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XBMC for Linux VDPAU - NVIDIA GPU video decoding support (now in the mainline SVN) - Printable Version

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- boba23 - 2009-05-05 22:55

Ok, problem fixed, I disabled dynamic twin view in xorg.conf, and now my 24p content is auto adjusted to 24hz :-)

boba


- olympia - 2009-05-05 23:00

boba23 Wrote:Ok, problem fixed, I disabled dynamic twin view in xorg.conf, and now my 24p content is auto adjusted to 24hz :-)

boba

Great!
Could you please also try if it crash on playback stopping if strictbinding disabled?


- olympia - 2009-05-05 23:02

boba23 Wrote:It's a Panasonic 46PZ80.

Anyway, I have exactly the same TV set Smile


- boba23 - 2009-05-05 23:29

olympia Wrote:Great!
Could you please also try if it crash on playback stopping if strictbinding disabled?

I have

<videoplayer>
<strictbinding>false</strictbinding>
<vdpau_allow_xrandr>true</vdpau_allow_xrandr>
</videoplayer>

in my advancedsettings.xml.

While checking 24fps playback before I had no crash on stopping. Though I stopped the movies manually, you were talking about crashing when the movie ends and stops then, right?

boba


- boba23 - 2009-05-05 23:35

Ya right olympia. Trying 1080p 24p vdpau playback I get a crash to desktop when stopping the movie. I only tested SD Material before.
Plus I gotta say, that 1080p 24p playback was really everything but smooth, no dropped frames but playing that movie at 50hz looked WAY better, 24hz was just bad.
How is 24p playback for you on the PZ80 olympia? Btw, my SD 24hz test with a Lost episode was smooth as silk. Is this a vdpau issue, too?

boba


- olympia - 2009-05-05 23:55

boba23 Wrote:Ya right olympia. Trying 1080p 24p vdpau playback I get a crash to desktop when stopping the movie. I only tested SD Material before.
Plus I gotta say, that 1080p 24p playback was really everything but smooth, no dropped frames but playing that movie at 50hz looked WAY better, 24hz was just bad.
How is 24p playback for you on the PZ80 olympia? Btw, my SD 24hz test with a Lost episode was smooth as silk. Is this a vdpau issue, too?

boba

24Hz playback is perfect for me on this TV with 1080p sources.
I am not sure on how you could test 24Hz with SD stuffConfused
They are usually not encoded with 23.976fps...


- boba23 - 2009-05-06 00:00

olympia Wrote:24Hz playback is perfect for me on this TV with 1080p sources.
I am not sure on how you could test 24Hz with SD stuffConfused
They are usually not encoded with 23.976fps...

Oh alright, then my bad, that Lost episode is a NTSC rip, so prolly 23.976 which meant for me 24hz ;-)
Anyway, I am just testing "Baader Meinhof Complex" 1080p/24p. Software playback is smooth as silk, using VDPAU I get stuttering, only when outputting 24p. VDPAU plus 50hz output again is smooth as silk. I read a few pages earlier in this thread that others have 24p vdpau stuttering problems as well. It seems also file/movie dependent ...

boba


- olympia - 2009-05-06 00:09

boba23 Wrote:Oh alright, then my bad, that Lost episode is a NTSC rip, so prolly 23.976 which meant for me 24hz ;-)

NTSC is 29.97 fps Tongue


- boba23 - 2009-05-06 00:12

well then what's the difference between 23.976 and exactly 24? 24 = 24p, and 23.976 is what? ;-)
Anyway, you have any idea what could cause my 24p vdpau stuttering? Since it works fine for you ... I guess it might be an xorg.conf/nvidia issue?

Edit: Wikipedia says ...

23.976p

Many 24p productions, especially those that are made only for TV and video distribution, actually have a frame rate of 24 * 29.97 / 30 frame/s, or 23.976frame/s (24/100.1% to be exact). Many use the term "24p" as a shorthand for this frame rate, since "23.976" does not roll off the tongue as easily. This is because the "30frame/s" framerate of NTSC is actually 30/100.1%, also referred to as 29.97frame/s – this framerate is matched when video at 23.976frame/s has a 3:2 pulldown applied. Similarly, 60i is shorthand for 60/100.1% fields per second.
-----
So I guess 23.976 is 24p by definition, isn't it ;-)

boba


- pyrates - 2009-05-06 03:51

boba23 Wrote:well then what's the difference between 23.976 and exactly 24? 24 = 24p, and 23.976 is what? ;-)
Anyway, you have any idea what could cause my 24p vdpau stuttering? Since it works fine for you ... I guess it might be an xorg.conf/nvidia issue?

