtc { -namespace { -const int16_t kFilterCoefficients8kHz[5] = - {3798, -7596, 3798, 7807, -3733}; - -const int16_t kFilterCoefficients[5] = - {4012, -8024, 4012, 8002, -3913}; - -struct FilterState { - int16_t y[4]; - int16_t x[2]; - const int16_t* ba; -}; - -int InitializeFilter(FilterState* hpf, int sample_rate_hz) { - assert(hpf != NULL); - - if (sample_rate_hz == AudioProcessing::kSampleRate8kHz) { - hpf->ba = kFilterCoefficients8kHz; - } else { - hpf->ba = kFilterCoefficients; - } - - WebRtcSpl_MemSetW16(hpf->x, 0, 2); - WebRtcSpl_MemSetW16(hpf->y, 0, 4); - - return AudioProcessing::kNoError; -} - -int Filter(FilterState* hpf, int16_t* data, size_t length) { - assert(hpf != NULL); - - int32_t tmp_int32 = 0; - int16_t* y = hpf->y; - int16_t* x = hpf->x; - const int16_t* ba = hpf->ba; - - for (size_t i = 0; i < length; i++) { - // y[i] = b[0] * x[i] + b[1] * x[i-1] + b[2] * x[i-2] - // + -a[1] * y[i-1] + -a[2] * y[i-2]; - - tmp_int32 = y[1] * ba[3]; // -a[1] * y[i-1] (low part) - tmp_int32 += y[3] * ba[4]; // -a[2] * y[i-2] (low part) - tmp_int32 = (tmp_int32 >> 15); - tmp_int32 += y[0] * ba[3]; // -a[1] * y[i-1] (high part) - tmp_int32 += y[2] * ba[4]; // -a[2] * y[i-2] (high part) - tmp_int32 = (tmp_int32 << 1); - - tmp_int32 += data[i] * ba[0]; // b[0]*x[0] - tmp_int32 += x[0] * ba[1]; // b[1]*x[i-1] - tmp_int32 += x[1] * ba[2]; // b[2]*x[i-2] - - // Update state (input part) - x[1] = x[0]; - x[0] = data[i]; - - // Update state (filtered part) - y[2] = y[0]; - y[3] = y[1]; - y[0] = static_cast<int16_t>(tmp_int32 >> 13); - y[1] = static_cast<int16_t>( - (tmp_int32 - (static_cast<int32_t>(y[0]) << 13)) << 2); - - // Rounding in Q12, i.e. add 2^11 - tmp_int32 += 2048; - - // Saturate (to 2^27) so that the HP filtered signal does not overflow - tmp_int32 = WEBRTC_SPL_SAT(static_cast<int32_t>(134217727), - tmp_int32, - static_cast<int32_t>(-134217728)); - - // Convert back to Q0 and use rounding. - data[i] = (int16_t)(tmp_int32 >> 12); - } - - return AudioProcessing::kNoError; -} -} // namespace - -typedef FilterState Handle; - -HighPassFilterImpl::HighPassFilterImpl(const AudioProcessing* apm, - CriticalSectionWrapper* crit) - : ProcessingComponent(), - apm_(apm), - crit_(crit) {} - -HighPassFilterImpl::~HighPassFilterImpl() {} - -int HighPassFilterImpl::ProcessCaptureAudio(AudioBuffer* audio) { - int err = apm_->kNoError; - - if (!is_component_enabled()) { - return apm_->kNoError; - } - - assert(audio->num_frames_per_band() <= 160); - - for (int i = 0; i < num_handles(); i++) { - Handle* my_handle = static_cast<Handle*>(handle(i)); - err = Filter(my_handle, - audio->split_bands(i)[kBand0To8kHz], - audio->num_frames_per_band()); - - if (err != apm_->kNoError) { - return GetHandleError(my_handle); - } - } - - return apm_->kNoError; -} - -int HighPassFilterImpl::Enable(bool enable) { - CriticalSectionScoped crit_scoped(crit_); - return EnableComponent(enable); -} - -bool HighPassFilterImpl::is_enabled() const { - return is_component_enabled(); -} - -void* HighPassFilterImpl::CreateHandle() const { - return new FilterState; -} - -void HighPassFilterImpl::DestroyHandle(void* handle) const { - delete static_cast<Handle*>(handle); -} - -int HighPassFilterImpl::InitializeHandle(void* handle) const { - return InitializeFilter(static_cast<Handle*>(handle), - apm_->proc_sample_rate_hz()); -} - -int HighPassFilterImpl::ConfigureHandle(void* /*handle*/) const { - return apm_->kNoError; // Not configurable. -} - -int HighPassFilterImpl::num_handles_required() const { - return apm_->num_output_channels(); -} - -int HighPassFilterImpl::GetHandleError(void* handle) const { - // The component has no detailed errors. - assert(handle != NULL); - return apm_->kUnspecifiedError; -} -} // namespace webrtc |