Stutterring but reads 60fps

Did you have the problem only on you Galaxy A7 or on a desktop too? Did you you try remote preview on your Galaxy A7 on different browser?

Remote preview is always about 20% slower on anything I ever try so I almost always create a debug APK to get a better reading.

The janks happen are more common on a lower end device but even on a my fairly high end Huawei Mate Pro I see it sometimes. I even saw it happen on my high end PC a couple of times.

The frustrating thing is that all these devices are running 60fps even when it happens.

FYI Ashley posted a bug report to Chromium Bugs along with a slow motion video of the janking in all its glory.

The bug report and video are here:https://bugs.chromium.org/p/chromium/issues/detail?id=1324177

Thanks Ashley

added my ⭐ to the issue

I just read one of the comments from the Chrome devs:

> For the record, the above test case drops frames in Chrome even on a recent M1 MacBook Pro with high-end CPU.

I saw this too, this gives me hope it fixes my issue on desktop with jitter when vsync is enabled! I have starred it too.

yes please star it, only 7 right now...

I agree, there's a chance this bug affects only Android exports, but judging by the other dev's comment about jank on his modern macbook, it may even affect desktop exports, so it must be in everyone's interest to star this!

Problem is rAF/BeginMainFrame races with webview's draw. Most of the time, rAF loses (expected), but every once in awhile, rAF wins and manages to commit and activate first before draw, it means the previous frame never ends up being drawn. And then the next rAF goes back to losing which means the next draw ends up drawing the same frame from rAF. This behavior is webview-only (afaik).