Crate audio_resample_bsd 

RT-safe audio resampling (rubato-based).

This crate defines the resampling layer — the Resampler trait is the only processing interface that may be called directly from the real-time (RT) audio thread. Codecs, DSP primitives, and graph nodes all perform sample-rate conversion through this trait.

Data layout — planar flat

Input and output are flat &[f32] buffers in planar layout: [ch0_frames..., ch1_frames...]. This matches the layout of audio_core_bsd::AudioFrame::samples, so an AudioFrame can be passed to a Resampler directly with no extra copy or rearrangement. The channel count is fixed when the implementation is constructed.

Real-time safety boundary — CRITICAL

Only Resampler::process_into_buffer may be called from the RT thread. On this path, heap allocation / locking / panicking / system calls are all forbidden (same principle as the audio-core-bsd AudioNode RT contract). Every buffer must be pre-allocated when the implementation is constructed.

Resampler::set_rate rebuilds the inner resampler to change the ratio and therefore allocates. It must be called only from a configuration/worker thread — never the RT thread, and only between audio cycles. The RT-alloc=0 guarantee applies only to process_into_buffer (the fixed-ratio path).

Implementation status (0.2.0)

This crate provides the public API (Resampler trait / ResampleError) and the rubato 4.0-backed standard implementation RubatoResampler. RubatoResampler implements a zero-copy, allocation-free RT processing path at a fixed input ratio (FixedSync::Input).

Re-exports

pub use error::ResampleError;

pub use error::Result;

pub use resampler::Resampler;

pub use rubato_impl::RubatoResampler;

Modules

error

Resampling error types and the Result alias.

resampler

Public resampling interface — the RT-safe processing boundary of this crate.

rubato_impl

RT-safe Resampler standard implementation backed by the rubato Fft synchronous resampler.