Just to be more precise here… These “frame drops” I can see as well, but they’re not frame drops or actual frame skips when it comes the video player debug overlay or the debug logs. E.g. with external SRT subtitles, these short stutters are not reflected in the debug overlay at all which makes it quite hard to nail down the issue. It purely comes down to seeing them. And this is not trivial with all titles either… With some PGS subtitles you can only see it once or twice during the whole movie, with other samples it can be seen with every single subtitle image being shown. The same applies to SRT subtitles. With some, the stutter shows with every single line of text, with others it’s a lot more rare.
Yes those slight frame drops are only seen by the eye. No log ever caught that, We actually had a long topic about that. And the only thing that really helps minimize or even solve the problem is setting dirty regions to 0, which disables it. Makes sense since the whole screen is always rendered, the appearence of subtitles would then be nothing else than anything else that would appear within the content on the screen.
The consequences of that were also known in that regard, that even in idle there would be constant rendering, higher load and higher temps.
That is where smart redraw was supposed to come in by succeeding dirty regions, However, dirty regions still seems to be around for playback, otherwise dirty region 0 in advanced settings would have no effect… and certainly would not create those high idle temps because that is where the new smart redraw comes into play right?
So my conclusion is, that either there is a bug that disables smart redraw if you disable dirty regions manually… or that smart redraw is actually still „kind of“ depending on dirty regions and therefore would also not work if dirty regions is disabled.
Since we had some threads about subtitle performance, the issue always coming up here and then and it being so closely related to rendering, I though this might be worth investigating.
Absolutely worth investigating. Will test your approach myself as soon as I’ve got time for it.
Wanted to make this point clear though so we don’t have to discuss about the issue not being visible with other users again… If you don’t see the issue with current settings, then it won’t help to test this very much in the first place (except maybe for regressions).
This might also be related to the CPU governor and it not reacting in time. Disabling DRR simply keeps us at higher clocks for longer…
Tested this with the sample here that shows the issue most prominently (complex PGS subtitles) - a UHD Avatar clip - and the issue persists. Will test with SRT subtitles as well.
Well I used an empty advanced settings for the past 1.5 years and the subtitles were the only real issue I ever had with the Vero 4k. Others had the same issue here:
It never really resolved until I added the dirtyregions 0 setting in late August. And I saw on other forums, that this was the only workaround that anyone could find.
So I used that the last two weeks and was impressed by the much better subtitle performance. However I then noticed the significantly higher idle temp. Which is per se also not surprising because that is what should happen with no dirtyregions… however since Leia we have smart redraw and the question came up why it seems to be not working with dirtyregions diabled… or why the disabling dirtyregions still has an effect and is not really retired?
In other words: the whole thing is new and a total black box and the solutions I found have downsides. I wanted to post it here first because I know you guys would listen and maybe also have the knowledge or the onnections to investigate.
Well I only use SRT and the issue is most prominent in two cases:
- Subtitles rendered for the first time
- Subtitles rendrered after a longer pause with no dialogue
The issue is quite non existing with continious dialogue.
With dirty regions disabled, I don‘t have the issue anymore at all.
Here some extra reference:
Look at Post #14 for the symptoms, it is 100% the same for me and my Vero 4k
And Post #22 that really only disabling dirty regions is a solution… also mentions smart redraw doing nothing for him when dirty regions is disabled.
Anyway regardless of the issue being 10 months old, it still persists without mentioned dirty regions workaround and the higher idle temps.
I know it is more a Kodi thing than an osmc thing (since users of libreelec, corelec etc have the same problem) but truth is, subtitle users seem to be a minority and have not much of an lobby and the issue always seem to end nowhere when asked on the Kodi forum by a simple user.
If you can replicate the problem, I would appreciate if you may investigate because I think you have a better connection than my lowely ass, lol
Other question: Is an idle temp of 79 degrees acceptable in your eyes? Things have cooled down in Germany alot, room temperature is just 21 degrees but it was 30+ just a month ago and that would easily push the idle temp past 85 degrees in the summer. With nothing in advanced settings and smart redraw being by default active in osmc, idle temps are around 60 degrees. I have the most basic Kodi setup, Estuary skin and only use it to play my files via synology nas… not a single fancy addon is installed… so itvreally is only the disabled dirty regions and somehow then also not working smart redraw pushing the idle temps that high.
