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IDProjectCategoryView StatusLast Update
0000513madVRbugpublic2018-01-14 12:05
ReporterLarwood Assigned Tomadshi  
Status assignedResolutionopen 
OSWindows 10OS VersionFall Creators 
Summary0000513: Fullscreen exclusive seek bar kills present queue
DescriptionWhen in fullscreen exclusive mode whenever you mouse over to make the seek bar appear the present queue will drop to 1-2/2. This also causes playback to be slightly stuttery, although no frames are dropped. Seems to happen regardless of the format being played, and regardless of using DXD11 or DXD9.

Has the additional side-effect of causing playback to momentarily speed up and slow down when the seek bar is shown or hidden, if using D3D11 without "present a frame for every VSync."
Steps To ReproduceUse seek bar in fullscreen exclusive.
TagsNo tags attached.
madVR Version0.92.7
Media Player (with version info)MPC-HC 1.7.13
Splitter (with version info)internal LAV
Decoder (with version info)internal LAV
Deinterlacingnone (progressive)
DXVA2 Scaling Activeno
Aero / Desktop CompositionOff
Problem occurs with modefullscreen exclusive mode
GPU ManufacturerNVidia
GPU Model980 Ti
GPU Driver Version387.92



2017-10-19 15:31

reporter   ~0001865

I just noticed, the playback being slightly stuttery also only applies when not presenting a frame for every VSync


2017-10-20 11:40

administrator   ~0001866

The present queue size is intentionally limited to 2 frames as soon as any user interface is displayed which supports user interaction. The reason for that is that a big full present queue automatically results in increased user interface latency. Latency doesn't matter at all during video playback. But if the user interface takes a full second to react to anything you do, that would feel rather bad.

Of course stuttering is not a good thing, either, maybe I can improve that. Or maybe I should reduce the queue size to 3 instead of 2, maybe that would already solve the problem (although increasing latency again).

Playback speeding up without "present a frame for every VSync" probably depends on the GPU driver implementation. I'm not sure if I can change that.


2018-01-14 12:05

administrator   ~0002009

FWIW, I've just noticed that the "low latency" mode runs smoothly on my AMD GPU but does stutter on NVidia, for some reason. I'll have to investigate why that happens. Should be something fixable, I suppose...

Issue History

Date Modified Username Field Change
2017-10-19 15:28 Larwood New Issue
2017-10-19 15:31 Larwood Note Added: 0001865
2017-10-20 11:40 madshi Note Added: 0001866
2017-10-20 11:40 madshi Assigned To => madshi
2017-10-20 11:40 madshi Status new => assigned
2018-01-14 12:05 madshi Note Added: 0002009