[steamhza]

hello guys


I have been trying a lot over the past few months, even with kodi 16, until I gave up.
Now I would like to go the other way around, and let you guys ask for information you may require to pinpoint the cause of this issue.

The problem: all videos stutter a little, obviously because of the 23.976 fps in all videos I have.
I just can't get it smooth, every fast movement (e.g. fast camera movement on scenery, buildings, etc.) seems to stutter.
What I have tried is virtually everything. From settings in the OS, in kodi, the TV, the video receiver, it just does not help.

My setup is the following:

PC with:
- Kodi 17.0-RC2 Git:5c40b5c1b8 Media Center Kodi
- SteamOS 2.0, which is in detail: Linux steamos 4.1.0-0.steamos.41-amd64 #1 SMP Debian 4.1.13-0+steamos15 (2016-11-22) x86_64 GNU/Linux
- nVidia 950 GTX, with driver version 367.27
- HDMI output, connecting to:
Samsung HT-F5500 5.1 receiver, finally to TV Samsung UE42F5070
These 3 devices are connected using HDMI.

Enabling the sync-framerates in kodi (video-playback) leads to lots of screen flickering at playback start, probably due to changing refresh rates, but does not fix the problem.
I am not sure how these settings made in kodi are affecting the TV, as the signal goes to the receiver first.
Also, I have tried all settings I could think of in the receiver-menu, as well as in the TV-menu.
One issue there is for sure all the marketing blah-blah, which says to "improve the picture", not stating what it actually does.

Assuming that this problem can be fixed, feel free to ask me every detail you may need to know (log entries, verbose output switches, etc.), I will provide anything needed to get rid of this.


thanks in advance for any help.

[Mnementh]

I would first of all test without the AVR in the mix, just go straight to the TV, straight away eliminate that as a possible cause. Also ensure you've turned off all frame interpolation rubbish on the TV etc.

Then it should just be a case of adjusting settings until you resolve the issue.

Might be worth making sure your TV actually has a 24p mode, I've had a quick google but can't find a definitive answer. I've owned Samsung TV's in the past (never again <shudder> ) and had issues with 24p on a couple of them.

[steamhza]

hello Mnementh


thanks for the hint. Sadly my cables are too short to get straight to the TV :/
I will try to think of something and reply soon.

As you are mentioning 24p ...my TV shows 1920x1080-60p, I have never seen it switch to 24p (this is shown in the text-banner on source-switch).
Is it necessary or even mandatory in this case? As a matter of fact, I have never seen the TV going to something else than 60p.

[fritsch]

Long known since years. For Nvidia you need a fixed up xorg.conf see our wiki.

[Mnementh]

Hey fritsch, the only thing relating to an Nvidia xorg.conf I can find on the wiki is about the screen tearing issue. Correct me if I'm wrong (and I more than likely am ) but that won't fix this issue as this is relating to the TV not switching to 24p so therefore you'll get the usual judder cause of mismatched refresh rates? Can you give a hint as to where there might be anything else relating to this as I honestly can't find it and it would be useful to know? Thanks

@steamhza if your TV isn't switching to 24p then you will always see this judder, you need to first of all find out if your TV supports 24p and if it does try and find out what is causing it to not switch. My money is on the AVR not sending through the EDID properly so the card doesn't know it can use 24p so it doesn't attempt to switch but that's just a WAG

[steamhza]

hm well, I did add a xorg.conf, it looks like this: http://pastebin.ca/3776608 according to the logs it is being parsed as well.

some of the commented stuff causes problem with steam big picture, meaning that X is starting, but I can't see anything but the steam-cursor and no menus, sound can be heard. However, I think the commented lines do not affect the issue here.
I also tried switching HDMI input jacks on the TV to HDMI-1 (it was HDMI-3 before), did not help as well.

The TV is still displaying 1920x1080-60p, with or without the adjust-TV-refresh-rate setting, which still causes lots of flickering and yet does not seem to affect anything, in every setting it stays with 60 fps at the TV.

Also I turned off everything I found in the picture-settings, both on TV and the receiver. The only option left is to connect it directly to the TV. But I am afraid of losing sound quality there, since I can plug in the TV directly, but would require optical cable to the receiver (which is handling the speakers). 5.1 would surely still work, but I don't know about DTS or whatever, since the HDMI connection supports more advanced audio features than optical cable AFAIK. I read about lots of restrictions with optical audio somewhere which do not apply to HDMI.

asking again: is 1920x1080-24 mandatory to fix my issue? It can not stay with 60fps, true?

