[mythtv-users] VDPAU update from the front lines, December 2008

Brad DerManouelian myth at dermanouelian.com
Tue Dec 2 15:25:04 UTC 2008

On Dec 2, 2008, at 12:04 AM, Yeechang Lee wrote:

> Brad DerManouelian <myth at dermanouelian.com> says:
>> I am currently running VDPAU code on my production system and I'm
>> quite happy with it, so calling it "very preliminary -- basically
>> conceptual" is not accurate. As soon at the OSD is working
>> correctly, it meets all my requirements and I would consider it
>> done.
> Another message of yours earlier tonight had already given me the
> sense that you were indeed using VDPAU in production.
> I'm surely not the only person, comfortable with his existing setup,
> who is nonetheless curious about what life is like on the
> ultra-bleeding video-technology edge. So:
> * Just how, exactly, is the OSD broken? I've read something of how
>  it's all white.

Mine is all white. It draws the shapes, but all colors are white so  
you can't see anything but white shapes. I haven't figured out why  
it's doing this on mine and not on other people's.

> * I've also read of MPEG2 blockiness. How is that in practice? Or are
>  all your recordings from the HD-PVR nowadays and that's not an
>  issue?

I record 3 ways. OTA, HD-PVR from DirectTV and PVR-350 from DirecTV.  
I'm not using VDPAU with PVR-350 recordings but I'm using it for  
everything else (I don't even know if the PVR-350 gets used any more  
since it's the lowest priority of 6 tuners).

HD-PVR recordings all look beautiful. I have a scan line at the top of  
my screen which I believe is a result of not having a modeline and  
haven't gotten around to fixing it (it's not bad enough for me to care  
right now).

OTA recordings have little vertical imperfections that make it look a  
little blocky. It's hard to describe. Definitely noticeable, but also  
acceptable and not bad enough for me to stop using it for these  

> * What other positives (beyond the near-zero CPU usage) and negatives,
>  big and small?

I think they're all explained above. The only other weirdness is a  
flash of green on the screen for a split second when starting to watch  
a recording. I haven't had any problems with the beta nVidia drivers  
but I don't use the system for anything but mythtv so here may be  
issues I don't encounter.

> I realize you don't want to push a whole bunch of people to rush into
> running trunk for VDPAU then complaining to the list "O HAI GUYZ TRUNK
> BROK MY MYTHTV LOLOLOLOL," but with that caveat out of the way, let's
> hear it all.

HD-PVR recordings are all 720p on my system. I haven't tried any other  
format. I also immediately bumped up my bitrate to the max since my  
system could now handle it. The older recordings look worse than  
before, but the newer ones look identical to OTA to me.

I ran a test last night by recording Heroes on both OTA and DirecTV  
via HD-PVR. I can't tell the difference between them. OTA is 5.5GB and  
HD-PVR is 1.1GB.

It was easy for me to jump into it because I was already running  
latest code from SVN and follow the lists so I know what is broken and  
what not to use, etc.


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