Crate embedded_audio 

Duty-modulated PWM audio for embedded targets: effect banks, tiered DSP, mixing.

Quick start

use embedded_audio::prelude::*;

let bank = SoundBank::parse(FLASH_BLOB)?;
let mut engine = AudioEngine::new(AudioConfig::default_duty());
engine.set_bank(bank);
engine.play(1, AdsrSpec::click())?;

// In a timer ISR at `config.sample_rate_hz`:
let duty = engine.tick();

Tiers

Tier	Source	Use
A	Tone / wavetable / FM synth	UI beeps, alarms
B	PCM8 / IMA ADPCM in flash	Sampled SFX
C	Packed ΣΔ bitstream	Premium short sounds

Build banks on the host with the eaf-bake tool (std feature).

Procedural extras

Standalone building blocks, composed manually rather than driven through the bank format: pluck::KarplusPluck (Karplus-Strong string) and fx (Overdrive, Wavefolder, Tremolo) need no extra feature; [drums] (AnalogBassDrum, AnalogSnareDrum, HiHat) and [dsp] need the dsp feature.

Re-exports

pub use bank::BANK_BUILD_CAP;

pub use bank::BANK_MAGIC;

pub use bank::BANK_VERSION;

pub use bank::BankBuilder;

pub use bank::EffectEntry;

pub use bank::SoundBank;

pub use config::AudioConfig;

pub use config::DEFAULT_PWM_CARRIER_HZ;

pub use config::DEFAULT_PWM_PERIOD;

pub use config::DEFAULT_SAMPLE_RATE_HZ;

pub use config::crossfade_step_q8;

pub use decode::AdpcmDecoder;

pub use decode::AdpcmStream;

pub use decode::Pcm8Stream;

pub use engine::AudioEngine;

pub use engine::VoiceStealingPolicy;

pub use envelope::Adsr;

pub use envelope::AdsrSpec;

pub use error::AudioError;

pub use fixed::db_to_q8;

pub use fixed::q8_to_db;

pub use fx::Overdrive;

pub use fx::Tremolo;

pub use fx::Wavefolder;

pub use hal::DmaDoubleBuffer;

pub use hal::DutyBuffer;

pub use hal::PwmDutySink;

pub use hal::fill_buffer_into;

pub use hal::fill_dma_half_buffers;

pub use hal::tick_into;

pub use output::DutyMode;

pub use output::PwmMapper;

pub use output::SigmaDelta;

pub use output::SigmaDelta2ndOrder;

pub use output::pcm_to_dac_u8;

pub use output::pcm_to_dac_u12;

pub use output::pcm_to_dac_u16;

pub use output::pcm_to_i16;

pub use output::pcm_to_i32;

pub use pluck::KarplusPluck;

pub use source::VoiceSource;

pub use stream::SigmaDeltaBitStream;

pub use synth::FmVoice;

pub use synth::PULSE_25_TABLE;

pub use synth::SAW_TABLE;

pub use synth::SINE_TABLE;

pub use synth::SQUARE_TABLE;

pub use synth::TRIANGLE_TABLE;

pub use synth::ToneParams;

pub use synth::ToneVoice;

pub use synth::Waveform;

pub use synth::WavetableVoice;

pub use synth::generate_wavetable_fixed;

pub use tier::EffectKind;

pub use tier::flags;

Modules

bank

config

decode

engine

envelope

error

fixed

fx

Lightweight per-sample effects ported from DaisySP’s Effects module: waveshaping distortion, wavefolding, and tremolo. All three run on i8 PCM with plain arithmetic (no libm/std), so they’re part of the always-on core rather than the dsp feature.

hal

output

pluck

Karplus-Strong plucked-string synthesis.

prelude

source

stream

synth

tier

voice