madshi bug tracker - madVR
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0000623madVRbugpublic2019-10-30 03:372019-10-31 17:31
meowmeow 
 
normalmajoralways
newopen 
WindowsWindows 10 Education 64 bit1903
v0.92.17
MPC-HC (64bit) 1.8.8 (82efc58f7) by clsid2
LAV Splitter 0.74.1.24-git
LAV Decoder 0.74.1.24-git
Software
none (progressive)
no
On
all modes
NVidia
EVGA 2080 Ti FTW3 Ultra
436.48
0000623: Presentation glitches occur when "after copy to backbuffer" set to "don't flush"
Define SETTING = "after copy to backbuffer" in Windowed Mode under Rendering
Define ACTIONS = "go to fullscreen or jump during a video playback"

With SETTING default to "don't flush", whenever I perform ACTIONS, presentation glitches almost always (95% of the time) occur. However if I change SETTING to "fush" or "flush & wait(sleep)" and repeat the same ACTIONS, presentation glitches NEVER occur.

I have repeated this experiment with a variety of video files, including 720p, 1080p, 2160p, HDR, SDR, and 10bit SDR, all produce the exact same result.

I also experimented with another setting "after D3D presentation" and it has no effect on presentation glitches wether it's set to "don't flush" or "flush" or "flush & wait".

Considering "don't flush" is the current default value for SETTING and that it causes the glitch problem, may I suggest that the default change to "Flush & wait" in future releases? Or will there be any negative effect from that? "Flush" also works but it uses much more CPU (about 7-8% on a 9900k, compared to 1-2% used by "Flush & wait").
Note: the "Decoding" is done by "D3D11" however this option is not avaiable in the drop-down menu below so I list it here. Please ignore my selection below.

My monitor is 144hz, 8bit+FRC. I selected "10bit(or higher)" under devices/properties. In NVidia control panel I have set the display profile to use 144hz, 10bit, RGB, Full.
No tags attached.
png This_is_with_default_setting.PNG (331,862) 2019-10-30 03:42
http://bugs.madshi.net/file_download.php?file_id=319&type=bug
Issue History
2019-10-30 03:37meowmeowNew Issue
2019-10-30 03:42meowmeowFile Added: This_is_with_default_setting.PNG
2019-10-31 05:15meowmeowNote Added: 0002574
2019-10-31 17:31madshiNote Added: 0002577

Notes
(0002574)
meowmeow   
2019-10-31 05:15   
Another observation: if I set the number of frames to be presented in advance to 2, 3, or 6, then I will not need to do flushing at all (all 4 flushing options down below can be set to "don't flush") and will not get any presentation glitch. However any other number of presented frames in advance, including 1, 8, 10, etc., will give me lots of presentation glitch.
(0002577)
madshi   
2019-10-31 17:31   
This is often somewhat "random". Changing the defaults might make things better for you, but could potentially introduce issues for other users.

Anyway, if these glitches only occur if you perform some kind of "action", it's not overly important, anyway. The important thing is that playback is completely smooth while you just sit there and enjoy the movie.