blob: 0b7399bf190636d8e59e4c289dd2ae228fdc56e9 [file] [log] [blame] [edit]
/*
* 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