paulxstretch/deps/juce/modules/juce_dsp/widgets/juce_Limiter.h

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/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2020 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
By using JUCE, you agree to the terms of both the JUCE 6 End-User License
Agreement and JUCE Privacy Policy (both effective as of the 16th June 2020).
End User License Agreement: www.juce.com/juce-6-licence
Privacy Policy: www.juce.com/juce-privacy-policy
Or: You may also use this code under the terms of the GPL v3 (see
www.gnu.org/licenses).
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
namespace dsp
{
/**
A simple limiter with standard threshold and release time controls, featuring
two compressors and a hard clipper at 0 dB.
@tags{DSP}
*/
template <typename SampleType>
class Limiter
{
public:
//==============================================================================
/** Constructor. */
Limiter() = default;
//==============================================================================
/** Sets the threshold in dB of the limiter.*/
void setThreshold (SampleType newThreshold);
/** Sets the release time in milliseconds of the limiter.*/
void setRelease (SampleType newRelease);
//==============================================================================
/** Initialises the processor. */
void prepare (const ProcessSpec& spec);
/** Resets the internal state variables of the processor. */
void reset();
//==============================================================================
/** Processes the input and output samples supplied in the processing context. */
template <typename ProcessContext>
void process (const ProcessContext& context) noexcept
{
const auto& inputBlock = context.getInputBlock();
auto& outputBlock = context.getOutputBlock();
const auto numChannels = outputBlock.getNumChannels();
const auto numSamples = outputBlock.getNumSamples();
jassert (inputBlock.getNumChannels() == numChannels);
jassert (inputBlock.getNumSamples() == numSamples);
if (context.isBypassed)
{
outputBlock.copyFrom (inputBlock);
return;
}
firstStageCompressor.process (context);
auto secondContext = ProcessContextReplacing<SampleType> (outputBlock);
secondStageCompressor.process (secondContext);
outputBlock.multiplyBy (outputVolume);
for (size_t channel = 0; channel < numChannels; ++channel)
{
FloatVectorOperations::clip (outputBlock.getChannelPointer (channel), outputBlock.getChannelPointer (channel),
(SampleType) -1.0, (SampleType) 1.0, (int) numSamples);
}
}
private:
//==============================================================================
void update();
//==============================================================================
Compressor<SampleType> firstStageCompressor, secondStageCompressor;
SmoothedValue<SampleType, ValueSmoothingTypes::Linear> outputVolume;
double sampleRate = 44100.0;
SampleType thresholddB = -10.0, releaseTime = 100.0;
};
} // namespace dsp
} // namespace juce