Qt6 Porting guidance: construct QVideoFrame from QImage

[davecotter]

it took me a long time to figure this out so i thought i'd share, so this is searchable in the future:

if anyone knows how to do this without performing the extra copy, i'd love to know. (ie: move the bits directly from the QImage into video memory, without going through the staging area. eg: am i just missing a QVideoFrame API that i don't know about?

static
QVideoFrame		QVideoFrame_fromImage(const QImage& image)
{
	QVideoFrameFormat	frameFormat(
		image.size(),
		QVideoFrameFormat::pixelFormatFromImageFormat(image.format()));
	QVideoFrame		vidFrame(frameFormat); vidFrame.map(QVideoFrame::WriteOnly);
	qsizetype		image_rowbytesI(image.bytesPerLine());
	qsizetype		frame_rowbytesI(vidFrame.bytesPerLine());
	const uchar*		imageBitsP(image.bits());
	uchar*			frameBitsP(vidFrame.bits());
	int			maxRowY(image.size().height());

	CF_ASSERT(image_rowbytesI <= frame_rowbytesI);

	for (int rowY = 0; rowY < maxRowY; ++rowY) {
		std::copy(imageBitsP, imageBitsP + image_rowbytesI, frameBitsP);
		imageBitsP += image_rowbytesI;
		frameBitsP += frame_rowbytesI;
	}

	vidFrame.unmap();
	return vidFrame;
}

[davecotter]

the correct answer is posted above, but a question remains: is this the most efficient method?