Hi all,
I had been having trouble with some stimulus triggers for my EEG setup with the ViewPixx / Neuroscan NuAmps setup I have, so I tried updating Psychtoolbox. Now I have a host of problems I didn't have before, and my triggers still aren't reliable.
Main problem: Psychtoolbox reports synchronisation failure where it didn't before:
PTB-INFO: OpenGL-Renderer is ATI Technologies Inc. :: ATI Radeon HD 5770 OpenGL Engine :: 2.1 ATI-1.24.39
PTB-INFO: Renderer has 1024 MB of VRAM and a maximum 1001 MB of texture memory.
PTB-INFO: VBL startline = 1080 , VBL Endline = 1123
PTB-INFO: Measured monitor refresh interval from beamposition = 16.667300 ms [59.997719 Hz].
PTB-INFO: Will use beamposition query for accurate Flip time stamping.
PTB-INFO: Measured monitor refresh interval from VBLsync = 8.333857 ms [119.992460 Hz]. (50 valid samples taken, stddev=0.084366 ms.)
PTB-INFO: Reported monitor refresh interval from operating system = 8.333333 ms [120.000000 Hz].
PTB-INFO: Small deviations between reported values are normal and no reason to worry.
WARNING: Mismatch between measured monitor refresh intervals! This indicates problems with rasterbeam position queries.
----- ! PTB - WARNING: SYNCHRONIZATION TROUBLE ! ----
One or more internal checks (see Warnings above) indicate that
queries of rasterbeam position are not properly working for your setup.
Psychtoolbox will work around this by using a different timing algorithm,
but it will cause Screen('Flip') to report less accurate/robust timestamps
for stimulus timing.
Read 'help BeampositionQueries' for more info and troubleshooting tips.
LoadIdentityClut: Warning: GPU low-level setup code for pixel passthrough failed for some reason! Using fallback...
LoadIdentityClut: ATI Radeon HD-5000 Evergreen on OS/X detected. Using type-2 LUT.
I'm using MATLAB R2012b on Mac OS 10.9.5.
Second problem: The "DrawText" function doesn't want to work properly:
PTB-WARNING: DrawText: Failed to load external drawtext plugin [dlopen(/Applications/Psychtoolbox/PsychBasic/PsychPlugins/libptbdrawtext_ftgl64.dylib, 10): Library not loaded: /opt/X11/lib/libfreetype.6.dylib
Referenced from: /Applications/Psychtoolbox/PsychBasic/PsychPlugins/libptbdrawtext_ftgl64.dylib
Reason: Incompatible library version: libptbdrawtext_ftgl64.dylib requires version 19.0.0 or later, but libfreetype.6.dylib provides version 10.0.0]. Retrying under generic name [libptbdrawtext_ftgl64.dylib].
PTB-WARNING: DrawText: Failed to load external drawtext plugin 'libptbdrawtext_ftgl64.dylib' [dlopen(libptbdrawtext_ftgl64.dylib, 10): image not found]. Reverting to legacy text renderer.
PTB-WARNING: DrawText: Functionality of Screen('DrawText') and Screen('TextBounds') may be limited and text quality may be impaired.
PTB-WARNING: DrawText: Type 'help DrawTextPlugin' at the command prompt to receive instructions for troubleshooting.
Neither of these problems are ones I had before updating Psychtoolbox.
With the triggers, I suspect it is a problem with flip timing, but I've tried everything without success so far. My code for the triggers is taken pretty much straight out of the DataPixx demo code:
Datapixx('StartDoutSchedule');
Datapixx('RegWrVideoSync');
[vbl, ~, ~, Missed] = Screen('Flip', w, vbl + waitduration);
Datapixx('StopDoutSchedule');
Datapixx('RegWrRd'); % Update registers for GetDoutStatus
status = Datapixx('GetDoutStatus');
Datapixx('SetDoutValues', 0);
Datapixx('RegWrRd');
waitduration is defined as ifi*.8, so the flip doesn't miss - I tried ifi/2, but that cause too many misses.
Any help would be greatly appreciated. I'm supposed to be piloting this experiment tomorrow, and I'm kind of desperate.
Thanks
Deborah.