[mythtv-users] DirectFB output and fb modelines

[Juha Pahkala]

Actually, I think I was mistaken here, it seems now that the resolution
wasn't changed after all, but there seems to be some problems with the
picture on the tv, using directfb output. I'll have to start a new thread
after examining it a bit further.

sorry for the mixup, juhis

papenfuss at juneau.me.vt.edu said:
> 	I'm not sure that I can help much, but I can fill in a couple of gaps.
> I've got a slightly similar situation, but for a different reason.  I was
> trying to get the console framebuffer (with an aty128fb on an ATI card) to
> work
> at a custom resolution.  I need a custom resolution because I'm driving
> the
> NTSC TV directly with the VGA port (through a modulator, not a scan
> converter).
> Bottom line is I need *exact* VGA timings for NTSC compatibility, *AND*
> interlaced support.  What I found was a mess of framebuffer timings and
> modelines scattered throughout /etc/fb.modes (for fbset userspace
> programs),
> and within <kernel-src>/drivers/video/aty128fb.c and modedb.c.  I hacked
> the
> aty128fb source to allow interlaced modeline (I think, anyway), but I
> couldn't
> set it to be at any resolution I wanted.  Although I brewed up a specific
> 15.7kHz/30Hz/Interlaced modeline in /etc/fb.modes, changing to it didn't
> take.
> It found something "close" and used that.  I suspect it's the kernel
> framebuffer driver trying to protect you from yourself and picking a
> "real"
> modeline.
>
> 	You can probably look through the <kernel-src>/drivers/video/matrox/*
> files and make something out of it.  It went beyond my threshold of care
> this
> past weekend so I haven't looked any further into it.
>
> -Cory
>
> On Wed, 18 Feb 2004, Juha Pahkala wrote:
>
>> Hello,
>>
>> I've finally recently started to setup a MythTV box and already now
>> wondering why it took me so long to start :) MythTV absolutely rocks!!
>> So
>> thanks to all of you guys who made this happened.
>>
>> Anyway, let's get to the point. I've set up myth box without xfree, ie.
>> using QT/Embedded and DirectFB. I've now got it running but I'm having a
>> problem with DFB and framebuffer modelines. This is the case: I've got a
>> Matrox G400, which is quite picky with the timings of the tv-out, but
>> I've
>> got a modeline in /etc/fb.modes that works reasonably well. And this is
>> the modeline that mythfrontend runs on, since the qt/e part uses
>> directly
>> the framebuffer. But, when I try to watch tv (using a DVB-C card),
>> directfb switches the resolution to '704x576' for some reason, and all I
>> can see on the tv is green bars.
>>
>> I've tried to look through the menus and mailinglists, but haven't found
>> an answer to this question: Where does directfb fetch the modeline from?
>> How can I control that? I know it doesn't use /etc/directfbrc, since
>> I've
>> got the proper '720x576' mode set up there. And I don't have an entry
>> matching the '704x576' that dfb chooses in my /etc/fb.modes. So I'm
>> pretty
>> clueless here.
>>
>> Could somebody explain this to me?
>>
>> TIA, juhis
>>
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>
> --
> *************************************************************************
> * The prime directive of Linux:  					*
> * 	- learn what you don't know, 					*
> * 	- teach what you do.						*
> * 						(Just my 20 USm$)	*
> *************************************************************************
>
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>