silence.h

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#pragma once
 
#include "fl/audio/audio_detector.h"
#include "fl/stl/function.h"
#include "fl/stl/vector.h"
#include "fl/stl/noexcept.h"
 
namespace fl {
namespace audio {
namespace detector {
 
class Silence : public Detector {
public:
    Silence() FL_NOEXCEPT;
    ~Silence() FL_NOEXCEPT override;
 
    void update(shared_ptr<Context> context) override;
    void fireCallbacks() override;
    bool needsFFT() const override { return false; }  // Uses RMS from Sample
    const char* getName() const override { return "Silence"; }
    void reset() override;
 
    // Callbacks (multiple listeners supported)
    function_list<void(u8 silent)> onSilence;
    function_list<void()> onSilenceStart;
    function_list<void()> onSilenceEnd;
    function_list<void(u32 durationMs)> onSilenceDuration;
 
    // State access
    bool isSilent() const { return mIsSilent; }
    u32 getSilenceDuration() const;
    float getSilenceThreshold() const { return mSilenceThreshold; }
    float getCurrentRMS() const { return mCurrentRMS; }
 
    // Configuration
    void setSilenceThreshold(float threshold) { mSilenceThreshold = threshold; }
    void setMinSilenceDuration(u32 durationMs) { mMinSilenceDuration = durationMs; }
    void setMaxSilenceDuration(u32 durationMs) { mMaxSilenceDuration = durationMs; }
    void setHysteresis(float hysteresis) { mHysteresis = hysteresis; }
 
private:
    bool mIsSilent;
    bool mPreviousSilent;
    float mCurrentRMS;
    float mSilenceThreshold;
    float mHysteresis;
 
    u32 mSilenceStartTime;
    u32 mSilenceEndTime;
    u32 mMinSilenceDuration;
    u32 mMaxSilenceDuration;
    u32 mLastUpdateTime;
 
    // History for smoothing
    vector<float> mRMSHistory;
    int mHistorySize;
    int mHistoryIndex;
 
    enum class PendingSilenceEvent : u8 { kNone, kStart, kEnd, kMaxDuration };
    PendingSilenceEvent mPendingEvent = PendingSilenceEvent::kNone;
    u32 mPendingDuration = 0;
 
    static constexpr u32 DEFAULT_MIN_SILENCE_MS = 500;
    static constexpr u32 DEFAULT_MAX_SILENCE_MS = 60000;  // 1 minute
    static constexpr float DEFAULT_SILENCE_THRESHOLD = 0.01f;
    static constexpr float DEFAULT_HYSTERESIS = 0.2f;
    static constexpr int DEFAULT_HISTORY_SIZE = 5;
 
    float getSmoothedRMS();
    bool checkSilenceCondition(float smoothedRMS);
};
 
} // namespace detector
} // namespace audio
} // namespace fl