VideoTrackGenerator.md

VideoTrackGenerator

Namespace: SpawnDev.SpawnJS.JSObjects
Inherits: SpawnJSObject
Source: JSObjects/VideoTrackGenerator.cs
MDN Reference: VideoTrackGenerator on MDN

The VideoTrackGenerator interface of the Insertable Streams for MediaStreamTrack API has a WritableStream property that acts as a MediaStreamTrack source, by consuming a stream of VideoFrames as input. https://developer.mozilla.org/en-US/docs/Web/API/VideoTrackGenerator

Constructors

Signature	Description
VideoTrackGenerator()	The VideoTrackGenerator() constructor creates a new VideoTrackGenerator object which consumes a stream of media frames and exposes a MediaStreamTrack.

Properties

Property	Type	Access	Description
Muted	bool	get	A Boolean property to temporarily halt or resume the generation of video frames in the output track.
MediaStreamTrack	MediaStreamTrack	get	The output MediaStreamTrack.
Writable	WritableStream	get	The input WritableStream.

Examples

SpawnDev.SpawnJS Mapping Note: The JavaScript examples below show the standard Web API usage. In SpawnDev.SpawnJS, the same API is available with C# conventions:

• Properties and methods use PascalCase (e.g., readyState becomes ReadyState)
• Events use ActionEvent with +=/-= (e.g., addEventListener("click", fn) becomes OnClick += handler)
• Async methods return Task<T> instead of Promise<T>
• Objects should be disposed with using statements
• Access via JS.Get<VideoTrackGenerator>(...) or constructor new VideoTrackGenerator(...)

const stream = await navigator.mediaDevices.getUserMedia({ video: true });
const [track] = stream.getVideoTracks();
const worker = new Worker("worker.js");
worker.postMessage({ track }, [track]);
const { data } = await new Promise((r) => {
  worker.onmessage = r;
});
video.srcObject = new MediaStream([data.track]);

onmessage = async ({ data: { track } }) => {
  const vtg = new VideoTrackGenerator();
  self.postMessage({ track: vtg.track }, [vtg.track]);
  const { readable } = new MediaStreamTrackProcessor({ track });
  await readable
    .pipeThrough(new TransformStream({ transform }))
    .pipeTo(vtg.writable);
};

See full example on MDN