[daveUK]

Theres no way to output a 24hz refresh over component. Component is 50/60hz only (depending on your region). TVs won't accept a non-standard component signal.

The only outputs that are going to support variable refresh rates are VGA, DVI and HDMI. And even then there's no guarantees - the only TVs *sure* to accept 24hz refresh are 120hz TVs (probably most 100hz as well), and even then, probably only over HDMI.

If you've got an analog TV, your only hope for relatively smooth playback is for the bug to be fixed.

Thats cleared it up then. Saved me hours messing with DTD and powerstrip

[Andydigital]

Deleted sorted the problem.

[rehnmark]

I have also notised the jitter with 24fps movies. It seems like XBMC dont do the 3:2 pulldown(1112233344) when playing at 60hz. It seems like it instead tries to play all frames at the same rate, and skips 4 frames every second resulting in very bad jitter (111222333444). Everything looks good when playing the same movie with VLC on the same computer/tv-screen/hz. It also works on XBMC for Xbox.
I really hope this can be fixed.

Another solution is to speedup the 24fps movie to 25fps, and play it at 50hz(This is also a feature that is implemented and works in XBMC for Xbox)

Otherwise this player rocks!

[midgetspy]

Saw that myself, but unfortunately it doesn't work with component tv-out as it cannot read the EDID data (only VGA, DVI and HDMI) and this is the only way to connect to my TV. Thanks anyway

Actually they "fixed" the Intel drivers so you can't even force 24Hz anymore apparently. My projector does 1080/24p but I've been unable to get my Intel G35 chipset to output 24Hz after quite a bit of effort. I asked on AVS and my findings were confirmed that there's really no way of doing 24Hz with Intel at the moment (even via HDMI/DVI/VGA). :-(

[m0gwai]

So any news about this problem, I spent my evening playing with XBMC and my Graphic card settings without any success.

One scene to use to see the problem is any opening scene from Harry Potter, where the camera zoom inside the Warner Bros logo, there I can clearly see jitter, if the developers want to have a look it's a good starting point, or get a benchmark DVD to test video processing - hell I'll pay for it if it help fixing the problem

I still have to run some more extensive tests but so far the """best""" result I get is using 60Hz, I tried using 24hz but doing so gives me a really bad frame rate.

I believe the key here is the inability of XBMC to render a steady 24fps, I mean I said it earlier when I'm playing 24fps content it can vary from 23.5 to 24.5 easily, all of this without a single drop frames and more than enough CPU resources. My video is 24fps, my display is running at 24hz but XBMC is rendering inconsistent fps, it's as simple as that, XBMC should render a steady 24fps and until it does there will be jitter during pan out/in.

I really hope this will be fixed soon, and if I can help I will - just let me know what to do.

[WiSo]

Open a trac ticket when it's not done yet. Would be nice if you could attach a small sample of the opening scene for testing.

[m0gwai]

I'm pretty sure I can cut a sample of the opening scene if that helps, but 1-2min of 1080p video might be big.

[idlerobbo]

I Thought this was something to do with the way I was ripping my BD's but I just downloaded Series 1 of Heroes in 720p and it is exactly the same... The opening 10 seconds is a good example. It has white text scroling upwards on a back background.

Just for the record I have anew HTPC connected via HDMI ual Core Athlon and 4GB ram. All files are played locally and CPU usage never seems to go over 35%. My frame rate, like others though fluctuates betwen 23.5 and 24.5, it is never a constant 24fps. I get no dropped frames either.

I do hope this can get sorted soon, I am holding off playing my BLurays until it is..

is there a trac ticket for this already?

[m0gwai]

I'm currently doing some test playing the same video with VLC and XBMC and it's clear the problem is due to XBMC, I will try to get some test results and cut samples for the developers.

[Freddo]

Did a trac ticket get opened for this? I can't seem to find it.

[swoop]

I did some testing and reading other threads and I came to a conclusion that the difference is only in XBMC implementation per platform.

Windows:
Playback is jittery, regardless of the refreshrate and framerate.

Live (ubuntu):
Playback is rendering-wise fine, no framerate / refreshrate sync.

