MediaStream.getVideoTracks() - Web APIs 编辑

The getVideoTracks() method of the MediaStream interface returns a sequence of MediaStreamTrack objects representing the video tracks in this stream.

Syntax

var mediaStreamTracks[] = mediaStream.getVideoTracks();

Parameters

None.

Return value

An array of MediaStreamTrack objects, one for each video track contained in the media stream. Video tracks are those tracks whose kind property is video. The array is empty if the stream contains no video tracks.

Note: The order of the tracks is not defined by the specification, and may not be the same from one call to getVideoTracks() to another.

Early versions of this API included a special VideoStreamTrack interface which was used as the type for each entry in the list of video streams; however, this has since been merged into the main MediaStreamTrack interface.

Example

The following example, extracted from Chrome's Image Capture / Photo Resolution Sample, uses getVideoTracks() to retrieve a track for passing to the ImageCapture() constructor. 

var imageCapture;

navigator.mediaDevices.getUserMedia({video: true})
.then(mediaStream => {
  document.querySelector('video').srcObject = mediaStream;

  const track = mediaStream.getVideoTracks()[0];
  imageCapture = new ImageCapture(track);

  return imageCapture.getPhotoCapabilities();
})

Specifications

Browser compatibility

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