RESOLVED: 22580 - lots of jitter at 30 fps

Bugs
1

Hi,

It feels the real time mode suffers from a lot of jitter, compared to 13064 (and probably 13770).
Sometimes too fast, sometimes too slow.

I’ve attached a super simple showing the issue.
13064, it feels smooth (well, less smooth than 60 fps of course, but as smooth as it can for a sliding color block with no motion blur at 30 fps)
22580, lots of jitter.

Could this have to do with some drivers options? vysnc and so on?

Thanks
Vincent
ramp.toe (3.88 KB)

2

It’s interesting that 22580 exhibits this more than 13770 in this case but what’s happening here is because 30fps content is being show on a 60hz display. This means that each frame can be shown for 1, 2 or 3 frames (16->50ms in time), which means the line stays put for a long period sometimes and a short period other times. This type of content really highlights this issue, but any sort of smooth movement can have it. The same is true on my 120hz display: showing 60fps content looks horrible, but if I turn down the display to 60hz then the content looks perfect.
To fix this you can either set the environment variable TOUCH_DOUBLE_DRAW=1 or use the Nvidia control panel and set the Vertical Sync to ‘Adaptive, Half refresh rate’.

3

I’ve added a new ‘FPS is Half Monitor Refresh’ parameter to the Window COMP which is a nicer way of dealing with this case than using the env var.

4

I’ve tested the various options, but I feel I got better result without any tweaks with build series 13xxx.

‘FPS is Half Monitor Refresh’ is only meant for full screen output covering everything right? Windows in the background went crazy and it eventually crashed.

I’ll investigate more when I have the time.

Just saw there was some interesting info on the wiki.
derivative.ca/wiki088/index. … d_Playback
derivative.ca/wiki088/index. … al_Tearing

Thanks Malcolm.

5

Yeah, it’s likely that 13xxx showed different results, but under the right conditions it would still suffer from the same issue.

The FPS is Half Monitor Refresh should work for all cases, but that’s good info that it fails for you in that case. Can you give more details about your setup so I can try to reproduce/report to Nvidia?

6

Bumping this one, looks like with the new nvidia drivers (340.66) the FPS is Half Monitor Refresh checkbox has no effect anymore, I get jitter at 30fps.

Going to revert to an older version and check.

7

Yes with 333.11 it’s fine, though these ones have the memory leak with spout.