Xbox:
Playback is rendering-wise fine, framerate / refreshrate sync can be configured.

Now, I'd like to stress that there are two problems (some people mix them up or think of them as one).

Problem no 1: Movie rendering must be done at a stable framerate. Windows XBMC is not capable of doing this.

Problem no 2: If stable framerate is established, playback should be synchronised with the monitor refreshrate i.e. playback should be faster (or slower). In this case a 24fps (23.976) movie should be played at 25fps (EU). This will give the sound a bit higher pitch but will result in perfectly smooth playback. Linux XBMC is not capable of doing this.

Since, as I read, XBOX version can do the framerate / refreshrate sync maybe there is a possibility to bring this capability to other platforms as well. Can anyone from XBMC comment on this?

cheers

[tknice1]

Wow, ok now I see what you guys are talking about with the slow pans. I guess its not as noticeable watching regular movies. I watched many of my Planet Earth documentaries and the pans really are very distracting. The mountain scene that you guys mentioned is very bad and should be reproducible by lots of people. In my case, my theater uses a sanyo plv-z2000 and the refresh rates I have available are 24/50/60. The jerkiness in the pan shots seems to be almost the same at 50 or 60khz.

I don't really have an alternative way of viewing the Planet Earth vobs on the HTPC (media center classic doesn't seem to work), but I'm going down now to play them through the PS3.

Hopefully the devs can reproduce this for themselves.

-Tom

[ashlar]

Just spent the better part of the weekend installing Ubuntu on my HTPC (double boot option with XP).
I managed to use the same 48Hz and 60Hz timings I used on XP, I created the modelines, it was not too hard.

The results are surprising:

1) Video tears and judders at both refresh rates, 48Hz is worse (it should be better, while playing back 23.976 material).
2) Performance seems worse under Linux, this surprised me the most. Same CPU, same 3.0GHz Core2 Duo. Nvidia 8800GT with lates drivers on both OSes. The birds killa sample plays perfectly under Windows, while it loses a ton of frames under Ubuntu Hardy.

In any case, judder is really bad under both OSes, even with 720p material that I'm 110% sure does not pose a problem for the decoding portion.

[tslayer]

Ashlar,

That is very surprising as I have none of what you described in linux.

What does your xorg.conf look like?

I have an 8600GT and here is my relevant xorg.conf:

Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
Option "TripleBuffer" "True"
Option "NoLogo" "True"
Option "PixmapCacheSize" "1000000"
Option "AllowSHMPixmaps" "0"
EndSection


And then on startup of xorg, I have this (in .xinitrc):

nvidia-settings -a InitialPixmapPlacement=2 -a GlyphCache=1 &

I am at 60Hz.

So, your results are very surprising.

I use no modelines.

[RickDeckard]

So any news about this problem, I spent my evening playing with XBMC and my Graphic card settings without any success.

One scene to use to see the problem is any opening scene from Harry Potter, where the camera zoom inside the Warner Bros logo, there I can clearly see jitter, if the developers want to have a look it's a good starting point, or get a benchmark DVD to test video processing - hell I'll pay for it if it help fixing the problem

I still have to run some more extensive tests but so far the """best""" result I get is using 60Hz, I tried using 24hz but doing so gives me a really bad frame rate.

I believe the key here is the inability of XBMC to render a steady 24fps, I mean I said it earlier when I'm playing 24fps content it can vary from 23.5 to 24.5 easily, all of this without a single drop frames and more than enough CPU resources. My video is 24fps, my display is running at 24hz but XBMC is rendering inconsistent fps, it's as simple as that, XBMC should render a steady 24fps and until it does there will be jitter during pan out/in.

I really hope this will be fixed soon, and if I can help I will - just let me know what to do.

Actually, I do not see any judder when playing 24 fps material with the videocard (nvidia 9600GT) output set at 1080p/24, even though I also have XBMC reporting a fluctuating framerate. Perhaps the display that is used is also a factor in all of this? I have tried both a Pioneer PDP-506XDE and a Panasonic PT-AE2000.