MediaStreamTrackGenerator.md

MediaStreamTrackGenerator

Namespace: SpawnDev.SpawnJS.JSObjects
Inherits: MediaStreamTrack
Source: JSObjects/MediaStreamTrackGenerator.cs
MDN Reference: MediaStreamTrackGenerator on MDN

The MediaStreamTrackGenerator interface of the Insertable Streams for MediaStreamTrack API creates a WritableStream that acts as a MediaStreamTrack source. The object consumes a stream of media frames as input, which can be audio or video frames. https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrackGenerator

Constructors

Signature	Description
MediaStreamTrackGenerator(MediaStreamTrackGeneratorOptions options)	The MediaStreamTrackGenerator() constructor creates a new MediaStreamTrackGenerator object which consumes a stream of media frames and exposes a MediaStreamTrack. An object containing the property kind

Properties

Property	Type	Access	Description
Writable	WritableStream	get	The writable property of the MediaStreamTrackGenerator interface returns a WritableStream. This allows the writing of media frames to the MediaStreamTrackGenerator. The frames will be audio or video. The type is dictated by the kind of MediaStreamTrackGenerator that was created.

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<MediaStreamTrackGenerator>(...) or constructor new MediaStreamTrackGenerator(...)

const stream = await getUserMedia({ video: true });
const videoTrack = stream.getVideoTracks()[0];

const trackProcessor = new MediaStreamTrackProcessor({ track: videoTrack });
const trackGenerator = new MediaStreamTrackGenerator({ kind: "video" });

const transformer = new TransformStream({
  async transform(videoFrame, controller) {
    const barcodes = await detectBarcodes(videoFrame);
    const newFrame = highlightBarcodes(videoFrame, barcodes);
    videoFrame.close();
    controller.enqueue(newFrame);
  },
});

trackProcessor.readable
  .pipeThrough(transformer)
  .pipeTo(trackGenerator.writable);

See full example on MDN