Re: [Linux-fbdev-devel] YUV Framebuffer

[Rhee, C. J. <jr...@qu...>]

Hi,

Interleaved means YCBCR is on the same plane in this order.
Y CB Y CR Y CB Y CR.... (TV-Out)

The problem of matching Y=3DG, CB=3DB and CR=3DR for RGB offset is that =
the
pixel cannot be represented directly since CB/CR gets shared between Ys.

So, bitsperpixel would be 16 bit and both B and R offset will be 8.

Joon

-----Original Message-----
From: ge...@li... [mailto:ge...@li...]=20
Sent: Tuesday, October 16, 2007 11:58 PM
To: Rhee, C. Joon
Cc: Linux Frame Buffer Device Development
Subject: Re: [Linux-fbdev-devel] YUV Framebuffer

On Tue, 16 Oct 2007, Rhee, C. Joon wrote:
> Is it possible to create framebuffer color format in YUV (eg. YUV422
> interleaved) and expose it through /dev/fb?
>=20
> What would be fb_info type? =20

What do you mean with `interleaved'?
Even and odd frames are separate (interlace)?

For YUV422, you have to add a new visual type.

A long time ago, I used this for a non-public test project:

#define FB_TYPE_PACKED_PIXELS_LACED     5       /* Interlaced Packed
Pixels */
#define FB_TYPE_PACKED_PIXELS_4AREAS    6       /* 4 areas of Packed
Pixels */

#define FB_VISUAL_YCBCR422              6       /* YCbCr 4:2:2 */
#define FB_VISUAL_YCBCR420              7       /* YCbCr 4:2:0 */

> And how about about fb_var_screeninfo.green/blue/red offset?=20

Just assume red, green, and blue mean Y, U, and V?

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
ge...@li...

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But
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like that.
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