Hi,
I am trying to run EyeLink Demo, usually, I get the messages as below a few times, then I get the demo running. But somehow, recently, I can't run the demo anymore, just keep getting the messages as below.
As suggested, I add Screen('Preference', 'SkipSyncTests', 1) to my script, not work as well.
I tried it on two machines, both can run at the beginning for some times, then after some point, no screen anymore.
one machine, I use 32bit 2012 version of matlab on win xp, the other I use 2015 64bit matlab on win7.
Thanks a lot for any suggestions.
Li
-------------------------------------------------------------------------------------------------------------
Messsage:
PTB-INFO: Multi-display setup in explicit multi-display mode detected. Using the following mapping:
PTB-INFO: Screen 0 corresponds to the full Windows desktop area. Useful for stereo presentations in stereomode=4 ...
PTB-INFO: Screen 1 corresponds to the display area of the monitor with the Windows-internal name \\.\DISPLAY1 ...
PTB-INFO: Screen 2 corresponds to the display area of the monitor with the Windows-internal name \\.\DISPLAY3 ...
PTB-WARNING: Screens 1 and 2 do have non-equal width and height. This will probably cause wrong behaviour
PTB-WARNING: when trying to open a fullscreen window on Screen 0 that is supposed to fully cover displays 1 and 2.
PTB-WARNING: In that case, either change your screen settings to matching size and refresh rate in the display control
PTB-WARNING: panel and retry after a 'clear all', or manually specify a [rect] parameter for the window in the
PTB-WARNING: Screen('OpenWindow', 0, [color], [rect]); command to manually enforce creation of a proper onscreen window.
PTB-WARNING: Startup test of beamposition queries for high precision timestamping detected problems on your graphics card + driver combo.
PTB-INFO: Seems beamposition queries are unsupported whenever the display is in a vertical retrace state.
PTB-INFO: I will enable a work-around which should satisfy the timing needs of most applications, ie.
PTB-INFO: robust and jitter-free deterministic timestamps. However, all reported timestamps may have a
PTB-INFO: constant offset of up to the duration of the vertical blanking interval (max 1 msec worst case)
PTB-INFO: of your display. Read 'help BeampositionQueries' on how you can remove that bias by some manual
PTB-INFO: intervention, should you need that last bit of accuracy. A second drawback is increased cpu load,
PTB-INFO: which may cause louder air-fan noise due to heat production and lower battery runtime of laptops.
PTB-INFO: This is Psychtoolbox-3 for Microsoft Windows, under Matlab 32-Bit (Version 3.0.10 - Build date: May 22 2013).
PTB-INFO: Type 'PsychtoolboxVersion' for more detailed version information.
PTB-INFO: Most parts of the Psychtoolbox distribution are licensed to you under terms of the MIT License, with
PTB-INFO: some restrictions. See file 'License.txt' in the Psychtoolbox root folder for the exact licensing conditions.
PTB-INFO: The detected endline of the vertical blank interval is equal or lower than the startline. This indicates
PTB-INFO: that i couldn't detect the duration of the vertical blank interval and won't be able to correct timestamps
PTB-INFO: for it. This will introduce a very small and constant offset (typically << 1 msec). Read 'help BeampositionQueries'
PTB-INFO: for how to correct this, should you really require that last few microseconds of precision.
PTB-INFO: Btw. this can also mean that your systems beamposition queries are slightly broken. It may help timing precision to
PTB-INFO: enable the beamposition workaround, as explained in 'help ConserveVRAM', section 'kPsychUseBeampositionQueryWorkaround'.
PTB-INFO: OpenGL-Renderer is NVIDIA Corporation :: GeForce 8800 GT/PCIe/SSE2 :: 3.3.0
PTB-INFO: VBL startline = 900 , VBL Endline = 900
PTB-INFO: Measured monitor refresh interval from beamposition = 16.697947 ms [59.887602 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 16.686411 ms [59.929003 Hz]. (295 valid samples taken, stddev=0.349326 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 16.666667 ms [60.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
WARNING: Couldn't compute a reliable estimate of monitor refresh interval! Trouble with VBL syncing?!?
----- ! PTB - ERROR: SYNCHRONIZATION FAILURE ! ----
One or more internal checks (see Warnings above) indicate that synchronization
of Psychtoolbox to the vertical retrace (VBL) is not working on your setup.
This will seriously impair proper stimulus presentation and stimulus presentation timing!
Please read 'help SyncTrouble' for information about how to solve or work-around the problem.
You can force Psychtoolbox to continue, despite the severe problems, by adding the command
Screen('Preference', 'SkipSyncTests', 1); at the top of your script, if you really know what you are doing.