Reference: Video Player Methods

NMVideoPlayer<T> implements IVideoPlayer<T>, which extends the kit’s IPlayer<VideoEventMap<T>>. Everything on IPlayer (play(), pause(), time(), volume(), queue(), addPlugin(), and the rest of transport, queue, volume, and plugin management) is unchanged kit surface, documented method by method across the Guided Tour rather than duplicated here. This page is the delta: everything that exists only because the medium is video.

Video element & geometry

Method	Signature	Notes
videoElement	readonly HTMLVideoElement | undefined	The raw element. undefined until the first backend() call.
backend()	() => IVideoBackend	The active backend instance, constructed lazily on first call. See Adapter: Video Backend.
backend(kind)	(kind: VideoBackendKind) => Promise<void>	Swaps the active backend at runtime, disposing the current instance and emitting 'backend:changed'. Only 'html5' has a built-in implementation, 'mse' and 'webcodecs' need options.backendFactory to supply one, otherwise the swap rejects with core:not-implemented/video-backend.
videoRect()	() => VideoRect | null	The displayed content rectangle under object-fit: contain, null before metadata loads. Changes fire 'videoRect'.

Fullscreen, PiP, theater

Method	Signature	Notes
fullscreen() / fullscreen(state)	() => FullscreenState, (state: FullscreenState | boolean) => void	Throws core:policy/fullscreenUnsupported with no platform fullscreen controller configured.
pip() / pip(state)	() => PipState, (state: PipState | boolean) => void	Throws core:policy/pipUnsupported with no platform PiP controller.
theater() / theater(state)	() => TheaterState, (state: TheaterState | boolean) => void	Pure UI-layout state, no browser API behind it.
subtitleState()	() => SubtitleState	Whether any subtitle track is active, checks subtitle() first, falls back to scanning native textTracks.
toggleFullscreen() / togglePip() / toggleTheater()	() => void	Flip the matching state.

Aspect ratio

Method	Signature	Notes
aspectRatio() / aspectRatio(value)	() => Stretching, (value: Stretching) => void	'uniform' (contain, default) / 'fill' / 'exactfit' (cover) / 'none'.
cycleAspectRatio()	() => void	Steps through ['uniform', 'fill', 'exactfit', 'none'] in order.

Track selection

Method	Signature	Notes
subtitles()	() => SubtitleTrack[]	Track list for the active item.
subtitle() / subtitle(idx)	() => CurrentSubtitleSelection | null, (idx: number | null) => Promise<void>	null selects off.
cycleSubtitles()	() => void	Walks off -> 0 -> ... -> N-1 -> off.
subtitleStyle() / subtitleStyle(patch)	() => SubtitleStyle, (patch: Partial<SubtitleStyle>) => void	In-memory only, persistence is a consumer concern, see Adapter: Subtitle Style Store.
audioTracks()	() => AudioTrack[]	Embedded audio rendition list.
audioTrack() / audioTrack(idx)	() => CurrentAudioTrackSelection | null, (idx: number) => Promise<void>
cycleAudioTracks()	() => void	Wraps around the list.
qualityLevels() / qualityLevels({ includeUnsupported: true })	() => QualityLevel[]	Populated once 'levels' fires.
quality() / quality(idx)	() => CurrentQualitySelection | 'auto', (idx: number | 'auto') => void	Setting a level also emits 'quality:requested' immediately, before 'level-switched' confirms.

chapters(), chapter() / chapter(idx), seekToChapter(idx, opts?), nextChapter(opts?), and previousChapter(opts?) are shared IPlayer surface, not a video addition, nomercy-music-player has the same chapter methods for podcast-style chapter markers. They’re covered on the Guided Tour: Chapters rather than repeated here.

Segment / window playback

Method	Signature	Notes
playSegment(opts)	(opts: SegmentOptions) => void	Seeks to startSec, watches for endSec, applies onEnd ('loop' / 'hold' / 'advance'). Always emits 'segmentBoundary' at the boundary. Replaces any previously active window immediately.
clearSegment()	() => void	Stops watching without seeking or pausing. No-op with nothing active.

Generic enough for intro loops, chapter-range playback, or a disc-menu’s skipToMark equivalent, none of which are disc-specific in the primitive itself.

Playback re-declarations

IVideoPlayer re-declares a handful of methods that already belong to the shared player surface, so they read next to the video-specific methods for doc locality rather than adding anything new: time(), duration(), playbackRate(), togglePlayback(), toggleMute(), rewind(), forward(), playState(), volumeState(), volume(), buffered(), play(), pause(), stop(), next(), previous(), item(), queueLength(), index(), queue(), playbackRates(). They are already required on IPlayer (with item() supplied by the shared WithCurrentItem capability), so the re-declarations are redundant; the item-bearing ones re-type their playlist values with the concrete video item type T. Signatures and behavior are unchanged from IPlayer, see the Guided Tour.

Coming from v1

Method names that were removed or renamed in v2 are not part of the IVideoPlayer surface above. To move a v1 app across without rewriting every call at once, see Migrating from v1.

Next steps

• Reference: VideoPlayerConfig: the setup(config) fields specific to video, on top of the kit’s shared config.
• Reference: Metrics, Clock & Accessibility: metrics(), now(), announce(), and the bandwidth() / canPlay() pair Quality Levels already walks through in a video context, shared kit surface not re-declared on IVideoPlayer.