Struct Kalman 

pub struct Kalman { /* private fields */ }

Kalman filter over the one-way delay gradient, per draft-ietf-rmcat-gcc-02 §5.3.

What it is for

A single inter-group delay measurement is mostly noise: scheduling jitter at either end, the receiver’s clock resolution, and TWCC’s 250 µs quantisation all move it around by more than the signal does early on. The filter estimates the trend — is the queue growing, and how fast — while adapting how much it trusts each new measurement to how noisy the measurements have been.

Pure

No clock, no allocation, no state beyond four numbers. Every input is a parameter, which is what lets upstream’s table-driven vectors port directly.

Implementations

impl Kalman

pub fn new() -> Self

A filter with the draft’s default tuning.

pub fn with_process_noise(self, process_noise: f64) -> Self

How fast the underlying gradient is assumed to drift. Larger tracks faster and is noisier.

pub fn estimate(&self) -> f64

The current trend estimate, in milliseconds per group.

pub fn update(&mut self, measurement: f64) -> f64

Fold in one inter-group delay measurement and return the updated estimate.

measurement is arrival spread minus departure spread for a pair of groups, in milliseconds.

Trait Implementations

impl Clone for Kalman

fn clone(&self) -> Kalman

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Kalman

impl Debug for Kalman

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Kalman

fn default() -> Self

Returns the “default value” for a type.