Re: [PATCH] omap3isp: preview: Add support for non-GRBG Bayer patterns

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Ivan,

On Wednesday 27 June 2012 16:42:01 Ivan T. Ivanov wrote:
> On Tue, 2012-06-26 at 03:30 +0200, Laurent Pinchart wrote:
> > On Saturday 23 June 2012 11:22:37 Sakari Ailus wrote:
> > > On Mon, Jun 18, 2012 at 04:30:53PM +0200, Laurent Pinchart wrote:
> > > > Rearrange the CFA interpolation coefficients table based on the Bayer
> > > > pattern. Modifying the table during streaming isn't supported anymore,
> > > > but didn't make sense in the first place anyway.
> > > 
> > > Why not? I could imagine someone might want to change the table while
> > > streaming to change the white balance, for example. Gamma tables or the
> > > SRGB matrix can be used to do mostly the same but we should leave the
> > > decision which one to use to the user space.
> > 
> > Because making the CFA table runtime-configurable brings an additional
> > complexity without a use case I'm aware of. The preview engine has
> > separate
> > gamma tables, white balance matrices, and RGB-to-RGB and RGB-to-YUV
> > matrices that can be modified during streaming. If a user really needs to
> > modify the CFA tables during streaming I'll be happy to implement that
> > (and even happier to receive a patch :-)), but I'm a bit reluctant to add
> > complexity to an already complex code without a real use case.
> 
> Sorry for not following this thread very closely. One use case for
> changing CFA table is to adjust sharpness of the frames coming out
> of the ISP. And we are doing exactly this in N9.

Thank you for the valuable feedback. Now we have a use case :-) I'll make sure 
the CFA table can be updated during streaming then. Are you fine with always 
specifying the table in SGRBG order, and letting the driver rearrange the 4 
blocks based on the input bayer pattern ?

-- 
Regards,

Laurent Pinchart