ImageDecoder.decode()

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The decode() method of the ImageDecoder interface enqueues a control message to decode the frame of an image.

Syntax

ImageDecoder.decode(options)

Parameters

optionsOptional

An object containing the following members:

frameIndexOptional

An integer representing the index of the frame to decode. Defaults to 0 (the first frame).

completeFramesOnlyOptional

A boolean defaulting to true. When false indicates that for progressive images the decoder may output an image with reduced detail.

Return Value

A promise that resolves with an object containing the following members:

image

A VideoFrame containing the decoded image.

complete

A boolean, if true indicates that image contains the final full-detail output.

Exceptions

If an error occurs, the promise will resolve with following exception:

InvalidStateError DOMException

Returned if any of the following conditions apply:

  • close is true, meaning close() has already been called.
  • The requested frame does not exist.

Examples

The following example decodes the second frame (at index 1) and prints the resulting VideoFrame to the console.

console.log(imageDecoder.decode({frameIndex: 1}));

Specifications

Specification
WebCodecs
# dom-imagedecoder-decode

Browser compatibility

BCD tables only load in the browser