[mythtv] [ivtv-users] PVR-350 and MythTV support

Ricardo Lugo punka at cfl.rr.com
Wed Feb 7 20:43:42 UTC 2007

On Feb 7, 2007, at 12:46 PM, Erik Mouw wrote:

> On Wed, Feb 07, 2007 at 10:07:28AM -0500, Ricardo Lugo wrote:
>> On Feb 6, 2007, at 10:04 AM, Jeff Simpson wrote:
>>> #3, Framebuffer is slow slow slow slow, and it EATS cpu. I have a  
>>> 3ghz
>>> machine, but the menus are still slow. I often find the X session
>>> using 50 or 60% of my cpu, just SITTING there. Forget trying to  
>>> run it
>>> at the same time as another X session, it jumps to a full 100%.
>>> Playing anything that isn't a native mpeg2 video makes the system
>>> crawl.
>> Yup, writing directly to the framebuffer is slow. And yes, it is the
>> main source of problems with the OSD in Myth.
> What OSD problems? Curious, cause I haven't had any so far.

Try "Edit Recording" while watching a recording: I've never gotten it  
to work. Or using the PVR-350's TV-out with MythTV on a big-endian  

>> That's why the 350 framebuffer support should be taken out of Myth,
>> not the entire support for the PVR-350.
> If that means that you can't use a PVR-350 to display both menu and
> video, I don't agree. It's one of the major advantages of the 350: one
> card does all.

I'm not advocating removal of the OSD at all. I couldn't live without  

I'm suggesting that the OSD be accomplished through regular calls to  
X through the Xdriver and XV - ie like any other video card out  
there, but that the MPEG2 decoding still be done by the 350.

Currently, the OSD is drawn by MythTV writing directly to the 350's  
framebuffer. This is time-consuming to maintain, and buggy: On my PPC  
machine (big-endian) the OSD colors are off, and the time calculation  
for the duration of the recording is also off. Commercial skipping  
sometimes results in MythTV losing control of the OSD. Editing a  
Recording causes MythTV to lose control of the OSD - I have to  
restart X to get control again.

We have a stable Xdriver that draws graphics for us, and does so very  
efficiently through the use of XV. Why should Myth write directly to  
the card, when it can just write to X and let the Xdriver handle it?  
This is something that can be maintained for the PVR-350.

- Rick

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