View Issue Details
|ID||Project||Category||View Status||Date Submitted||Last Update|
|0000513||madVR||bug||public||2017-10-19 15:28||2018-01-14 12:05|
|OS||Windows 10||OS Version||Fall Creators|
|Summary||0000513: Fullscreen exclusive seek bar kills present queue|
|Description||When 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 Reproduce||Use seek bar in fullscreen exclusive.|
|Tags||No tags attached.|
|Media Player (with version info)||MPC-HC 1.7.13|
|Splitter (with version info)||internal LAV 0.70.2.1|
|Decoder (with version info)||internal LAV 0.70.2.1|
|DXVA2 Scaling Active||no|
|Aero / Desktop Composition||Off|
|Problem occurs with mode||fullscreen exclusive mode|
|GPU Model||980 Ti|
|GPU Driver Version||387.92|
||I just noticed, the playback being slightly stuttery also only applies when not presenting a frame for every VSync|
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.
||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...|