Edit: Wikipedia says ...

23.976p

Many 24p productions, especially those that are made only for TV and video distribution, actually have a frame rate of 24 * 29.97 / 30 frame/s, or 23.976frame/s (24/100.1% to be exact). Many use the term "24p" as a shorthand for this frame rate, since "23.976" does not roll off the tongue as easily. This is because the "30frame/s" framerate of NTSC is actually 30/100.1%, also referred to as 29.97frame/s – this framerate is matched when video at 23.976frame/s has a 3:2 pulldown applied. Similarly, 60i is shorthand for 60/100.1% fields per second.
-----
So I guess 23.976 is 24p by definition, isn't it ;-)

boba

Actually, the original source is 24 fps. But a long time ago, film makers started dropping 1 frame of every 50 to make it 23.976 fps. The sound equipment for editing video and audio has been adjusted to work with that and they don't want to change that. That is why no one does 24 frames a second. The timing is 24000/1001. Adding in the percentage just makes it confusing.

The same thing applies with tv shows filmed at 30 fps. The timing is 30000/1001. Again adding in the percentage just makes it confusing. If you encode from dvd's and look at the timing information, they use both these standards. The result is that the sound stays in sync.

And the official calculation for hdtv cameras is 24*30000/1001/30.


- freddyflinty - 2009-05-06 06:47

freddyflinty Wrote:Can someone please explain the situation with scaling and VDPAU? I have searched this entire thread and not come up with any clear answer.

Q: With VDPAU enabled, what scaler is being used for VDPAU decoded video (e.g. h.264) and non-VDPAU decoded content (e.g. XviD or DVD MPEG2)?

The settings I used to use (Lancsoz) are not working unless I turn the renderer back to "auto".

Sorry to quote myself here, but isn't anyone else watching VDPAU and non-VDPAU (e.g. DVD) content and looking for the best possible picture quality on both?

I just want to confirm that there is a bug stopping high quality upscaling from working when VDPAU is set as the renderer...


- motd2k - 2009-05-06 08:04

Its not a bug.


- freddyflinty - 2009-05-06 08:44

motd2k Wrote:Its not a bug.

motd2k -- you are the man, thank you so much for all of your efforts with VDPAU, you have changed the game for Linux media centers.

Could you please ellaborate? I am just trying to understand what scaling is taking place for VDPAU and non-VDPAU content (when I hit "o" and it does/doesn't say VDPAU) when the VDPAU renderer is set.

So, like this:
1) VDPAU turned on, high quality upscaling set to "always" and "lancsoz"
2) VDPAU being used to decode 1280x720 h.264 video and output to 1360x768 TV (my understanding is VDPAU takes care and does nice job)
3) VDPAU not being used to decode 720x480 MPEG2 video and output to 1360x768 TV (my understanding is unclear here)

Thanks so much!


- motd2k - 2009-05-06 08:54

VDPAU is scaling internally, I dont think they ever published which algorithm they used, however they implied it might be bi-cubic.

So in your 3 scenarions...

1) VDPAU would scale internally
2) VDPAU would scale internally
3) XBMC would scale using whatever setting you set


- freddyflinty - 2009-05-06 08:58

motd2k Wrote:VDPAU is scaling internally, I dont think they ever published which algorithm they used, however they implied it might be bi-cubic.

Thanks motd2k -- really appreciate your time and effort on all this. Have already donated twice and plan to again once Babylon goes gold.

So, then at least in my setup (Babylon RC1 XBMC Live) scenario #3 isn't working as expected. The high quality upscaling option is definitely not being used (as indicated by lower-than-expected CPU usage, which goes back up when I change the renderer to "auto").

I would also add that if indeed Nvidia's scaler is bi-cubic, then it may make sense in the future to have an "VDPAU only for HD content" type of option similar to the one for HQ video upscaling as the final quality would probably be better for SD h.264/VC-1 video if the HQ upscalers are being used...