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VideoFrame: allocationSize() method

files/en-us/web/api/videoframe/allocationsize/index.md

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{{APIRef("Web Codecs API")}}{{AvailableInWorkers("window_and_dedicated")}}

The allocationSize() method of the {{domxref("VideoFrame")}} interface returns the number of bytes required to hold the video as filtered by options passed into the method.

Syntax

js-nolint
allocationSize()
allocationSize(options)

Parameters

  • options {{optional_inline}}
    • : An object containing the following:
      • rect {{optional_inline}}
        • : The rectangle of pixels to copy from the VideoFrame. If unspecified the {{domxref("VideoFrame.visibleRect","visibleRect")}} will be used. This is in the format of a dictionary object containing:
          • x: The x-coordinate.
          • y: The y-coordinate.
          • width: The width of the frame.
          • height: The height of the frame.
      • layout {{optional_inline}}
        • : A list containing the following values for each plane in the VideoFrame. Planes may not overlap. If unspecified the planes will be tightly packed:
          • offset
            • : An integer representing the offset in bytes where the given plane begins.
          • stride
            • : An integer representing the number of bytes, including padding, used by each row of the plane.
      • format {{Optional_Inline}}
        • : A pixel format for the pixel data in the destination. Can be set to "RGBA", "RGBX", "BGRA", "BGRX". If unspecified, the {{domxref("VideoFrame.format","format")}} will be used.
      • colorSpace {{Optional_Inline}}
        • : Specifies the color space of the pixel data in the destination. Can be set to "srgb" for the sRGB color space or "display-p3" for the display-p3 color space. Only applicable for RGB pixel formats. If unspecified, "srgb will be used.

Return value

An integer containing the number of bytes needed to hold the frame as specified by options.

Examples

In the following example the allocationSize is returned for the rectangle at top left with dimensions of 800 by 600.

js
const videoRect = {
  x: 0,
  y: 0,
  width: 800,
  height: 600,
};
let size = VideoFrame.allocationSize({ rect: videoRect });

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}