Newest version of Plex Media Player broke something on 23.976fps playback

Plex Players Desktop Players
61

Thanks for the comment. Is there any way that I can try this, or does it have to be implemented by a developer?

62

Yes, sure you can try this. BUT you need to compile Plex Media Player on your own (with updated mpv) and that’s pretty complex. This has been already discussed _>

It’s complex and difficult but totally possible. I wanted that too but was not able to do so. Compiling mpv is very easy, but Qt cannot be compiled with mingw. 
extra work in Visual Studio.
Try it, if you can! :smiley:
But the better solution would be that the dev’s implement this. (as they already have all dependencies configured - I think ^^)

63

Wah, thanks for the great info, but I think, in all honesty, it is outside of my skill set.

Plex developers - please help!?!

64

My findings:
I suffer from the same choppy playback since PMP2.20 on my Qnap NAS (TS-451a with firmware 4.3.5.0722, 8GB, no suspicious CPU spikes). I updated both the PMP and the PMS to the latest version. Tried many combinations in the settings, but the “best” one is with hardware decoding on and sync to audio. “Best” means here: chunks of 4 to 8 dropped frames every 5 seconds or so. Unwatchable, it’s a pain!

Just now I tried it on my Win 8.1 PC with PMP2.20.0.909. I played around with hardware decoding on/off and the subsettings, DirectPlay, SyncMode.
Every setting I used just works perfectly!

65

Interesting!

I use a Windows 10 HTPC.

Are you using refresh rate switching, Angle, and sync mode: display?

66

At first: whatever configs I describe below, there are no dropped frames in any of them (besides whilst the first second after start of playback)!

The info overlay says OpenGL: Google Inc Angle (Nvidia
something)

I assume that “refresh rate switching” is the same as “allowDisplayModeSwitching” in the config file and “Display Sync” in the Info overlay (pressing ‘I’ at playback) and “Allow Display Mode Switching” in the UI’s settings window.

What ever I set “Allow Display Mode Switching” to, “allowDisplayModeSwitching” always remains ‘false’. So I changed it manually via an editor to ‘true’.
So my current config looks like this:
“video”:
“allowDisplayModeSwitching”: true,
“cache”: 75,
“debug.force_vo”: “”,
“deinterlace”: false,
“directPlay”: true,
“directStream”: true,
“hardwareDecoding”: “copy”, [in the UI: ‘copy-back’]
“refreshrate.auto_switch”: true,
“refreshrate.avoid_25hz_30hz”: false,
“refreshrate.delay”: 3,
“sync_mode”: “display-adrop”

I’m not watching on a TV set but on an Eizo monitor.
Plex ‘tries’ to change something on playback when the Eizo is set to 60Hz but doesn’t succeed. That leads to some flickering/tearing now and then. However, the Eizo does not switch to 24Hz.
In this configuration the info display says (no difference between TV mode fullscreen and windowed):
“Current mode: #52 1920x1200x32bpp @59.9401Hz”.
“A/V: -0.009” sometimes going down to -0.018
“Display Sync: yes (ratio 2.500)”
“Mistimed Frames: 1/0”
“Measured FPS: 59.9xx” xx means it’s changing around 59.920 and 59.958 or so

When I set the Eizo to 24fps:
“Current mode: (not found)”.
“A/V: 0.000”
“Display Sync: no”
“Mistimed Frames:” doesn’t exist
“Measured FPS:” doesn’t exist

67

@TedStryk Thanks for all of this information, really helpful!

It seems that what you are doing is playing back 23.976 content at 59.94 ish, which is 2.5 times the native frame rate.

I am using a TV as my playback display, and that is capable of switching to 23.976 to more closely match the frame rate of the content. I just tried playing it back at 59.94 and it wasn’t too bad, fairly smooth, apart from fast camera pans, where I could see some jerkiness and stuttering.

If I play the same content back at 23.976, so the video fps matches the frame rate of the TV (almost) exactly, then I get totally smooth playback, no jerky camera pans, and because my TV is capable of that, it seems logical to exploit that option to get the best possible playback I can.

On PMP v2.10 this is working well, and I use Display Sync: vdrop to keep the audio and video in sync for the duration of the film. If I use sync mode: audio, the audio and video gradually drifts out of sync as the film plays.