We are only having that default on the Vero, correct?
With those test files I can indeed see an improvement - the 23.976fps file shows one stutter when when the activated SRT subtitle shows up the first time. It doesn’t stutter with DR disabled.
The approach doesn’t help with 4K PGS subtitles like with our Avatar sample though.
I never use PSG… I even quickly download STR when the file only has PSG. So I really can only speak for SRT and as you found out, disabling dirty regions helps.
So with that established, please have a look what this change does otherwise, especially since on my Vero 4k I then notice mentioned huge spike in idle temps. That kind if points towards smart redraw being affected.
The question is, can one have dirtyregions disabled and still have acceptable idle temps. That is the mentioned black box that smart redraw is for me, I have no clue how it relates to dirtyregions or if it is even dependend on it.
On my backup box (Mecool M8s Pro+, also s905x with 2/16) running coreelec, I witness less of a spike in temps with dirtyregions disabled… though the comparison is not really great because it is obviously a different (thermal) design. But I thought it might be worth noting.
I run a Vero4k (not plus) and probably 80% of the content I watch has subtitles. I certainly haven’t noticed any frame drops, skips or otherwise anything untoward …
Most of it is 480p, 570p or 720p if that makes a difference.
I don‘t think the Vero 4k has a problem on lower resolutions. I have not tested such low resolutions but the problem exists as chillbo has confirmed.
Don‘t get me wrong, it is not a freeze just a slight frame drop. And it also only happens when 1) subtitles are rendered for the first time or 2) after a longer pause if subtitles (no dialogue for some time). The frame drop feels kind of like the old issue with 24p when there was one frame dropped every 41 seconds when a player didn‘t support 23.976fps (remember the old WD TV?). Some people never ever noticed that because it is just one frame, others are highly sensitive to it.
Anyway, the issue is there but the actual question is, what is going on with dirtyregions and smart redraw. As smart redraw is a new Kodi 18 feature, you can‘t find much about it. It is supposed to reduce load and temps in idle but it does not seem to work with dirty regions disabled. At least that is my conclusion when looking at the temps.
I would gladly live with the dirty regions disabled workaround but only the temps in idle are managable.
OK. I’ll keep a lookout anyway …
That’s exactly why I posted my initial comment here… The issue does exist even though not everyone has noticed/spotted it. We shouldn’t get into discussing whether it actually exists again.
We’re thinking of ways to debug/tackle this issue in the team.
Awesome, thank you. Please keep us informed
I’m not claiming the problem doesn’t exist. Just that I haven’t noticed it. And while I’m not hugely worried about a glitch now and then, I do usually notice them I think …
I would welcome if we could focus on the issue as well, meaning looking into a solution and/or making the workaround solution (disabling dirtyregions) viable regarding idle temps.
Also I think the entire community would benefit if the whole dirtyregions vs smartredraw issue is finally clarified.
I’m glad to hear someone is still looking at the subtitle frame-skip issue. I’ve been following this for a while - I think it was probably me who originally uploaded that Avatar clip.
There’s one other situation where subtitles can cause major problems, and that’s on 4K/60fps material. That may or may not be the same issue, of course. I’ve got a 2 minute clip of “Billy Lynn’s Long Half-Time Walk” which can skip like crazy with subtitles on - you can lose over 300 frames in 2 minutes.
There are two particularly odd aspects to that one. The first is that with subtitles on it skips even where there are no subtitles actually visible on the screen. The second is that it’s strangely non-deterministic - you can play the same clip twice, and it might skip 12 frames the first time and 150 the next.
The lack of reproducibility suggests to me that it’s something quite low level that’s causing the issue, maybe even a hardware issue - fluctuating GPU clock speed, maybe.
Anything new on this issue?
I’ve noticed this recently on some 4K HDR files with SRT.