Struct Capabilities 

pub struct Capabilities {
    pub video: bool,
    pub audio_settings: bool,
    pub subtitle_switching: bool,
    pub audio_track_switching: bool,
    pub seeks_transcoded_in_place: bool,
}

What an engine can do, so callers adapt without naming engines.

If a caller ever branches on which engine it holds, this struct is missing something — add it here rather than sniffing. Engine identity leaking into callers is the coupling DR-238 came from.

Fields

video: bool

The engine renders pictures, not only sound.

audio_settings: bool

Audio settings (EQ, normalisation, gapless) are honoured.

subtitle_switching: bool

Subtitle tracks can be selected without re-opening.

audio_track_switching: bool

Audio tracks can be selected without re-opening.

seeks_transcoded_in_place: bool

A server-side transcode can be seeked without re-opening the stream.

True for hls.js, which seeks within the VOD playlist it is handed and lets the server catch up. False for mpv, whose HLS demuxer cannot make the server transcode from a new offset.

Declared by the engine rather than inferred by the caller. The previous design decided this from is_hls and use_html5 in a command handler — on behalf of engines it did not own — which is how “who renders” came to mean “how do I seek” and why a transcoded seek silently did nothing the moment native video changed the renderer (DR-238).

Re-negotiating a stream needs the repository, which sits above the engine, so the engine states the capability and the caller acts on it.

Implementations

impl Capabilities

pub fn mpv() -> Self

mpv.

Cannot seek a server-side transcode in place: its HLS demuxer will not make the server produce segments from a new offset, so the stream has to be re-opened.

pub fn exoplayer() -> Self

ExoPlayer.

Can seek a transcode in place. It is a full HLS client, so like hls.js it seeks within the VOD playlist it was handed and lets the server catch up. Grouping it with mpv as “a native engine” gets this exactly backwards — being native is not the property that matters here, speaking HLS is, and that is the whole reason this is declared per engine rather than inferred from a category.

pub fn webview() -> Self

An engine that renders through the webview element, where hls.js seeks within the playlist it was handed.

Trait Implementations

impl Clone for Capabilities

fn clone(&self) -> Capabilities

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Capabilities

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

Formats the value using the given formatter.

impl PartialEq for Capabilities

fn eq(&self, other: &Capabilities) -> 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 Capabilities

impl Eq for Capabilities

impl StructuralPartialEq for Capabilities