[Nanomani]

I found what makes videos with subtitle stutter with nvidia shied every time.

in Settings / services => UPnP / DLNA => if "Enable UPnP support" is TRUE
"Share my libraries" must be set to FALSE

To reproduce this issue:

in Settings / services => UPnP / DLNA

=> "Enable UPnP support"  True
           "Share my libraries" True
                   - annouce libary update True
                   - look for external subtitles True
                   - look for remote UPnP players True
 
1 - launch a video with subtitle
2 - wait ~30 mintutes  (seems wait a buffer full ...)
3 - you must see the video stutter

I don't know which sub category in "Share my libraries" make this issue. 
But if each one is enable before, disable each one change nothing
The only ways is to disable "Share my libraries" to stop stutter

For be quiet I have disable completely UPnP support   
maybe it will save someone time ...

[Martijn]

One of our members had some device (a radio) spamming the network with UPNP data. Removing that device from the network solved his issue.

[Nanomani]

One of our members had some device (a radio) spamming the network with UPNP data. Removing that device from the network solved his issue.

 The only device with UPNP enable is my ADSL box.
I will make the test with UPNP disable on the ADSL Box and share the result.

Thanks for the advice.

[da-anda]

That member was me. In my case turning off "share my libraries" did not solve the issue. Only disabling UPNP entirely did help in my case (this setting was added because of my issue). Or ofc unplugging the radio, which causes a huge flood of UPNP traffic. I monitored the network traffic via the tool "wireshark" and found that my radio is sending like 4 (or more) UPNP notifications every second - some of them being duplicates (one triggered by their UPNP layer, one triggered by the underlying UPNP lib they use).

In my case video not only began to stutter after a couple minutes, but picture froze entirely while audio kept playing (if I remember the issue correctly)

[Nanomani]

That member was me. In my case turning off "share my libraries" did not solve the issue. Only disabling UPNP entirely did help in my case (this setting was added because of my issue). Or ofc unplugging the radio, which causes a huge flood of UPNP traffic. I monitored the network traffic via the tool "wireshark" and found that my radio is sending like 4 (or more) UPNP notifications every second - some of them being duplicates (one triggered by their UPNP layer, one triggered by the underlying UPNP lib they use).

In my case video not only began to stutter after a couple minutes, but picture froze entirely while audio kept playing (if I remember the issue correctly)

Whaou ! "picture froze" indeed it was a big issue. If disabling UPNP entirely  was added from your issue. no regrets we are 2 now
I have turn off my ADSL Box to be sure. The issue is gone with all UPnP service enable in settings KODI.

[CiNcH]

Video playback on Android TV indeed can easily get disturbed by some background work. Hope that @peak3d's mediacodec_async approach will help that a bit.

[mik64]

Video playback on Android TV indeed can easily get disturbed by some background work. Hope that @peak3d's mediacodec_async approach will help that a bit.

Thanks Cinch!
is this commit in the last nightly?
or is better to wait few days?
thanks again

[mik64]

That member was me. In my case turning off "share my libraries" did not solve the issue. Only disabling UPNP entirely did help in my case (this setting was added because of my issue). Or ofc unplugging the radio, which causes a huge flood of UPNP traffic. I monitored the network traffic via the tool "wireshark" and found that my radio is sending like 4 (or more) UPNP notifications every second - some of them being duplicates (one triggered by their UPNP layer, one triggered by the underlying UPNP lib they use).

In my case video not only began to stutter after a couple minutes, but picture froze entirely while audio kept playing (if I remember the issue correctly)

thanks da-anda for the hint, but i think it's not my case, if you mean UPNP support in kodi settings: in my service page it's already not enabled...
or is there something else i should see and check?
now, as Cinch suggested few days ago, i'm on the 2018.09.18 nightly build and it works without flaws, at least for me
thanks again

[da-anda]

thanks da-anda for the hint, but i think it's not my case, if you mean UPNP support in kodi settings: in my service page it's already not enabled...
or is there something else i should see and check?

I meant the "enable UPNP support" setting in v18 (which was not present in v17 and older). If that is already disabled for you, then it's a different issue to mine.

[mik64]

thanks da-anda for the hint, but i think it's not my case, if you mean UPNP support in kodi settings: in my service page it's already not enabled...
or is there something else i should see and check?

I meant the "enable UPNP support" setting in v18 (which was not present in v17 and older). If that is already disabled for you, then it's a different issue to mine. 

 yes, it should be some other issue, 'cause it's already disabled.
tomorrow i've time to try to set  for a log...i think it will take some time, for me, because it's the first time i do it...

[mik64]

hi!
today i made a clean install of the last nightly build (kodi-20181020 master armeabi) and tried to reproduce the issue with logging enabled
i have to admit that with loggin enabled the video was more stuttering than ever...anyway here is the log:
hecerexofi (paste)
i didn't any change to the kodi installation
please, tell me if i need to do something different, if necessary
thanks!

[CiNcH]

Enabling debug logging pretty much kills video timings, at least on slower Android devices. I don't think that it is very well suited for debugging stuttery playback, also see this thread.

[da-anda]

component logging will likely kill playback on some weaker devices, but only enabling debug logging should IMO not

[eskimo68]

This still seems to be the best thread for subtitle video stuttering playback so I will post here instead of opening up a new one.

(spent most time solving this here though https://forum.libreelec.tv/thread/10699-...rendering/ )

I've spent several days for months trying to solve the stutter with everything found and there is only one thing that actually mattered, but not enough.

Log:
https://paste.kodi.tv/nedejitugi

(if I should enable certain component logging, tell me - BTW, I hate the colouring in these selections, hard to know if things are selected or unselected)

My own findings:
Note, this is a really old Raspberry Pi (like A or B original version)!
Krypton has no stuttering (but some other sound codec issues which is the reason I upgraded in the summer of 2020).
Nothing has helped (obviously), spent most time in resolution/whitelist, display refresh rate and the advancedsettings.xml config file.
CPU goes up to 100% when stuttering happens.
Doesn't really matter if I'm 720 or 1080 or whatever.
With most of the fixes I've tried CPU is 50%+ at idle and 90% in video pause.
Overclocked from 700 to 800 (obvious first solution), helped at times, sometimes I got no stutter for entire reboots (several hours), temp at maybe 65C (no overclock, 57C).
Obviously overclocked to 900 just to test it, temp 68-72C, but stutter got MUCH worse (continuous). Weird. Not overheated really though? No idea why.
Yesterday I clocked back to 700 and things got A LOT better. Still some stutter but rare enough that I don't mind (too much ).

Huh? Could it be the automatic overclocking (force_turbo, LibreElec) takes more than it gives?
Or is my good old box simply at the end of it's life span (ARM-wise)? Kinda liked to have a miniLinux that does what it should .

End question:
Spent a ridiculous time on this. Should I just hope getting a Raspberry Pi 4B would solve everything and it's really not a software issue?
Since I like Kodi I don't want to go back, really. Was on OSMC in the beginning.
In any case, I either get this solved, try some other build or stay on Kodi (and finally send off some XRP because it really is good software, tyvm).

[eskimo68]

Update:
Got fed up and bought a raspberry pi 4 model B. 
No problems since (CPU stays way lower).

Guess the original model just couldn't cut it with all the "code improvements" and stutter was 100% load CPU-based.