[mythtv-users] Mythfrontend idle cpu consumption help

Michael T. Dean mtdean at thirdcontact.com
Wed Nov 11 19:03:28 UTC 2009

On 11/11/2009 10:26 AM, Johnny wrote:
>> Just food for thought, but if you are only doing SD to an SD screen
>> (~640-720x480), why bother with scaling up to 800x600

All existing 4:3 themes have a native resolution of 800x600, so 800x600 
is /not/ scaled up.

>>  only to have the
>> resulting output shown at (~640-720x480)?  Why not just use 640x480
>> natively all the way through from source to destination and avoid the
>> unnecessary scaling up and down.

Whether it's scaled /from/ 800x600 down to 640x480 by Myth, or not 
scaled and rendered at the native 800x600 resolution by Myth, the TV 
encoder will sample the resultant image to create an analog signal to 
send via the TV out.

> Because too many of the GUI elements outside of myth are completely
> unusable at 640x480.

Yes, Myth is really designed to be used at 800x600 or higher resolution.

>  I know I don't go out there much, but it is worth
> it for when I do. Also the quality difference is not perceptible, it
> is SD after all.

And, likely, based on the way the TV encoders work (assuming you're 
using S-Video/Composite output), you'll actually get better quality at 
800x600 or 1024x768 than you would get at 640x480.  The TV encoders 
actually sample the image that's created versus just "sending" that 
image directly--even if you create the image at 640x480 or 720x480 or 
480x480 or ...

Most importantly, however, there have actually been users who said that 
when they use the theme's native resolution (800x600 for 4:3 themes), 
they do /not/ get the excessive CPU usage.


More information about the mythtv-users mailing list