PTB beta “Dancersizing, Grey & Hopeless” release 2012-11-11


Psychtoolbox-3/Psychtoolbox-3@9b5c6901 at GitHub tag: PTB_Beta-

This is mostly a bug-fix release, but it also improves GetChar support on some platforms.

All systems:

  • GetChar, CharAvail, FlushEvents and ListenChar now (ab)use keyboard queue functionality on setups where use of Java based GetChar et al. is ineffective or impossible: This should enable useable support for Windows Vista, Windows-7, Windows-8 (untested), Matlab in -nojvm mode, and for GNU/Octave in its standard terminal command line interface mode, and the GUI which will be part of the next major Octave release. Now this mode will use keyboard queue functionality, which means it doesn’t work if your code already makes use of keyboard queues. More specifically: On Linux it will block access to the keyboard queue of the default keyboard, all other queues will work. On Windows it will block access to all keyboard queues, but allow use of the “keyboard queues” to query mice, joysticks and other non-keyboard devices. On OSX it will block all use of keyboard queues, because there is only 1 queue, as opposed to Linux/Windows which can have many parallel queues. Otoh, code that explicitely uses keyboard queues will have a more flexible and powerful interface to keyboards anyway. GetChar et al. are just for simple and convenient keyboard access, and mostly to keep old code working, so this shouldn’t be much of a limitation.

  • CRS OptiCal support by Andreas Widmann, Uni Leipzig. The OptiCal() function allows reading measurements from a CRS OptiCAL luminance meter connecte to a serial port.

  • Various other small improvements.

  • PsychPortAudio: Now reports ElapsedOutSamples more precise, even in some corner-cases where that count could be off by up to a millisecond in the past.

  • Some audio demos have been improved, ie., cleaned up, to show best practices for the current driver instead of the stuff that was considered optimal 2 years ago. The old code of course still works perfectly with the current driver, but sometimes did unneccessary complex stuff that is no longer needed for the current driver. PsychPortAudioTimingTest now also adapts a bit better to the kind of large latencies required to make shoddy MS-Windows setups work.

  • IOPort: If async background data reception is used, e.g., to automatically receive and timestamp trigger bytes from a serial port, and a read timeout occurs, e.g., the trigger source hasn’t been started within the max 25 secs timeout, then the driver will return an empty [] packet, instead of one that is filled with zeros. The old behaviour was confusing, this one now behaves in async mode as it would behave in sync mode.


  • PsychGPUControl: Can now also automatically disable 3D desktop composition on Ubuntu Linux 12.10, at least when the Unity interface is active. So far it was incompatible with 12.10 and did nothing. However, the general recommendation is still to manually disable any kind of 3D desktop compositor on experiment machines, regardless what OS you use. It avoids possible confusion if the automatic fails - which can happen on both Linux and Windows under some circumstances without PTB noticing this, and helps performance in any case, because even a compositor on standby will use more valuable graphics resources and cpu/memory than a disabled compositor.


  • Screen: Videocapture should now also work with 64-Bit Octave on OSX, not only with Matlab.