[manhas]

I'm using NFS as protocol, wired network, Kodi Beta 1, adjust playback to display and a judder feature on my TV to help with 24p judder. Playback is smooth and judder free except when this issue (rarely) occurs.

The choppiness is not a lot but enough for it to be disturbing, when it starts it's very noticeable in moving or panning scenes. It's not an even/regular choppiness that could come from judder or a frame pulldown, it looks more like choppiness from performance issues.

It happens at random and does not appear to be related to a certain bitrate or resolution, e.g. one time it started in the middle of a 40 minutes episode after I've just watched 2 hours of similar video before that, and yesterday the choppiness started 90 minutes or so into a movie.

Once the choppiness start it won't go away unless I stop the video and start it again, not sure if I've also had to restart Kodi for it to go away. So far I've just seen it happen 2-3 times after looking at around 30 hours of video, so it doesn't occur often and it will be hard for me to create a debug log for it.


Have anyone experienced the same thing? Could there be a background task or something that either TVOS or Kodi start that affect the video playback?

[manhas]

I've been using the Kodi 17 betas for a while now and the issue persist with all the versions I've tested, but I've also (kind of) discovered how trigger it and also how to quickly "fix it".

The easiest way to trigger the choppiness is to skip forward/backwards a couple of times. Quite often the video start to play with a noticeable choppiness after this, but sometimes the playback is choppy already when video is first started but this is more rare. When the playback is choppy all it takes is to skip backwards once (e.g. 10 seconds) and the playback will be normal again.

I remember it kind of worked the same way on OS X with the MacMini 2010 horizontal tearing issue I had with Kodi 16 before that bug was fixed. If you skipped forward/backwards the video would play with horizontal tearing every other time you skipped, if it started to tear it was enough to skip one more time to have the tearing go away.

[DanTheMan827]

Could you please verify if this still occurs in the latest Apple TV build?

I too have experienced something similar to what you're describing and haven't experienced it at all since hardware acceleration was added for h.264 content

[manhas]

Yes, I'm still having some kind of choppiness issue with the latest Apple TV build when using hardware acceleration, but it's not the same kind.

Without hardware acceleration the choppiness is very noticeable but it's predictable and easy to fix. I would say it occurs every 3-5 attempt when I do a play/pause or when I skip the video. The choppiness is even and continues and it's impossible not see it when it starts. But it's always (at least 9 of 10 times) possible to make it play smooth again by skipping forward/backward one step.

With hardware acceleration there's a different kind of choppiness. It's more a subtle but noticeable jerk in the playback that occurs perhaps once every 10 to 20 seconds (seems to be random). So it's harder to detect and usually it requires a couple of times before I'm certain that it's actually happening. It won't go away with play/pause or if I'm stepping in the video, the only way I've managed to get rid of it when it occurs is to exit the video and start the playback again. Sometimes I need to start the video a third or fourth time before the playback is smooth again.


So currently I'm not using the hardware acceleration, it's easier and quicker to fix the choppiness when not using it. And since the choppiness is not as obvious with hardware acceleration turned on I find myself looking for jerkiness every time there's a panning view instead of enjoying the movie I'm watching.

[Memphiz]

debug log (wiki) for the hw acceleration case please

[manhas]

Took me sometime to get back on this, I've been enjoying Kodi instead debugging it the last few months.

Anyway, the issue is still there for me and I'm no longer sure if there is any difference between using VTB and when using the software decoder. I've been using hardware decoding the last 3 months and it behaves pretty much the same as before when I didn't use it.

As mentioned it appears to be related to play/pause and skip backwards/forward. I have the AutoSubs add-on active, so most of the time when I start a movie or episode the video will pause and the subtitle window is shown. This result in choppiness when the video is resumed 9 times out of 10. It's the same when I skip forward or backwards, it's a gamble every time if the playback is choppy or smooth when the video resumes.

I rarely watch movies, so I haven't tested with many videos longer than 60 minutes. But the 2-3 times I've watched a full length movie the last few months, the choppiness have started in the middle of the movie during playback, without any pause or skipping. So it appears the issue can occur by itself if the video is playing long enough.

In all cases when the video is choppy, I can get smooth playback again by skipping backwards one or two times.


Here is the debug log when the choppiness occurred after AutoSubs paused the video and opened the subtitles window when starting a video:
http://paste.ubuntu.com/24150565/

Build: 17.0 Git:2017-03-04-04876e8-dirty
Sync playback to display: YES
VTB Decoder Enabled: YES
Screen refresh rate: 60Hz
Network: Wired NFS, same result with wired SMB
CPU/FPS: No difference when it's smooth compared to choppy

[manhas]

Bumping this thread to see if anyone else is experiencing anything similar at all? The choppiness is subtle but noticeable, so one wouldn't need a "trained eye" to see it. But since I haven't seen any other reporting similar issues I'm starting to question if the issue is somewhere in my own setup and not in ATV4/Kodi.

[manhas]

An update to the issue.

I've changed from the VTB Decoder to the AVFoundation hardware decoder and the issue went from happening at least once for every started video to not a single time so far with the AVFoundation decoder. 

It's been almost two weeks, I've probably played 20-30 different videos and I've even tried to stress the video player with play/pause/skip/rewind etc. and still no choppiness in sight. I don't want to say it's resolved prematurely, but so far it loks like the AVFoundation decoder fixed the choppiness issue I had.