However, on the more recent version of PMP, this behaviour is broken, the video is playing back like a slideshow, completely unwatchable. As you can’t replicate this, I am guessing that it may be specific to to 23.976 frame rate and display refresh switching.

Hopefully someone from Plex will be along soon to confirm the issue and deliver a fix.

68

Yeah, you’re right but to clarify:
I did set the Eizo manually to 24p (because it doesn’t switch automatically) for the second experiment. The info said:
“Current mode: (not found)”.
“A/V: 0.000”
“Display Sync: no”
“Mistimed Frames:” doesn’t exist
“Measured FPS:” doesn’t exist

and everything was nice to watch, even faster pans.

What I now did is to rearrange my furniture :wink: Coz my HDMI cable is to short to connect the TV to the PC. Now I tried it with my TV (last Panasonic Plasma model) which is able to switch frequencies and did play very well with the old PHT and the same NAS I’m still using.
Result: still no dropped frames but “Mistimed frames: x/y” where x is greater than y! E.g. 300/292.
So yes, awful playback, just like a diashow as you already mentioned.
Forcing the TV to 59.94 and everything plays without freezing again. But that has this artificial look from frame doubling at any movement on the screen. Totally kills the immersion.

Have you ever tried Plex for Kodi?
Let me put back my furniture into place.

69

Ha, thanks for that, very interesting, and yes I had misunderstood a few things first time round.

I have tried Plex for Kodi, and it is a viable alternative, but I really like the PMP interface, and simplicity, and as it is their flagship player, I was hoping I could continue to use it. The mpv engine and new PMP was the reason that I switched from MediaPortal, to become a Plex subscriber.

I am okay for now, as PMP 2.10 is still working, but I fear there will come a day when it stops working. Plus, I am miffed that I am missing out on the new skin customisation options that are available in the newer versions.

70

Hello again, I want to add something. ^^
I’ve tested the “bug” on the embedded platform
(Version PlexMediaPlayer-2.20.0.920-50730a07.Generic-x86_64)
And I can say that the bug is not present there. Yep, it’s working as it should, no lag, no stutter
 perfectly fine playback (GPU Nvidia GT 610 + old AMD Athlon)

Another thing I want to add is the curiosity of mpv in combination with PMP to add some kind of delay at 23.976/24p playback. (roughly +135ms) Regardless of OS. (Windows, Embedded)
The newest version of mpv (standalone) does not add any kind of delay

Another thing the standalone version doesn’t do is dropping frames at 23.976p playback with passthrough enabled.

Updating mpv might also fix old/other problems. :wink:

71

I use embedded everyday on 3 different AV systems with and without an AVR and I don’t experience any sort of lip sync issues with 23.976fps or 24fps content sent out at 23.976Hz or 24Hz. If you want to post your plexmediaplayer.conf file I can take a look.

72

Thanks @Mitzsch for the good info. Plex, any plans to update to the new mpv?

73

yes, sure
plexmediaplayer.conf.txt (3,5 KB)

I already changed the delay value for 23.976/24p playback, but the rest should be fine. :wink:
(and i deleted the clientUUID, no idea if this is an value, that i should share)
Thanks for having a look at it. :slight_smile:

74

Is there a reason why you are using copyback for hardware decoding? Also I see you are resampling the audio to sync with the refreshrate of the display. Is the display a HDTV or monitor?

75

thanks
copy-back is because of some strange behavior with native vdpau and the gt610
audio to sync seems to work great in this setup, but with passthrough its disabled of course
Old HDTV

on my windows setup i have the same issue
with sync set to display and “d3d11va native”

(is it safe to post a clientUUID?)

76

Copy-back negates all the benefits of HW decoding so that is unfortunate. I always use passthrough so Display Sync is set to no for my setups.

77

yeah, its quite unfortunate that I have to use copy-back. :frowning:

So you also have no idea why there is this delay on my setup?

78

You mean why you have to set for 135ms delay? Do you have all the post processing features enabled on the TV? Is there an AVR in the chain?

79

yep, why there is this delay. It’s kinda strange.
There is an AVR in the chain and the TV has some input lag, but the strange thing is. With Kodi and the vanilla version of mpv @23.976p, I don’t have to set any kind of delay.

80

Do you mean audio passthrough? Display sync still works with audio passthrough. Well it does on version 2.10, it obviously doesn’t on newer versions.