[mythtv-users] MX440/Radeon wars (Was: Hardware ideas)

Clyde Stubbs clyde at htsoft.com
Fri Jun 25 09:20:37 EDT 2004

On Fri, Jun 25, 2004 at 01:22:41AM -0700, Jarod Wilson wrote:
> You select a progressive-scan resolution, like 640x480, 800x600 or 
> 1024x768, then the TV encoder scales and interlaces the signal to match 
> the specs you give in XF86Config (such as NTSC & SVideo). You don't 
> specify an interlaced mode to X.

HAve you actually tried this? And how could the tv-encoder (which
is a relatively minor bit of logic and analog circuitry) convert
progressive scan into interlaced? Surely in order to do that it would
have to buffer half frames.

Also, if you don't specify an interlaced mode to X (by which I
presume you mean that XF86Config contains a progressive scan
modeline or equivalent) then how do you tell the
TV encoder you want interlacing? Can you provide an example
of how you've done this? I'm more than happy to test your
claims if you can be a little more specific. Simply setting
up a 50Hz/31.5kHz 800x600 mode does not produce an interlaced
signal - I've tried it. It ouputs 31.5kHz progressive scan (and yes,
I scoped the signal to confirm this).

This is certainly not how the Radeon TV encoder works, BTW - you
definitely do specify an interlaced mode in XF86Config. 

> No, I believe they just use the TV-out encoder the way its intended...

Well, if you're right I'll take back every alternate half-frame of
what I've said about the MX440 :-) Please tell me how.


More information about the mythtv-users mailing list