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Diffstat (limited to 'externals/oboe/src/flowgraph/resampler/MultiChannelResampler.h')
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diff --git a/externals/oboe/src/flowgraph/resampler/MultiChannelResampler.h b/externals/oboe/src/flowgraph/resampler/MultiChannelResampler.h deleted file mode 100644 index 9e47335a49..0000000000 --- a/externals/oboe/src/flowgraph/resampler/MultiChannelResampler.h +++ /dev/null @@ -1,281 +0,0 @@ -/* - * Copyright 2019 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -#ifndef RESAMPLER_MULTICHANNEL_RESAMPLER_H -#define RESAMPLER_MULTICHANNEL_RESAMPLER_H - -#include <memory> -#include <vector> -#include <sys/types.h> -#include <unistd.h> - -#ifndef MCR_USE_KAISER -// It appears from the spectrogram that the HyperbolicCosine window leads to fewer artifacts. -// And it is faster to calculate. -#define MCR_USE_KAISER 0 -#endif - -#if MCR_USE_KAISER -#include "KaiserWindow.h" -#else -#include "HyperbolicCosineWindow.h" -#endif - -#include "ResamplerDefinitions.h" - -namespace RESAMPLER_OUTER_NAMESPACE::resampler { - -class MultiChannelResampler { - -public: - - enum class Quality : int32_t { - Fastest, - Low, - Medium, - High, - Best, - }; - - class Builder { - public: - /** - * Construct an optimal resampler based on the specified parameters. - * @return address of a resampler - */ - MultiChannelResampler *build(); - - /** - * The number of taps in the resampling filter. - * More taps gives better quality but uses more CPU time. - * This typically ranges from 4 to 64. Default is 16. - * - * For polyphase filters, numTaps must be a multiple of four for loop unrolling. - * @param numTaps number of taps for the filter - * @return address of this builder for chaining calls - */ - Builder *setNumTaps(int32_t numTaps) { - mNumTaps = numTaps; - return this; - } - - /** - * Use 1 for mono, 2 for stereo, etc. Default is 1. - * - * @param channelCount number of channels - * @return address of this builder for chaining calls - */ - Builder *setChannelCount(int32_t channelCount) { - mChannelCount = channelCount; - return this; - } - - /** - * Default is 48000. - * - * @param inputRate sample rate of the input stream - * @return address of this builder for chaining calls - */ - Builder *setInputRate(int32_t inputRate) { - mInputRate = inputRate; - return this; - } - - /** - * Default is 48000. - * - * @param outputRate sample rate of the output stream - * @return address of this builder for chaining calls - */ - Builder *setOutputRate(int32_t outputRate) { - mOutputRate = outputRate; - return this; - } - - /** - * Set cutoff frequency relative to the Nyquist rate of the output sample rate. - * Set to 1.0 to match the Nyquist frequency. - * Set lower to reduce aliasing. - * Default is 0.70. - * - * Note that this value is ignored when upsampling, which is when - * the outputRate is higher than the inputRate. - * - * @param normalizedCutoff anti-aliasing filter cutoff - * @return address of this builder for chaining calls - */ - Builder *setNormalizedCutoff(float normalizedCutoff) { - mNormalizedCutoff = normalizedCutoff; - return this; - } - - int32_t getNumTaps() const { - return mNumTaps; - } - - int32_t getChannelCount() const { - return mChannelCount; - } - - int32_t getInputRate() const { - return mInputRate; - } - - int32_t getOutputRate() const { - return mOutputRate; - } - - float getNormalizedCutoff() const { - return mNormalizedCutoff; - } - - protected: - int32_t mChannelCount = 1; - int32_t mNumTaps = 16; - int32_t mInputRate = 48000; - int32_t mOutputRate = 48000; - float mNormalizedCutoff = kDefaultNormalizedCutoff; - }; - - virtual ~MultiChannelResampler() = default; - - /** - * Factory method for making a resampler that is optimal for the given inputs. - * - * @param channelCount number of channels, 2 for stereo - * @param inputRate sample rate of the input stream - * @param outputRate sample rate of the output stream - * @param quality higher quality sounds better but uses more CPU - * @return an optimal resampler - */ - static MultiChannelResampler *make(int32_t channelCount, - int32_t inputRate, - int32_t outputRate, - Quality quality); - - bool isWriteNeeded() const { - return mIntegerPhase >= mDenominator; - } - - /** - * Write a frame containing N samples. - * - * @param frame pointer to the first sample in a frame - */ - void writeNextFrame(const float *frame) { - writeFrame(frame); - advanceWrite(); - } - - /** - * Read a frame containing N samples. - * - * @param frame pointer to the first sample in a frame - */ - void readNextFrame(float *frame) { - readFrame(frame); - advanceRead(); - } - - int getNumTaps() const { - return mNumTaps; - } - - int getChannelCount() const { - return mChannelCount; - } - - static float hammingWindow(float radians, float spread); - - static float sinc(float radians); - -protected: - - explicit MultiChannelResampler(const MultiChannelResampler::Builder &builder); - - /** - * Write a frame containing N samples. - * Call advanceWrite() after calling this. - * @param frame pointer to the first sample in a frame - */ - virtual void writeFrame(const float *frame); - - /** - * Read a frame containing N samples using interpolation. - * Call advanceRead() after calling this. - * @param frame pointer to the first sample in a frame - */ - virtual void readFrame(float *frame) = 0; - - void advanceWrite() { - mIntegerPhase -= mDenominator; - } - - void advanceRead() { - mIntegerPhase += mNumerator; - } - - /** - * Generate the filter coefficients in optimal order. - * - * Note that normalizedCutoff is ignored when upsampling, which is when - * the outputRate is higher than the inputRate. - * - * @param inputRate sample rate of the input stream - * @param outputRate sample rate of the output stream - * @param numRows number of rows in the array that contain a set of tap coefficients - * @param phaseIncrement how much to increment the phase between rows - * @param normalizedCutoff filter cutoff frequency normalized to Nyquist rate of output - */ - void generateCoefficients(int32_t inputRate, - int32_t outputRate, - int32_t numRows, - double phaseIncrement, - float normalizedCutoff); - - - int32_t getIntegerPhase() { - return mIntegerPhase; - } - - static constexpr int kMaxCoefficients = 8 * 1024; - std::vector<float> mCoefficients; - - const int mNumTaps; - int mCursor = 0; - std::vector<float> mX; // delayed input values for the FIR - std::vector<float> mSingleFrame; // one frame for temporary use - int32_t mIntegerPhase = 0; - int32_t mNumerator = 0; - int32_t mDenominator = 0; - - -private: - -#if MCR_USE_KAISER - KaiserWindow mKaiserWindow; -#else - HyperbolicCosineWindow mCoshWindow; -#endif - - static constexpr float kDefaultNormalizedCutoff = 0.70f; - - const int mChannelCount; -}; - -} /* namespace RESAMPLER_OUTER_NAMESPACE::resampler */ - -#endif //RESAMPLER_MULTICHANNEL_RESAMPLER_H |