On 02/12/2022 17:56, Geert Uytterhoeven wrote:
Hi Tomi,
On Fri, Dec 2, 2022 at 4:32 PM Tomi Valkeinen
<tomi.valkeinen@xxxxxxxxxxxxxxxx> wrote:
On 02/12/2022 15:16, Tomi Valkeinen wrote:
These kms++ patches add support for Y210 format.
I didn't find a super clear description of the byte order for Y210
anywhere. If someone knows what it is supposed to be, I'd appreciate
verifying the code =).
Actually, this:
https://learn.microsoft.com/en-us/windows/win32/medfound/10-bit-and-16-bit-yuv-video-formats#overview
indicates that the 10-bit values should be shifted by 6. So the drawing
code in this series is probably not right.
https://elixir.bootlin.com/linux/latest/source/include/uapi/drm/drm_fourcc.h#L212
seems to confirm that?
Hmm, indeed. I've looked at that before but I couldn't decipher it, but
now the text makes sense. Although afaics, it doesn't say that each
component is a 16-bit little endian. And I don't get the "little endian
per 2 Y pixels".
So if I get this right...
The first byte in memory is the two lowest bits of Y0 in bits 6 and 7.
The rest of the first byte is zero padding.
The second byte is the 8 highest bits of Y0.
Then following the same method, Cb, Y1, Cr.
Tomi
