VideoFrame.VideoFrame()

The VideoFrame() constructor creates a new VideoFrame object representing a frame of a video.

Syntax

new VideoFrame(image, init);
new VideoFrame(data, init);

Parameters

The first type of constructor (see above) creates a new VideoFrame from a CanvasImageSource. Its parameters are:

image

A CanvasImageSource containing the image data for the new VideoFrame.

initOptional

A dictionary object containing the following:

duration

An integer representing the duration of the frame in microseconds.

timestamp

An integer representing the timestamp of the frame in microseconds.

alpha

A string, describing how the user agent should behave when dealing with alpha channels. The default value is "keep".

• "keep": Indicates that the user agent should preserve alpha channel data.
• "discard": Indicates that the user agent should ignore or remove alpha channel data.

The second type of constructor (see above) creates a new VideoFrame from an ArrayBuffer. Its parameters are:

data

An ArrayBuffer containing the data for the new VideoFrame.

init

A dictionary object containing the following:

format

A string representing the video pixel format. One of the following strings, which are fully described on the page for the format property:

• "I420"
• "I420A"
• "I422"
• "I444"
• "NV12"
• "RGBA"
• "RGBX"
• "BGRA"
• "BGRX"

codedWidth

An integer representing the timestamp of the frame in microseconds.

codedHeight

An integer representing the timestamp of the frame in microseconds.

timestamp

An integer representing the timestamp of the frame in microseconds.

durationOptional

An integer representing the duration of the frame in microseconds.

Examples

The following examples are from the article Video processing with WebCodecs. In this first example, a VideoFrame is created from a canvas.

const cnv = document.createElement('canvas');
// draw something on the canvas
…
let frame_from_canvas = new VideoFrame(cnv, { timestamp: 0 });

In the following example a VideoFrame is created from a BufferSource.

const pixelSize = 4;
const init = {timestamp: 0, codedWidth: 320, codedHeight: 200, format: 'RGBA'};
let data = new Uint8Array(init.codedWidth * init.codedHeight * pixelSize);
for (let x = 0; x < init.codedWidth; x++) {
  for (let y = 0; y < init.codedHeight; y++) {
    let offset = (y * init.codedWidth + x) * pixelSize;
    data[offset] = 0x7F;      // Red
    data[offset + 1] = 0xFF;  // Green
    data[offset + 2] = 0xD4;  // Blue
    data[offset + 3] = 0x0FF; // Alpha
  }
}
let frame = new VideoFrame(data, init);

Specifications

Browser compatibility