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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*!********************************************************************
Audacity: A Digital Audio Editor
CompressorProcessor.h
Matthieu Hodgkinson
**********************************************************************/
#pragma once
#include "DynamicRangeProcessorTypes.h"
#include <array>
#include <limits>
#include <memory>
#include <vector>
namespace DanielRudrich
{
class GainReductionComputer;
class LookAheadGainReduction;
} // namespace DanielRudrich
class DYNAMIC_RANGE_PROCESSOR_API CompressorProcessor
{
public:
struct FrameStats
{
float maxInputSampleDb = -std::numeric_limits<float>::infinity();
float dbGainOfMaxInputSample = 0;
};
static float
GetMaxCompressionDb(const DynamicRangeProcessorSettings& settings);
static float GetMakeupGainDb(const DynamicRangeProcessorSettings& settings);
static float EvaluateTransferFunction(
const DynamicRangeProcessorSettings& settings, float inputDb);
CompressorProcessor(
const DynamicRangeProcessorSettings& settings = {
// No reason to initialize with compressor settings other than
// convenience.
CompressorSettings {} });
CompressorProcessor(const CompressorProcessor& other) = delete;
~CompressorProcessor();
void ApplySettingsIfNeeded(const DynamicRangeProcessorSettings& settings);
void Init(int sampleRate, int numChannels, int blockSize);
void Reinit();
const DynamicRangeProcessorSettings& GetSettings() const;
void
Process(const float* const* inBlock, float* const* outBlock, int blockLen);
const std::vector<std::vector<float>>& GetDelayedInput() const;
const FrameStats& GetLastFrameStats() const;
float EvaluateTransferFunction(float inputDb) const;
private:
void UpdateEnvelope(const float* const* inBlock, int blockLen);
void CopyWithDelay(const float* const* inBlock, int blockLen);
void ApplyEnvelope(
float* const* outBlock, int blockLen, float& delayedInputMax,
int& delayedInputMaxIndex);
bool Initialized() const;
static constexpr auto maxBlockSize = 512;
const std::unique_ptr<DanielRudrich::GainReductionComputer>
mGainReductionComputer;
const std::unique_ptr<DanielRudrich::LookAheadGainReduction>
mLookAheadGainReduction;
DynamicRangeProcessorSettings mSettings;
int mSampleRate = 0;
int mNumChannels = 0;
int mBlockSize = 0;
std::array<float, maxBlockSize> mEnvelope;
std::vector<std::vector<float>>
mDelayedInput; // Can't conveniently use an array here, because neither
// delay time nor sample rate are known at compile time.
// Re-allocation during playback is only done if the user
// changes the look-ahead settings, in which case glitches
// are hardly avoidable anyway.
FrameStats mLastFrameStats;
};
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