[mythtvnz] VDPAU package can be removed?

Mon May 11 11:30:59 BST 2009

Wow, awesome post, thanks :)

Thanks also to all the others who posted on the subject, it all now
makes sense.

So now, like Aaron the real challenge is convincing the misses I need a
new TV ;)

Dylan

On Mon, 2009-05-11 at 11:52 +1200, Aaron Drysdale wrote:
> >I get rather weird behaviour with my TV and component out. My TV is a
> Sony Bravia KLV-40V300A. 
> >
> >The TV seems to know the difference between a PC and a more typical
> component like a DVD player.
> >
> >When I connect using VGA or DVI/HDMI it switches into PC mode. In
> this mode everything looks the way you'd expect if you pluged >into a
> standard LCD monitor.  A good chunk of the TV menu options are
> disabled (Colour, Hue, Sharpness, etc...)
> >
> >When I connect using Component (or sometimes via DVI/HDMI if I've
> been messing with nvidia-settings) it seems to switch to a standard
> >mode, typically 720p, and in this mode the colours are dark and look
> terrible. Overscan is enabled clipping the edges from the picture.
> >
> >I can only guess that a DVD player has a different colour profile
> from a PC and the TV is trying to compensate. I suspect if I messed
> with >the colour setting within nvidia-settings I could make it look
> right, but that sounds a great deal like hard work.
> >
> >I did the above testing when I got the TV, so pre-VDPAU, probably
> around ~173.
> >
> >Does anyone know if there is a flag I can pass to the video driver to
> make it look right in this mode?
> >Does anyone else see similar issues with different brands/models of
> TV?
> >
> >None of the above really worries me as I don't use the component out,
> but I'm still curious.
> >
> >Dylan
> 
> 
> 
> I have done a LOT of reading and playing around with my system over
> the weekend, and I believe that I now understand fully what is going
> on, and also why you’re seeing the behavior you’ve described. Perhaps
> well known by others, but hopefully educational for a few. BTW, I’ve
> also got the KLV-40V300A TV. When I look back, I see a few people and
> given me the solutions early on, I just didn’t recognize them for what
> they were!
> 
>  
> 
> When I first created this thread, I was having 2 problems – judder,
> particularly evident when watching ticker tapes on news programs, and
> tearing during playback. I’ve now solved both of these, but have had
> to make a compromise along the way.
> 
>  
> 
> First, this TV supports 1360x768 native resolution, at 60 Hz. At this
> resolution, I get 1:1 pixel mapping, and absolutely perfect desktop
> and GUI with no overscan.
> 
>  
> 
> The judder is caused by a mismatch between the broadcast refresh rate
> (25 fps defined by PAL) and the screen refresh rate of 60 Hz. The
> resulting 3:2 pulldown creates telecine judder. 
> 
> http://en.wikipedia.org/wiki/Telecine#Telecine_judder
> 
>  
> 
> The solution to this is to run the screen at 50Hz – no 3:2 pulldown,
> and hence no judder. However, 1360x768 is a VESA format and VESA
> doesn’t support refresh rates below 60Hz. I confirmed this by looking
> at the EDID of this TV, and at least according to that 1360x768 50 Hz
> is not a supported refresh rate. To get 50Hz refresh rate, I need to
> run at 1280x720 (ie 720p). However (and here’s the compromise) if I do
> that the TV has the smarts to think I’m now connecting a broadcast
> device (STB, DVD Player, etc) and turns on overscan and “16-235”
> studio levels. 
> 
>  
> 
> Overscan is a common “feature” of most TVs.
> (http://en.wikipedia.org/wiki/Overscan) High end, and newer DFPs,
> often have a feature in their menus to turn overscan off. The Sony
> Bravia V Series does not.
> 
>  
> 
> Colours don’t look natural. Broadcast video uses colour levels in the
> range 16 – 235, while PCs use a colour range 0 – 255. So my graphics
> card is sending out video as 0 – 255, however the TV has now switched
> itself to “broadcast” mode and is interpreting the colours in the
> range 16-255. Which means, the colours at the top and bottom end of
> the range are all collapsed together. Darks and lights have lost a lot
> of definition and contrast. Again, high end TVs often have the ability
> to allow the user to switch colour modes – the Sony Bravia V Series
> does not. (Although I did find that going into the TV menu Picture >
> Advanced Settings > Colour Mode and changing to Wide did help a lot.)
> The only way (I think) to fix this properly is to get the video driver
> to scale the colour levels on output. This is something the Windows
> nVidia driver allows you to do, and I found this post which suggests
> the Linux driver developers will also support this in future.
> 
> http://www.nvnews.net/vbulletin/showthread.php?t=130240
> 
>  
> 
> Of course, at 720p I also lose the 1:1 pixel mapping, and the TV
> scales the resolution up to its native resolution. Which means that
> the desktop and GUI don’t look as good, although I think video
> playback looks better. Perhaps the TV’s hardware scaling is better
> than software scaling?
> 
> 
> 
> So all up, where am I now? I’m using HDMI 720p @ 50Hz, and get
> overscan in the desktop, but the Mythtv GUI and video playback look
> great after setting the appropriate scaling and X/Y Offsets in the
> Mythtv Frontend settings menu. Since this is a dedicated Media PC, I’m
> going to stick with this. Colours look slightly unnatural (although
> improved after playing with the TV brightness and colours) but most
> importantly the playback is very smooth. I’m waiting for nVidia to
> provide a solution to the colours problem. Also, XBMC which I also use
> supports switching refresh rates, so when playing back NTSC source
> videos it automatically switches to 60Hz and I get smooth video there
> too.
> 
>  
> 
> I also eventually fixed the tearing problem. Disabled composite
> according to JYA’s VDPAU FAQ. Interestingly it fixes the problem even
> when I don’t have VDPAU enabled.
> 
>  
> 
> Of course, now I know that ultimately the best solution would be a new
> TV, but you can imagine how that went down with the wife! Ideally, I
> need a TV that supports 1920x1080 full HD with 1:1 pixel mapping; at
> 24Hz, 50Hz and 60Hz refresh rates; the ability to switch on/off
> overscan; and switch between PC Levels and Broadcast Levels.
> 
>  
> 
> I hope all this helps someone.
> 
>  
> 
> Aaron
> 
> 
> 
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