fl::audio::SignalConditioner Class Reference

Detailed Description

SignalConditioner performs low-level audio preprocessing to clean raw PCM samples before FFT analysis or beat detection.

Pipeline stages:

1. Spike filtering - Rejects I2S glitches (samples beyond threshold)
2. DC offset removal - Subtracts running average to center signal at zero
3. Noise gate - Applies hysteresis gating to suppress background noise

Usage:

SignalConditioner conditioner;
SignalConditionerConfig config;
config.spikeThreshold = 10000;
config.noiseGateOpenThreshold = 500;
conditioner.configure(config);
 
Sample rawSample = ...;  // From I2S microphone
Sample cleanSample = conditioner.processSample(rawSample);

Definition at line 54 of file signal_conditioner.h.

#include <signal_conditioner.h>

Collaboration diagram for fl::audio::SignalConditioner:

Classes
struct	Stats
	Get current statistics (for debugging/monitoring) More...

Public Member Functions
	SignalConditioner () FL_NOEXCEPT
	SignalConditioner (const SignalConditionerConfig &config) FL_NOEXCEPT
	~SignalConditioner () FL_NOEXCEPT
void	configure (const SignalConditionerConfig &config) FL_NOEXCEPT
	Configure the signal conditioner.
const Stats &	getStats () const FL_NOEXCEPT
Sample	processSample (const Sample &sample) FL_NOEXCEPT
	Process a raw audio sample through the conditioning pipeline.
void	reset () FL_NOEXCEPT
	Reset internal state (DC estimate, noise gate state)

Private Member Functions
void	applyNoiseGate (span< const i16 > pcm, vector< i16 > &output) FL_NOEXCEPT
	Apply noise gate with hysteresis.
i32	calculateDCOffset (span< const i16 > pcm, const vector< bool > &validMask) FL_NOEXCEPT
	Calculate DC offset from valid samples only.
size	filterSpikes (span< const i16 > pcm, vector< bool > &validMask) FL_NOEXCEPT
	Detect and reject spike samples.
void	removeDCOffset (span< const i16 > pcm, i32 dcOffset, vector< i16 > &output) FL_NOEXCEPT
	Remove DC offset from samples.

Private Attributes
SignalConditionerConfig	mConfig
bool	mNoiseGateOpen = false
	Noise gate state.
vector< i16 >	mOutputBuffer
Stats	mStats
vector< i16 >	mTempBuffer
vector< bool >	mValidMask
	Working buffers (reused to avoid allocations)

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The documentation for this class was generated from the following files:

• fl/audio/signal_conditioner.h
• fl/audio/signal_conditioner.cpp.hpp