[mythtv] Patch for Via XvMC VLD QMatrix Decoding

Ivor Hewitt ivor at ivor.org
Mon Sep 20 10:22:22 EDT 2004


Hi Isaac,

>>As I mentioned on unichrome enhancing the via osd is my project for this
>>week. :-)
>>Yes, it would be possible to patch up the BlendtoI44 to create a colour
>>list... but when I did this before the performance was, um, less than
>>impressive. Or to hack up a pseudo colour version of the palette...
>>(which produced okish results but didn't get rid of the OSD stutter).
>>    
>>
>
>How are you going to get a 16 color palette to look right, when all the OSD 
>themes assume a full color palette?  That's the entire reason it's in b&w.
>
>  
>
I was planning on producing a 16 color OSD theme to go with it.
I understand why it's blended down to b&w.... however the cpu overhead 
of creating the full yuv osd surface and then mixing it down to I44 is a 
killer on the EPIA.... and I thought I'd try a different approach.

>>However, I was planning on creating a new OSDI44Surface type, to hold
>>and handle the OSD in native format instead. I'll let you know if I get
>>anywhere.
>>    
>>
>
>That'll be even worse performance - the current blending code is MMX 
>optimized, and if you change the internal surface format, you'll lose that.
>  
>
But there would be no blending required to display the final osd, it 
would be held in I44 format throughout.
Of course, it might be a complete non-starter and I've probably 
overlooked something fundamental... I just thought I'd give it a bash.

I tried a couple of colorized via OSD's before... the first generated a 
pallete by picking most frequently used colours, the second just has a 
non-greyscale palette, with hardcoded detection to pick out certain 
colours in the blend code.
The first simply slowed things down even more... The second produced a 
reasonable OSD but the performance was no better and to be honest I 
found I preferred the grey scale!

Regards,
Ivor.




More information about the mythtv-dev mailing list