| /* |
| * Copyright (c) 2014 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 "modules/audio_processing/splitting_filter.h" |
| |
| #include <array> |
| |
| #include "api/array_view.h" |
| #include "common_audio/channel_buffer.h" |
| #include "common_audio/signal_processing/include/signal_processing_library.h" |
| #include "rtc_base/checks.h" |
| |
| namespace webrtc { |
| namespace { |
| |
| constexpr size_t kSamplesPerBand = 160; |
| constexpr size_t kTwoBandFilterSamplesPerFrame = 320; |
| |
| } // namespace |
| |
| SplittingFilter::SplittingFilter(size_t num_channels, |
| size_t num_bands, |
| size_t /* num_frames */) |
| : num_bands_(num_bands), |
| two_bands_states_(num_bands_ == 2 ? num_channels : 0), |
| three_band_filter_banks_(num_bands_ == 3 ? num_channels : 0) { |
| RTC_CHECK(num_bands_ == 2 || num_bands_ == 3); |
| } |
| |
| SplittingFilter::~SplittingFilter() = default; |
| |
| void SplittingFilter::Analysis(const ChannelBuffer<float>* data, |
| ChannelBuffer<float>* bands) { |
| RTC_DCHECK_EQ(num_bands_, bands->num_bands()); |
| RTC_DCHECK_EQ(data->num_channels(), bands->num_channels()); |
| RTC_DCHECK_EQ(data->num_frames(), |
| bands->num_frames_per_band() * bands->num_bands()); |
| if (bands->num_bands() == 2) { |
| TwoBandsAnalysis(data, bands); |
| } else if (bands->num_bands() == 3) { |
| ThreeBandsAnalysis(data, bands); |
| } |
| } |
| |
| void SplittingFilter::Synthesis(const ChannelBuffer<float>* bands, |
| ChannelBuffer<float>* data) { |
| RTC_DCHECK_EQ(num_bands_, bands->num_bands()); |
| RTC_DCHECK_EQ(data->num_channels(), bands->num_channels()); |
| RTC_DCHECK_EQ(data->num_frames(), |
| bands->num_frames_per_band() * bands->num_bands()); |
| if (bands->num_bands() == 2) { |
| TwoBandsSynthesis(bands, data); |
| } else if (bands->num_bands() == 3) { |
| ThreeBandsSynthesis(bands, data); |
| } |
| } |
| |
| void SplittingFilter::TwoBandsAnalysis(const ChannelBuffer<float>* data, |
| ChannelBuffer<float>* bands) { |
| RTC_DCHECK_EQ(two_bands_states_.size(), data->num_channels()); |
| RTC_DCHECK_EQ(data->num_frames(), kTwoBandFilterSamplesPerFrame); |
| |
| for (size_t i = 0; i < two_bands_states_.size(); ++i) { |
| std::array<std::array<int16_t, kSamplesPerBand>, 2> bands16; |
| std::array<int16_t, kTwoBandFilterSamplesPerFrame> full_band16; |
| FloatS16ToS16(data->channels(0)[i], full_band16.size(), full_band16.data()); |
| WebRtcSpl_AnalysisQMF(full_band16.data(), data->num_frames(), |
| bands16[0].data(), bands16[1].data(), |
| two_bands_states_[i].analysis_state1, |
| two_bands_states_[i].analysis_state2); |
| S16ToFloatS16(bands16[0].data(), bands16[0].size(), bands->channels(0)[i]); |
| S16ToFloatS16(bands16[1].data(), bands16[1].size(), bands->channels(1)[i]); |
| } |
| } |
| |
| void SplittingFilter::TwoBandsSynthesis(const ChannelBuffer<float>* bands, |
| ChannelBuffer<float>* data) { |
| RTC_DCHECK_LE(data->num_channels(), two_bands_states_.size()); |
| RTC_DCHECK_EQ(data->num_frames(), kTwoBandFilterSamplesPerFrame); |
| for (size_t i = 0; i < data->num_channels(); ++i) { |
| std::array<std::array<int16_t, kSamplesPerBand>, 2> bands16; |
| std::array<int16_t, kTwoBandFilterSamplesPerFrame> full_band16; |
| FloatS16ToS16(bands->channels(0)[i], bands16[0].size(), bands16[0].data()); |
| FloatS16ToS16(bands->channels(1)[i], bands16[1].size(), bands16[1].data()); |
| WebRtcSpl_SynthesisQMF(bands16[0].data(), bands16[1].data(), |
| bands->num_frames_per_band(), full_band16.data(), |
| two_bands_states_[i].synthesis_state1, |
| two_bands_states_[i].synthesis_state2); |
| S16ToFloatS16(full_band16.data(), full_band16.size(), data->channels(0)[i]); |
| } |
| } |
| |
| void SplittingFilter::ThreeBandsAnalysis(const ChannelBuffer<float>* data, |
| ChannelBuffer<float>* bands) { |
| RTC_DCHECK_EQ(three_band_filter_banks_.size(), data->num_channels()); |
| RTC_DCHECK_LE(data->num_channels(), three_band_filter_banks_.size()); |
| RTC_DCHECK_LE(data->num_channels(), bands->num_channels()); |
| RTC_DCHECK_EQ(data->num_frames(), ThreeBandFilterBank::kFullBandSize); |
| RTC_DCHECK_EQ(bands->num_frames(), ThreeBandFilterBank::kFullBandSize); |
| RTC_DCHECK_EQ(bands->num_bands(), ThreeBandFilterBank::kNumBands); |
| RTC_DCHECK_EQ(bands->num_frames_per_band(), |
| ThreeBandFilterBank::kSplitBandSize); |
| |
| for (size_t i = 0; i < three_band_filter_banks_.size(); ++i) { |
| three_band_filter_banks_[i].Analysis( |
| rtc::ArrayView<const float, ThreeBandFilterBank::kFullBandSize>( |
| data->channels_view()[i].data(), |
| ThreeBandFilterBank::kFullBandSize), |
| rtc::ArrayView<const rtc::ArrayView<float>, |
| ThreeBandFilterBank::kNumBands>( |
| bands->bands_view(i).data(), ThreeBandFilterBank::kNumBands)); |
| } |
| } |
| |
| void SplittingFilter::ThreeBandsSynthesis(const ChannelBuffer<float>* bands, |
| ChannelBuffer<float>* data) { |
| RTC_DCHECK_LE(data->num_channels(), three_band_filter_banks_.size()); |
| RTC_DCHECK_LE(data->num_channels(), bands->num_channels()); |
| RTC_DCHECK_LE(data->num_channels(), three_band_filter_banks_.size()); |
| RTC_DCHECK_EQ(data->num_frames(), ThreeBandFilterBank::kFullBandSize); |
| RTC_DCHECK_EQ(bands->num_frames(), ThreeBandFilterBank::kFullBandSize); |
| RTC_DCHECK_EQ(bands->num_bands(), ThreeBandFilterBank::kNumBands); |
| RTC_DCHECK_EQ(bands->num_frames_per_band(), |
| ThreeBandFilterBank::kSplitBandSize); |
| |
| for (size_t i = 0; i < data->num_channels(); ++i) { |
| three_band_filter_banks_[i].Synthesis( |
| rtc::ArrayView<const rtc::ArrayView<float>, |
| ThreeBandFilterBank::kNumBands>( |
| bands->bands_view(i).data(), ThreeBandFilterBank::kNumBands), |
| rtc::ArrayView<float, ThreeBandFilterBank::kFullBandSize>( |
| data->channels_view()[i].data(), |
| ThreeBandFilterBank::kFullBandSize)); |
| } |
| } |
| |
| } // namespace webrtc |