Function InitializeFrameWithResource

src/video_frame.ts:944–1011

(
	init: VideoFrameInit,
	frame: VideoFramePolyfill,
	resource: Frame,
	codedWidth: number,
	codedHeight: number,
	baseRotation: number,
	baseFlip: boolean,
	defaultDisplayWidth: number,
	defaultDisplayHeight: number,
	timestamp: number,
)

};

const InitializeFrameWithResource = (
	init: VideoFrameInit,
	frame: VideoFramePolyfill,
	resource: Frame,
	codedWidth: number,
	codedHeight: number,
	baseRotation: number,
	baseFlip: boolean,
	defaultDisplayWidth: number,
	defaultDisplayHeight: number,
	timestamp: number,
) => {
	// 1. Let format be null.
	let format: VideoPixelFormat | null = null;
	// 2. If resource uses a recognized VideoPixelFormat, assign that format.
	format = toPixelFormat(resource.format as AVPixelFormat) as VideoPixelFormat;

	// 3. Let validInit be the result of running the Validate VideoFrameInit algorithm.
	if (!ValidateVideoFrameInit(init, format, codedWidth, codedHeight)) {
		throw new TypeError('Invalid VideoFrameInit');
	}

	// 4. Assign a new reference for resource to frame’s [[resource reference]].
	frame.data = resource;

	// 5. If init.alpha is discard, assign format’s equivalent opaque format to format.
	if (init.alpha === 'discard' && format) {
		format = getEquivalentOpaqueFormat(format) as VideoPixelFormat;
	}

	// 6. Assign format to [[format]].
	// @ts-expect-error Write to readonly
	frame.format = format;
	// 7. Assign codedWidth and codedHeight...
	// @ts-expect-error Write to readonly
	frame.codedWidth = codedWidth;
	// @ts-expect-error Write to readonly
	frame.codedHeight = codedHeight;

	// 8. Let defaultVisibleRect be a new DOMRect...
	const defaultVisibleRect = new DOMRectReadOnlyPolyfill(0, 0, codedWidth, codedHeight);

	// 9. Run the Initialize Visible Rect, Orientation, and Display Size algorithm.
	InitializeVisibleRectOrientationAndDisplaySize(
		init, frame, defaultVisibleRect, baseRotation, baseFlip, defaultDisplayWidth, defaultDisplayHeight,
	);

	// 10. Assign init.duration to frame's [[duration]].
	// @ts-expect-error Write to readonly
	frame.duration = init.duration != null ? Math.trunc(init.duration) : null;

	// 11. Assign init.timestamp to frame's [[timestamp]].
	// @ts-expect-error Write to readonly
	frame.timestamp = Math.trunc(timestamp);

	// 12. If resource has a known VideoColorSpace, assign its value...
	// @ts-expect-error Write to readonly
	frame.colorSpace = new VideoColorSpacePolyfill({