Re: [Libvisual-devel] Flag for RGB/BGR support

[salsaman <sal...@xs...>]

Burkhard Plaum wrote:

>
>> Then I may have to swap the channels in LiVES. Unfortunately this 
>> will probably halve the frame rate for libvisual.
>
>
> I think libvisual should handle this. Many X11 installations also
> have 32 bit BGR XImages by default. This colorspace thing will
> show up everywhere.


OK. I've tested GBR --> RGB conversion in LiVES, and it doesn't really 
slow things down too much.
But still, for some hosts it might be nice to have the option to let 
libvisual handle the conversion as well.



>
>> MMX is no good for me, LiVES is cross platform. However, the livido 
>> writers might be interested, since liblivido will be platform specific.
>
>
> gavl does runtime autodetection, and on non mmx platforms, it won't 
> try to
> compile the mmx stuff at all. The accelleration modi can be selected
> using individual flags (like in libvisual) or with
> simple speed<->quality sliders.


I've suggested to the other livido authors that we have a standard 
#define for processor type. This value could also be passed to libvisual 
via the wrapper (though obviously not at compile time).



>
>> Yes. I have horizontal subsampling for BGR->UYVY
>>
>> I need a vertical subsample for UYVY->YUV420. Oh well, I will ask 
>> Niels sometime.
>
>
> In principle, gavl can also support (slow) high quality conversions.
> Up to now, I could not find any visible errors due to the lack of
> interpolating, so I didn't write them yet.
>
I found without the horizontal subsampling there was a visible 
"striping" on the screen, but then there were probably other sources of 
error at the time.

Cheers,
Salsaman/Gabriel.