Crate alpha2_audio 

Platform-independent, real-time-safe audio DSP primitives and graph.

Structs

AudioGraph

Clip chain -> track bus -> master bus graph with deterministic latency aggregation.

AudioGraphState

Complete graph history captured between offline chunks.

AutomatedGain

Sample-accurate gain driven by an immutable automation curve.

AutomationCurve

Immutable piecewise-linear automation prepared off the realtime thread.

AutomationPoint

One sample-addressed automation point.

Biquad

Two-channel transposed-direct-form-II biquad.

ChainStateError

Where and why a ProcessorChain refused a saved state. The chain is unchanged.

Compressor

Linked-channel compressor with deterministic lookahead and soft attack/release.

Ducker

Sidechain ducker. Inputs are program channels followed by matching sidechain channels.

EnvelopeFollower

Reusable peak envelope follower.

EqualPowerCrossfade

Equal-power crossfade between two planar input buses.

Gain

Stateless linear amplitude multiplier.

Interpolator

Band-limited interpolation for clips at non-unity speed, using the same kernel as Resampler at any real source position.

LinearFade

Sample-addressed linear fade independent of host block size.

LoudnessMeter

A streaming BS.1770-4 / EBU R128 loudness meter.

LoudnessNormalization

A static gain to a loudness target, bounded by a true-peak ceiling and any master limiter.

LoudnessReport

What a LoudnessMeter has measured.

PeakLimiter

Linked-channel peak limiter with instantaneous attack and exponential release.

ProcessCtx

Immutable information for one DSP invocation.

ProcessorChain

Ordered processor chain with all realtime scratch allocated by prepare.

ResampleError

Why a converter could not be made.

Resampler

A band-limited converter from one sample rate to another.

SchroederReverb

Allocation-free prepared Schroeder reverb with four combs and two allpasses.

StateBlob

Opaque processor state saved outside the real-time process path.

Stretch

WSOLA’s grid at one sample rate.

StretchReader

A Stretch that caches the last segments’ offsets, so sequential reads search each once.

StretchSignal

samples from index start; silent elsewhere and wherever a sample is not finite.

Waveform

A finished waveform summary: its levels, finest first.

WaveformBucket

The extremes and RMS of one run of samples of one channel.

WaveformLevel

One zoom level of a Waveform.

WaveformSummary

Builds a Waveform from planar samples streamed in blocks.

Enums

BiquadKind

Common parametric equalizer shapes.

ChainError

Why a ProcessorChain refuses a processor.

ChannelLayout

Validated channel organization used at every host boundary.

FadeDirection

Direction of a linear amplitude fade.

GraphStateError

Where and why an AudioGraph refused a saved state. The graph is unchanged.

LoudnessError

Why a meter cannot be configured or fed.

StateError

Why a processor, crate::ProcessorChain or crate::AudioGraph refuses a saved state. A refused state changes nothing.

TransportState

Current host transport state supplied without consulting a platform clock.

WaveformError

Why a waveform summary cannot be configured or fed.

Constants

ABSOLUTE_GATE_LUFS

The level below which a block never counts, in LUFS.

LIMITER_MARGIN_DB

Headroom in dB below a master limiter’s threshold for a normalized mix’s sample peak, so the limiter never acts. It covers f32 gain rounding (about 2e-6 dB) a thousand times over.

MAX_DOWNSAMPLE_FACTOR

The largest source-to-target rate ratio. Downsampling widens the filter by 16 taps a side per factor, and beyond this it would not fit the table (768 kHz converts down to 94 Hz).

MAX_FILTERED_SPEED

The fastest speed whose filter narrows with it. Faster clips keep this filter, bounding an output sample to 2 * HALF_TAPS * MAX_FILTERED_SPEED source samples.

MAX_FREQUENCY_FRACTION

Highest frequency a filter renders, as a fraction of the sample rate.

MAX_PEAKING_GAIN_DB

Largest peaking gain a filter renders, in decibels either way.

MAX_RATIO

Largest ratio a compressor renders.

MAX_RESAMPLE_RATE

The highest rate either side may have.

MAX_WAVEFORM_LEVELS

Most zoom levels; a 1-sample base reaches 4^15 samples, over six hours at 48 kHz.

MIN_FREQUENCY_HZ

Lowest frequency a filter renders, in hertz.

Q_RANGE

The resonances a filter renders.

STRETCH_SEGMENT_GRAINS

Grains whose offsets one chain decides.

STRETCH_WARMUP_GRAINS

Grains a segment’s chain runs before its first, from offset zero.

Traits

Processor

Stateful DSP unit whose process method performs no allocation or locking.