Struct Quality 

pub struct Quality {
    pub loss: f64,
    pub cumulative_lost: i64,
    pub jitter: Duration,
    pub round_trip: Option<Duration>,
    pub mos: f64,
}

How a call is going.

Fields

loss: f64

Loss since the last report, as a fraction between 0 and 1.

cumulative_lost: i64

Packets lost since the stream began. Signed, because duplicates can make it go down.

jitter: Duration

Interarrival jitter (RFC 3550 §6.4.1).

round_trip: Option<Duration>

The most recent round-trip time, if a report has come back with one.

mos: f64

An estimated mean opinion score. See Quality::mos for what it is and is not.

Implementations

impl Quality

pub fn mos(loss: f64, jitter: Duration, round_trip: Option<Duration>) -> f64

Estimate a mean opinion score from loss, jitter and round-trip time.

This is an estimate, not a measurement. A real MOS comes from people listening. What this computes is the ITU-T G.107 E-model’s transmission rating R, converted to a score by G.107’s own formula, from impairment terms that are the common simplification rather than the full model: delay is folded into one term, and loss is charged at a flat rate that is roughly right for G.711 and wrong for a codec with packet loss concealment.

It is worth having anyway, because it collapses three numbers that trade against each other into one that can be compared between calls. It is not worth reporting to four decimal places, and sipx does not.

pub fn score_from_rating(rating: f64) -> f64

G.107’s own conversion from the transmission rating R to a score.

Exact, unlike the impairment terms feeding it: this part is the standard’s formula.

Trait Implementations

impl Clone for Quality

fn clone(&self) -> Quality

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Quality

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

Formats the value using the given formatter.

impl PartialEq for Quality

fn eq(&self, other: &Quality) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for Quality

impl StructuralPartialEq for Quality