[mythtv] testing mythtv-vid branch - questions & problems

Daniel Kristjansson danielk at cuymedia.net
Fri Jun 29 14:49:16 UTC 2007

On Fri, 2007-06-29 at 17:17 +1000, Matt Doran wrote:
> Firstly, what settings are the equivalent of the old trunk xv renderer, 
> and OSD renderer?  Is it xv-blit and softblend respectively?

Yes, this is the default in mythtv-vid as well.

> I've been using Standard, XV, Bob on trunk .... and when I use these
> settings on the vid branch the output is the same as it was on trunk.

Makes sense

> When I switch to the "opengl" renderer things are not so good.  I get a 
> huge amount of tearing .... the video looks awful with any panning.  It 
> seems to happen no matter what deinterlacer or OSD renderer I chose.   
> What combinations of decoder/renderer/OSD/deinterlacer are recommended 
> for the best results?

The opengl renderer is new so we don't really know what works
well for a large range of hardware. Your card, as noted below,
may simply not be able to handle any of the opengl rendering
methods Mark has implemented.

> Also when I enable any of the open GL deinterlacers, I get the following 
> in the logs ... does this indicate a problem?
>     2007-06-28 23:45:15.560 VDP: GetFilteredDeint() :  ->
>     'opengllinearblend'
>     2007-06-28 23:45:15.564 FilterManager: failed to load filter
>     'opengllinearblend', no such filter exists

This looks like a bug. Could you note this on the #2287
ticket? Just so it doesn't fall through the cracks..

> Others have good success with the OpenGL renderer, so I'm wondering what 
> I'm missing.    I'm using an onboard Nvidia 6150 video board... is this 
> card powerful enough?  What boards have others had success with?

I'm using a 6600 GT for testing and it can handle 640x480, you
need a better card for HDTV resolutions. An on board video card
that doesn't have it's own high speed memory will probably not
perform as well as a separate card in most circumstances. While
it can load the video frames themselves more quickly, it can
not filter or scale them as quickly. Also, make sure you have
dual channel memory access enabled for the best performance
(using matched RAM chips, the BIOS POST will tell you if you
have dual channel memory access.)

> I'm using version 9631 of the nvidia drivers, and a fairly standard 
> Ubuntu Feisty system (AMD X2 3600+, 1GB RAM).

7667 seems to be the most stable release. Aside from some
limited tearing issues, 8776 works for me. The 9xxx drivers no
longer cause segfaults, but I wouldn't recommend them either.

-- Daniel

BTW Make sure you restore your DB after testing, the mythtv-vid
    branch does change the DB & DB schema revision number.

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