Module elements 

The elements: ESP-ADF’s filter/resample/mixer elements and ESP-SR’s lite front end, each an Element over interleaved i16.

Every element states its contract in its own docs and has a host test against a reference: byte-identity where the maths is exact (gain, channel ops, conversion, resampler), a stated tolerance against an external oracle where it is not (Biquad against ffmpeg and scipy, in rusty_esp_audio-esp’s oracle tests).

Structs

Agc

One gain per block, moved toward the target at the attack or release rate, applied in f32 with rounding and saturation.

AgcConfig

How the AGC behaves.

Biquad

A biquad section over up to MAX_CHANNELS channels of i16.

Coefficients

Normalised coefficients (a0 = 1).

Convert

Re-encode every sample to to (see codec::pcm::convert for the exact rules). Same-format input is a byte copy.

DcBlock

y[n] = x[n] - x[n-1] + r·y[n-1], per channel, in f32.

EnergyVad

The detector. Read is_speech after each block.

Gain

Multiply every sample by a fixed gain.

LinearResampler

Linear interpolation from in_rate to out_rate over up to MAX_CHANNELS channels of i16.

MonoToStereo

Duplicate a mono i16 stream onto two channels. Byte-exact.

StereoToMono

Average a stereo i16 stream to mono: (l + r) >> 1 (floor). Byte-exact.

VadConfig

How the detector decides.

Enums

BiquadKind

Which response to design.

Constants

MAX_CHANNELS

Channels the stateful filters keep memory for.

Functions

mix_i16

Sum two equal-length i16 byte streams into out, saturating. a, b and out must have the same even length.