Psychtoolbox 3.0.19 update “Sommerloch” was released at 11th August 2024. As usual, the complete development history can be found in our GitHub repository. The release tag is “3.0.19.14”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.19.14

Compatibility changes wrt. Psychtoolbox 3.0.19.13:

• None expected.

Highlights:

• None.

All:

• Screen('DrawDots'): Only apply a margin to non-square dot types. Only round dots get trimmed in the fragment shader, and so dot_type=4 was left with too much padding from the vertex shader. Bug fix contributed by Alex Forrence @aforren1

• Python extensions built from this release onwards should also work with NumPy 2.x in addition to NumPy 1.x. Changes contributed by Eric Larson.

Linux:

• Psychtoolbox was built and tested against Matlab R2024a.

• Undo Screen('OpenMovie') compatibility fix for Ubuntu 24.04-LTS, of using pipewiresink as audio sink. While this does fix the pulseaudio bugs of delayed playback (see Psychtoolbox 3.0.19.12), the pipewiresink plugin itself, as shipping in Ubuntu 24.04-LTS / GStreamer 1.24, has its own bugs, which are worse and impact more frequent use cases, e.g., seeking, change of playback speed, reverse playback, and instabilities or hangs at end of playback for some common movies. Iow. use of pipewiresink causes regressions.

  See forum bug report here:

  https://psychtoolbox.discourse.group/t/10-second-delay-with-with-gst-state-change-async/3924

  GStreamer folks know about the problem but there ain’t a solution yet.

  As of this release, the pipewiresink can still be used as an active opt-in, accepting other potential types of audio playback problems, and if opted in, should fix the following issue on Ubuntu 24.04-LTS and later, and other distributions that use Pipewire as desktop sound server and have an outdated buggy Pulseaudio 16 installation, instead of the more recent Pulseaudio 17.

  See the following issue for this bug, which is luckily not encountered often:

  https://github.com/Psychtoolbox-3/Psychtoolbox-3/issues/814

  On unfixed affected systems (mostly Ubuntu 22.04-LTS), if there is a notable time delay between Screen('OpenMovie') and start of video+audio playback via Screen('PlayMovie'), then the movie playback will freeze after displaying the 1st video frame for the duration of that delay between OpenMovie and PlayMovie, then continue. Problem didn’t exist in earler Linux distributions like Ubuntu 20.04-LTS and is fixed by this bug fix for later distros like Ubuntu 24.04-LTS from April 2024.

  The use of pipewiresink can be enforced as workaround by specifying the following string as ‘movieoptions’ parameter in Screen('Openmovie', ...); ‘AudioSink=pipewiresink’.

• RaspberryPi now also allows GetSecs clock selection, like the Intel variants do since a few releases.

Windows:

• Psychtoolbox was built and lightly tested against Matlab R2024a and Octave 7.3.

• GetGitPath(): Fix path to git on MS-Windows. Bug fix contributed by Alex Forrence @aforren1

macOS:

• Psychtoolbox was built and tested against Matlab R2024a and against Octave 9.2 from HomeBrew.

• SetupPsychtoolbox(): Try to fix it properly for macOS with xattr calls. Skip xattr calls for .mltbx installed files via Matlab Add-On explorer, as those already have their quarantine flags removed.

  For other (zip file) install locations, handle blanks/spaces in the installation path.

  Also some output text cleanups and fixes. Tested with .mltbx and zip file path install on path with spaces etc. Lets hope this goes better.

Enjoy!