MediaStreamTrackProcessor

The MediaStreamTrackProcessor interface of the Insertable Streams for MediaStreamTrack API consumes a MediaStreamTrack object's source and generates a stream of media frames.

Constructor

MediaStreamTrackProcessor()

Creates a new MediaStreamTrackProcessor object.

Instance properties

MediaStreamTrackProcessor.readable

Returns a ReadableStream.

Examples

The following example is from the article Insertable streams for MediaStreamTrack, and demonstrates a barcode scanner application, which transforms the stream accessed via MediaStreamTrackProcessor.readable by highlighting the barcode.

js
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);

Specifications

Specification
MediaStreamTrack Insertable Media Processing using Streams
# track-processor-interface

Browser compatibility

BCD tables only load in the browser