Psychtoolbox interfaces between Matlab or Octave and the computer hardware. The PTB core routines provide access to the display frame buffer and color lookup table, reliably synchronize with the vertical screen retrace, support sub-millisecond timing, expose raw OpenGL commands, support video playback and capture as well as low-latency audio, and facilitate the collection of observer responses. Ancillary routines support common needs like color space transformations and the QUEST threshold seeking algorithm.

Psychtoolbox has many active users, an active forum, and is widely cited. PTB-3 is based on the deprecated Psychophysics Toolbox Version 2 with its Matlab C extensions rewritten to be more modular and to use OpenGL on the back end. The current version supports Matlab R2012a+ and Octave 3.8 and later on Linux, and Octave 6 on MacOSX, and Windows.

Psychtoolbox News

Psychtoolbox beta updated

kleinerm

Psychtoolbox 3.0.17 Beta update “Let them eat cake!” SP2 was released at 19th February 2021. As usual, the complete development history can be found in our GitHub repository. The release tag is “3.0.17.9”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.17.9

A minor PTB beta update, mostly featuring small bug fixes, doc updates and refinements.

General:

  • Add Denis Pelli’s MeasureLuminancePrecision.m as baseline to PsychAlpha/ . The script is already useful as it is, and received quite a bit of cleanup by myself wrt. Denis original. However, currently it is needlessly restricted to use of the ColorCal-II, and needs more refinement. We add it to the PsychAlpha alpha-quality folder for the time being, so it can have some use while it gets refined over time.

  • PsychtoolboxPostInstallRoutine(): Improve diagnostics slightly for textrenderer setup failures on MS-Windows or macOS.

  • Many minor fixes to demos and tests for Matlab R2020b compatibility. Various cleanups. Also many old and obsolete tests and demos deleted, which don’t have much use anymore in the year 2021. This cleanup and R2020b compatibiity work was sponsored by Mathworks.

macOS:

  • Fix MacModelName() for macOS Catalina. By Denis Pelli and Darshan Thapa.
  • DriftTexturePrecisionTest: Make compatible with macOS Retina displays.

Linux:

  • Minor help text updates in SetResolution() and Screen(‘Resolution’) wrt. multi-display setups.

Psychtoolbox beta updated

kleinerm

Psychtoolbox 3.0.17 Beta update “Let them eat cake!” SP1 was released at 8th February 2021. As usual, the complete development history can be found in our GitHub repository. The release tag is “3.0.17.8”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.17.8

A minor PTB beta update, mostly featuring small bug fixes, doc updates and refinements. And a new start screen.

General:

  • PsychRTBox: Robustness fix during box open. Sometimes the first query for the box id data delivers partial trash for unknown reasons. If that’s the case, requery.
  • BasicSoundInputDemo: Add missing setup for unified KbName. Otherwise the ESCAPE key is not recognized for mapping on Windows and we get error abort.
  • Update our Welcome splash to Celia’s latest and more eye-catching artwork.

Linux:

  • KbCheck: Add workaround for missing ESCape key on touchbar MacBook Pro’s without functioning touchbar. Map ~ key left to 1 key also to ESCAPE. Mostly for testing with Linux development kernels which do not yet have the Apple touchbar dkms drivers updated for use with them.
  • XOrgConfCreator: Use of intel-ddx implies DRI3/Present from now on. This is needed, because the intel-ddx does not choose the modern iris OpenGL driver on modern Intel chips, but still old-school i965 classic DRI driver, which is a mismatch to the desktop GUI and other clients choosing iris in such a scenario. Switching DRI3 on will make this a non-issue. Or in other words: No login failure when enabling color depth 30 bit / 10 bpc color precision mode on modern Intel graphics chips of Gen 8 and later on modern Linux distributions.
  • MultiTouchMinimalDemo / MultiTouchDemo: Add a small potential performance optimization.
  • “help RaspberryPiSetup”: Update to account for Raspbian bug fix.

Windows:

  • Screen/Windows: Add new visual diagnostic for DWM compositor interference. If Screen(‘Preference’, ‘VisualDebugLevel’, 6) is set and we run on Windows-8 or later, and a fullscreen window is opened - which shouldn’t be subject to DWM composition - then create the onscreen window with DWM redirection surface disabled. This will cause any DWM composited windows client area to not display at all, but instead just show transparent. This is a clear visual indicator that a window is subject to unwanted DWM composition, iow. if the DWM is the root cause for visual timing and timestamping problems.

Psychtoolbox beta updated

kleinerm

Psychtoolbox 3.0.17 Beta update “Let them eat cake!” was released at 23rd January 2021. As usual, the complete development history can be found in our GitHub repository. The release tag is “3.0.17.7”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.17.7

The most noteworthy improvement about the minor “Let them eat cake!” beta update is initial support for the RaspberryPi 4 and RaspberryPi 400, two quite nifty microcomputers.

A minor PTB beta update, mostly featuring christmas work:

All systems:

  • OffsetRect(): Allow single rect as both row and column vector, instead of only as row vector.
  • Some stuff by David Brainard in ComputePhotoPigmentBleaching(), described as “Implement bleaching kinects calculation”.

Linux:

  • Add support for the RaspberryPi 4 and 400 on 32-Bit Raspbian/RaspberryPi OS: Also some setup instructions and feature descriptions in the new help file “help RaspberryPiSetup”. The new Pi is in quite good shape, only sound output with PsychPortAudio over HDMI video output does not currently work, but that can be worked around, via the builtin soundchip and headphone jack, or - in the case of the RaspberryPi 400 without headphone jack - by plugging an external USB soundcard. The RPi 4 sports faster processor and graphics, more RAM, dual-display output, well working Wifi, and substantially improved graphics support, e.g., for high precision floating point textures and framebuffers, advanced shaders, and hardware accelerated video playback for some formats like H264.

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