Module processor 

Audio Processor Module

High-performance audio processing pipeline using Rayon for parallelization. Restored SoX VHQ Resampler and High-Order Noise Shaping for f64 Hi-Fi path.

Modules

Core Processors

• StreamingResampler and Resampler - SoX VHQ polyphase resampling
• Equalizer and BiquadSection - 10-band parametric IIR equalizer
• VolumeController and NoiseShaper - Volume control and noise shaping
• SpectrumAnalyzer - FFT spectrum analyzer
• FFTConvolver - FFT convolution for FIR filters
• LoudnessNormalizer, LoudnessMeter, and TruePeakDetector - EBU R128 loudness normalization
• DynamicLoudness - ISO 226 dynamic loudness compensation (Fletcher-Munson)
• Saturation - Tube/tape saturation for analog warmth
• Crossfeed - Bauer binaural crossfeed for headphones
• FirEq - FIR EQ with linear/minimum phase options

Unified Abstraction (Lock-Free Design)

• AudioProcessor and ProcessResult - shared processor trait/result types
• lockfree_params - lock-free parameter structures for thread-safe parameter passing
• adapters - processor adapters implementing AudioProcessor
• DspChain - composable DSP processing chain

Re-exports

pub use adapters::ConvolverProcessor;

pub use adapters::CrossfeedProcessor;

pub use adapters::DynamicLoudnessProcessor;

pub use adapters::EqProcessor;

pub use adapters::NoiseShaperProcessor;

pub use adapters::PeakLimiterProcessor;

pub use adapters::SaturationProcessor;

pub use adapters::VolumeProcessor;

pub use dsp_chain::DspChain;

pub use lockfree_params::AtomicCrossfeedParams;

pub use lockfree_params::AtomicDynamicLoudnessParams;

pub use lockfree_params::AtomicDynamicLoudnessTelemetry;

pub use lockfree_params::AtomicEqParams;

pub use lockfree_params::AtomicNoiseShaperParams;

pub use lockfree_params::AtomicPeakLimiterParams;

pub use lockfree_params::AtomicSaturationParams;

pub use lockfree_params::AtomicVolumeParams;

pub use lockfree_params::CrossfeedParamsSnapshot;

pub use lockfree_params::DynamicLoudnessParamsSnapshot;

pub use lockfree_params::EqParamsSnapshot;

pub use lockfree_params::NoiseShaperParamsSnapshot;

pub use lockfree_params::PeakLimiterParamsSnapshot;

pub use lockfree_params::SaturationParamsSnapshot;

pub use lockfree_params::SaturationTypeValue;

pub use lockfree_params::VolumeParamsSnapshot;

pub use lockfree_params::EQ_BANDS;

pub use traits::AudioProcessor;

pub use traits::ProcessResult;

Modules

adapters

Processor Adapters

dsp_chain

DSP Processing Chain

lockfree_params

Lock-free Parameter Structures

traits

Audio Processor Traits

Structs

AtomicDynamicLoudnessState

Thread-safe state for DynamicLoudness control from UI thread

AtomicLoudnessState

Atomic loudness state for lock-free audio thread access. Uses AtomicF64 with Relaxed ordering (gains don’t need strict synchronization).

AutomixAnalysis

AutomixAnalysisOptions

BiquadSection

IIR Biquad filter section (SOS - Second Order Section)

Crossfeed

Bauer crossfeed processor

CrossfeedSettings

Settings struct for API responses

DatabaseStats

Statistics about the loudness database

DynamicLoudness

Dynamic Loudness Compensation processor

Equalizer

10-band Parametric EQ

FFTConvolver

High-performance FFT convolver (Overlap-Save algorithm).

FirEq

FIR EQ generator: creates IR from band gain specifications

GainRamp

Linear gain ramp for smooth transitions between tracks. Caches the current gain and per-sample delta so accessors stay cheap.

LoudnessDatabase

SQLite database for track loudness metadata

LoudnessInfo

Loudness measurement information for API responses

LoudnessMeter

EBU R128 loudness meter using the ebur128 crate Measures integrated, short-term, momentary loudness and loudness range

LoudnessNormalizer

Loudness normalizer with EBU R128 compliance. Supports track-based pre-analysis and real-time streaming modes.

NoiseShaper

High-order noise shaping quantizer with SoX-verified coefficients

PeakLimiter

True Peak Limiter with look-ahead and proper release behavior.

ResampleOutput

Resampler

High-quality resampler using SoX (VHQ Polyphase implementation)

Saturation

Tube Saturation processor with configurable drive and mix

SaturationSettings

Settings struct for API responses

SpectrumAnalyzer

FFT-based spectrum analyzer for visualization

StreamingResampler

Stateful streaming resampler that maintains SoX instances across chunks. This is used by AudioPipeline for memory-efficient streaming resampling.

TrackLoudness

Loudness metadata for a single track

TruePeakDetector

True peak detector using 4x polyphase FIR oversampling.

VolumeController

Volume controller with anti-zipper smoothing

Enums

AutomixAnalysisMode

FirPhaseMode

Phase mode for FIR EQ

NoiseShaperCurve

Noise shaping curve presets All coefficients from SoX src/dither.c, NTF zeros verified |z| < 1

ResamplerError

Error type for resampler operations

SaturationType

Saturation type / character

Constants

CURRENT_SCAN_VERSION

Current scanner algorithm version Increment when measurement algorithm changes to trigger rescan

DEFAULT_BROADCAST_TARGET_LUFS

Default target loudness for broadcast (LUFS)

DEFAULT_STREAMING_TARGET_LUFS

Default target loudness for streaming (LUFS)

LOUDNESS_BANDS

ISO 226 inspired 7-band loudness compensation curve

STANDARD_BANDS

Standard 10-band EQ frequencies (ISO octave bands)

Functions

analyze_automix

analyze_automix_with_cancel

db_to_linear

Convert dB to linear gain. Shared across all processor modules.

linear_to_db

Convert linear gain to dB. Shared across all processor modules.