MediaStreamTrackGenerator

{{APIRef("Insertable Streams for MediaStreamTrack API")}}{{SeeCompatTable}}{{Non-standard_Header}}

[!NOTE] Consider using {{domxref("VideoTrackGenerator")}} instead.

The MediaStreamTrackGenerator interface of the Insertable Streams for MediaStreamTrack API creates a {{domxref("WritableStream")}} that acts as a {{domxref("MediaStreamTrack")}} source. The object consumes a stream of media frames as input, which can be audio or video frames.

Constructor

• {{domxref("MediaStreamTrackGenerator.MediaStreamTrackGenerator", "MediaStreamTrackGenerator()")}} {{Experimental_Inline}} {{Non-standard_Inline}}
  • : Creates a new MediaStreamTrackGenerator object which accepts either {{domxref("VideoFrame")}} or {{domxref("AudioData")}} objects.

Instance properties

This interface also inherits properties from {{domxref("MediaStreamTrack")}}.

• {{domxref("MediaStreamTrackGenerator.writable")}} {{Experimental_Inline}} {{Non-standard_Inline}}
  • : A {{domxref("WritableStream")}}.

Instance methods

This interface doesn't implement any specific methods, but inherits methods from {{domxref("MediaStreamTrack")}}.

Examples

The following example is from the article Insertable streams for MediaStreamTrack, and demonstrates a barcode scanner application, which process barcodes and highlights them before writing the transformed frames to the writable stream of {{domxref("MediaStreamTrackGenerator.writable")}}.

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 also

• {{domxref("VideoTrackGenerator")}}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}