[Mnementh]

True 24p (or 23.976Hz) playback is essential to resolve the judder issue

[wsnipex]

SteamOS Big Picture inhibits refresh rate changes, so kodi cannot switch your TV to 23,976 or even 24HZ.

[steamhza]

to my understanding games can switch resolutions, I guess the refresh rates as well...

[wsnipex]

to my understanding games can switch resolutions, I guess the refresh rates as well...

Last time I tried, it wasn't possible. This fact was also confirmed to me by Valve devs.
Granted, that was on steamos 1, but given the issues you see, it doesn't seem to have changed.

Anyway, providing a Debug Log might clear things up

[steamhza]

sure, here you go: http://pastebin.ca/3777115

[wsnipex]

22:42:05.088 T:139982545995840 INFO: XRANDR: /usr/lib/kodi/kodi-xrandr --screen 0 --output HDMI-0 --mode 0x1c8
22:42:05.182 T:139982545995840 INFO: GL: Maximum texture width: 16384
22:42:05.182 T:139982058530560 DEBUG: ActiveAE::SyncStream - average error of 83.962925, start adjusting
22:42:05.182 T:139982058530560 DEBUG: ActiveAE::SyncStream - average error 0.962925 below threshold of 30.000000
22:42:05.182 T:139982545995840 NOTICE: GL: Using VDPAU render method
22:42:05.182 T:139982545995840 NOTICE: GL: NPOT texture support detected
22:42:05.182 T:139982545995840 NOTICE: GL: Using GL_ARB_pixel_buffer_object
22:42:05.182 T:139982545995840 NOTICE: Using GL_TEXTURE_2D
22:42:06.543 T:139980299040512 DEBUG: CWebServer[8080]: request received for /jsonrpc?Base
22:42:06.573 T:139980299040512 DEBUG: Previous line repeats 3 times.
22:42:06.573 T:139980299040512 DEBUG: GetMovieId (/Media/somefilm.mkv), query = select idMovie from movie where idFile=42
22:42:08.045 T:139980609406720 NOTICE: CVideoPlayerAudio:rocess - stream stalled
22:42:08.114 T:139982545995840 ERROR: CWinEventsX11::MessagePump - missed XRR Events
22:42:08.114 T:139982545995840 DEBUG: NotifyXRREvent - notify display reset event
22:42:08.213 T:139982545995840 DEBUG: RecreateWindow - current output: HDMI-0, mode: 0x1c3, refresh: 60.000
22:42:08.213 T:139982545995840 DEBUG: OnLostDevice - notify display change event
22:42:08.213 T:139982545995840 DEBUG: Flush - flushing renderer

Looks like I assumed. It tries to switch to 23.970909 (because you lack a proper 23.976 mode) , but fails. Then it switches back to 60Hz.
Try starting kodi standalone, without Steam BPM or gnome and it should work.

btw: your kodi version is old, 17.0rc2 while 17.1rc1 is current.

[steamhza]

Kodi has the setting to adjust videos to the TV refresh rate. One may expect that it is possible to squeeze the 23.976fps in 60, but I see no effect on this. Is this option just bogus or applicable to something else?

sadly standalone is not a real option here, that brings other issues with the entire steam environment (controllers functionality, or too many modifications to steamOS that are reverted on every update).

[DJ_Izumi]

I'm not even sure this TV is capable of 24p. A lot of TVs while capable of ingesting 24p are still using displays locked to 60 or 50hz, so the display performs it's own pulldown to fit it's refresh rate. So even while it tells you '24p' it really means 'lulz, actually 60/50hz only!'. So it may be impossible to get smooth 24p on the display without resulting to it's own 'smooth' interpolation which has it's own downsides.

[wsnipex]

Kodi has the setting to adjust videos to the TV refresh rate. One may expect that it is possible to squeeze the 23.976fps in 60, but I see no effect on this. Is this option just bogus or applicable to something else?

sadly standalone is not a real option here, that brings other issues with the entire steam environment (controllers functionality, or too many modifications to steamOS that are reverted on every update).

just turn off refresh rate switching and it should work, although with the occasional micro stutter.