Desync when playing replays in higher tempo

[Kapo]

NAME: see title

DESCRIPTION: While testing, I had several occasions where I looked at a replay at high speed and it desyncs. Watching the same replay at a lower speed solves the issue.

I didnt care at first, but when I started to have desyncs at 8x speed I thought I post a report.

REPRODUCIBILITY: Do not have a super-high-end PC. Watch replays.

SCREENSHOT/VIDEO: none needed

LOG: not sure if necessary. I can provide some to further investigate.

ADDITIONAL INFORMATION: Possible in connection with tight scripted timers.

Edited July 12, 2022 by Kapo

[LEBOVIN]

I wonder if the replay somewhat accumulates timing mismatches when playing it back at a faster speed (especially x16/x32). Maybe at some point is is just too much difference and the desynch message triggers. This would explain why very long maps like Legions (or smth @Emmaerzeh ?) tend to desynch in replays, cause people will not watch them in real time but fast foreward and over the course of 50minute gameplay the margin for desynch might likely be reached.

[Kapo]

I also noticed (one time) that by accident I did a "trick" on the map that required very precise timing, and that was the moment the desync message happened. Maybe with the accumulated error, the replay couldnt re-play this very tightly timed move anymore.

When I replayed the same it in 4x, everything went fine, and it was able to could replicate it, no desync message.

Edited July 12, 2022 by Kapo

[Kubik]

Well on my PC 16x and 32x is no difference both are about 6-14x depending on how much is happening on the screen, and because I have specified vsync and FPS cap (that I am trying to enforce) so unless BF goes crazy (which sometimes happen) it can not go any higher than 16.6x.

Technically there SHOULD NOT be any difference between playing at different speeds, because it just does list of operations, and then checks the timer and waits until next tick when it should do next list.

Desync in replays have nothing to do with longer maps having higher probability of desync, because EA decided to use imprecise math, once the match desync, even if it is for players still not noticeable, the replay might desync too.

And by the way is that on test server? I think replay desync messages did not make it to main server last patch 🤔

If you have replay that is inconsistent early and gives desync messages I would be interested in it, but I do not want to wait half an hour for single test.

[Kapo]

1 hour ago, Kubik said:

If you have replay that is inconsistent early and gives desync messages I would be interested in it, but I do not want to wait half an hour for single test.

Desyncs typically happend at around 4-5 minutes, and replays are not longer then 10-15 total.

As soon as I have one that desyncs again (shouldnt take long), I'll send it to you.

[Kapo]

Today I deleted and re-downloaded all sr- files in pak and pak-test, and the problem doesn't occur anymore for now.

So maybe archived for now, but I'm going to add more details if it comes back again.