144 lines
6.6 KiB
C++
144 lines
6.6 KiB
C++
/*
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==============================================================================
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This file is part of the JUCE library.
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Copyright (c) 2017 - ROLI Ltd.
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JUCE is an open source library subject to commercial or open-source
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licensing.
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The code included in this file is provided under the terms of the ISC license
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http://www.isc.org/downloads/software-support-policy/isc-license. Permission
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To use, copy, modify, and/or distribute this software for any purpose with or
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without fee is hereby granted provided that the above copyright notice and
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this permission notice appear in all copies.
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JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
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EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
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DISCLAIMED.
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==============================================================================
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*/
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namespace juce
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{
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/**
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Interpolator for resampling a stream of floats using 4-point lagrange interpolation.
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Note that the resampler is stateful, so when there's a break in the continuity
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of the input stream you're feeding it, you should call reset() before feeding
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it any new data. And like with any other stateful filter, if you're resampling
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multiple channels, make sure each one uses its own LagrangeInterpolator
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object.
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@see CatmullRomInterpolator
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@tags{Audio}
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*/
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class JUCE_API LagrangeInterpolator
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{
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public:
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LagrangeInterpolator() noexcept;
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~LagrangeInterpolator() noexcept;
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/** Resets the state of the interpolator.
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Call this when there's a break in the continuity of the input data stream.
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*/
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void reset() noexcept;
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/** Resamples a stream of samples.
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@param speedRatio the number of input samples to use for each output sample
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@param inputSamples the source data to read from. This must contain at
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least (speedRatio * numOutputSamplesToProduce) samples.
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@param outputSamples the buffer to write the results into
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@param numOutputSamplesToProduce the number of output samples that should be created
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@returns the actual number of input samples that were used
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*/
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int process (double speedRatio,
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const float* inputSamples,
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float* outputSamples,
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int numOutputSamplesToProduce) noexcept;
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/** Resamples a stream of samples.
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@param speedRatio the number of input samples to use for each output sample
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@param inputSamples the source data to read from. This must contain at
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least (speedRatio * numOutputSamplesToProduce) samples.
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@param outputSamples the buffer to write the results into
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@param numOutputSamplesToProduce the number of output samples that should be created
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@param available the number of available input samples. If it needs more samples
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than available, it either wraps back for wrapAround samples, or
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it feeds zeroes
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@param wrapAround if the stream exceeds available samples, it wraps back for
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wrapAround samples. If wrapAround is set to 0, it will feed zeroes.
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@returns the actual number of input samples that were used
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*/
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int process (double speedRatio,
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const float* inputSamples,
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float* outputSamples,
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int numOutputSamplesToProduce,
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int available,
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int wrapAround) noexcept;
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/** Resamples a stream of samples, adding the results to the output data
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with a gain.
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@param speedRatio the number of input samples to use for each output sample
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@param inputSamples the source data to read from. This must contain at
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least (speedRatio * numOutputSamplesToProduce) samples.
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@param outputSamples the buffer to write the results to - the result values will be added
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to any pre-existing data in this buffer after being multiplied by
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the gain factor
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@param numOutputSamplesToProduce the number of output samples that should be created
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@param gain a gain factor to multiply the resulting samples by before
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adding them to the destination buffer
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@returns the actual number of input samples that were used
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*/
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int processAdding (double speedRatio,
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const float* inputSamples,
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float* outputSamples,
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int numOutputSamplesToProduce,
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float gain) noexcept;
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/** Resamples a stream of samples, adding the results to the output data
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with a gain.
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@param speedRatio the number of input samples to use for each output sample
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@param inputSamples the source data to read from. This must contain at
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least (speedRatio * numOutputSamplesToProduce) samples.
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@param outputSamples the buffer to write the results to - the result values will be added
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to any pre-existing data in this buffer after being multiplied by
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the gain factor
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@param numOutputSamplesToProduce the number of output samples that should be created
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@param available the number of available input samples. If it needs more samples
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than available, it either wraps back for wrapAround samples, or
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it feeds zeroes
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@param wrapAround if the stream exceeds available samples, it wraps back for
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wrapAround samples. If wrapAround is set to 0, it will feed zeroes.
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@param gain a gain factor to multiply the resulting samples by before
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adding them to the destination buffer
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@returns the actual number of input samples that were used
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*/
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int processAdding (double speedRatio,
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const float* inputSamples,
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float* outputSamples,
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int numOutputSamplesToProduce,
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int available,
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int wrapAround,
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float gain) noexcept;
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private:
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float lastInputSamples[5];
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double subSamplePos;
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JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (LagrangeInterpolator)
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};
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} // namespace juce
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