Function ConvertToRGBFrame

src/video_frame.ts:541–674

(
	frame: VideoFramePolyfill,
	format: VideoPixelFormat,
	colorSpace?: PredefinedColorSpace,
)

};

const ConvertToRGBFrame = async (
	frame: VideoFramePolyfill,
	format: VideoPixelFormat,
	colorSpace?: PredefinedColorSpace,
): Promise<VideoFramePolyfill> => {
	// 1. Let convertedFrame be a new VideoFrame...
	// (We construct it at the end, but we prepare the resource here)

	const width = frame.visibleRect!.width;
	const height = frame.visibleRect!.height;

	const scaler = new SoftwareScaleContext();
	const srcFmt = fromPixelFormat(frame.format!);
	const dstFmt = fromPixelFormat(format);

	// Configure scaling: Source -> Destination (Visible Size)
	scaler.getContext(
		width, height, srcFmt,
		width, height, dstFmt,
		SWS_BILINEAR,
	);

	// Allocate destination frame
	const dstFrame = new Frame();
	dstFrame.width = width;
	dstFrame.height = height;
	dstFrame.format = dstFmt;
	dstFrame.alloc();
	dstFrame.allocBuffer();

	// Apply destination color space settings to dstFrame
	// If colorSpace is not provided, srgb is used
	const targetColorSpace = colorSpace || 'srgb';
	if (targetColorSpace === 'srgb') {
		dstFrame.colorPrimaries = AVCOL_PRI_BT709;
		dstFrame.colorTrc = AVCOL_TRC_IEC61966_2_1;
		dstFrame.colorSpace = AVCOL_SPC_RGB;
		dstFrame.colorRange = AVCOL_RANGE_JPEG;
	} else if (targetColorSpace === 'display-p3') {
		dstFrame.colorPrimaries = AVCOL_PRI_SMPTE432;
		dstFrame.colorTrc = AVCOL_TRC_IEC61966_2_1;
		dstFrame.colorSpace = AVCOL_SPC_RGB;
		dstFrame.colorRange = AVCOL_RANGE_JPEG;
	}

	let srcFrame: Frame;
	let tempSrcFrame: Frame | null = null;

	// Determine if we need a temp frame due to flat buffer source or cropping
	const isFlatBuffer = !(frame.data instanceof Frame);
	const isCropped = frame.visibleRect!.x !== 0 || frame.visibleRect!.y !== 0
		|| frame.visibleRect!.width !== frame.codedWidth || frame.visibleRect!.height !== frame.codedHeight;

	if (isFlatBuffer || isCropped) {
		// Allocate temp frame for the visible region
		tempSrcFrame = new Frame();
		tempSrcFrame.width = width;
		tempSrcFrame.height = height;