Happy New Year!

Psychtoolbox 3.0.20.1 “Appletizer SP1” was released at 12th January 2025.

The complete development history can be found in our GitHub repository. The release tag is “3.0.20.1”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.20.1

Compatibility changes wrt. Psychtoolbox 3.0.20.0:

• None

Highlights:

• None. This is a minor macOS Apple Silicon maintenance release.

macOS:

• Psychtoolbox was built and tested against native Matlab R2024b and against native Octave 9.3 from HomeBrew, on macOS 13.7.1 Ventura for Intel Macs, and on macOS 14.5 Sonoma for Apple Silicon Macs.

• Try to execute same code path on Apple Silicon macOS, regardless if running under native Matlab/Octave for Apple Silicon ARM, or running under Intel Matlab/Octave via Rosetta2 emulation. Our license management aggregate stats tell us that a non-trivial fraction of users still use Matlab for Intel Macs via Rosetta2 emulation on Apple Silicon, instead of the recommended native Matlab/Octave for Apple Silicon. This would cause PTB to misbehave, as it would think it runs on an Intel Mac and acts accordingly, instead of adapting to the special snowflake that is macOS on Apple Silicon. This will especially cause trouble with visual stimulation timing and some visual stimulus presentation. Note that this fix tries to fix this, but Psychtoolbox is not and will not be tested for proper compatibility and quality when running under Matlab/Octave for Intel via Rosetta2 on Apple Silicon! Switching to native Matlab/Octave for Apple Silicon / ARM is strongly recommended.

• Audio demos and tests: Request standard latency instead of larger latency on Apple Silicon. The lose latency requirement was only meant to accomodate RaspberryPi’s, not Apple Silicon.

Enjoy!

Psychtoolbox 3.0.20 “Appletizer” was released at 13th December 2024, at least in some time zone. Hopefully Friday 13th will bring us luck instead of horror.

The complete development history can be found in our GitHub repository. The release tag is “3.0.20.0”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.20.0

This is the first release with beta quality macOS Apple Silicon Mac support for native use on Apple Macintosh computers with 64-Bit ARM Apple proprietary M1, M2, M3, … SoC’s.

We thank the labs of Keith Schneider at the University of Delaware and of Bas Rokers at NYU Abu Dhabi for substantial sponsorship to push Apple Silicon support over the finish line.

Effective immediately, the Psychtoolbox 3.0.19 series has now reached end of life. No improvements, bug fixes or user support will be provided for Psychtoolbox 3.0.19 or earlier versions of Psychtoolbox.

Compatibility changes wrt. Psychtoolbox 3.0.19.16:

• Psychtoolbox 3.0.20 and later on Apple macOS and Microsoft Windows will require purchase of a paid software license key, once the initial time-limited free trial period after first installation and use has expired. Psychtoolbox will not work after the end of the trial period without such a paid license key. The Psychtoolbox variants for Linux on Intel processors and 32-Bit RaspberryPi will remain free to use for the time being.

  The free time-limited trial period will last until the launch of our new online shop, ie. until you will be able to buy software license keys. The estimated date of launch, and end of the free trial, will be likely around early to mid January 2025.

  Follow the news on http://psychtoolbox.org and on our Discourse user forum or our social media feeds @psychtoolbox on X / Twitter, https://neuromatch.social/@psychtoolbox on Mastodon, or on BlueSky <@psychtoolbox.bsky.social> for announcements of the launch of the software license key sale early in the year 2025, or go to https://psychtoolbox.net to find out how to buy a key, once sales has started.

Highlights:

• Initial “Beta” Apple Silicon support for running Psychtoolbox on macOS for Apple Silicon Macs. Psychtoolbox can now be used with native Octave and Matlab for Apple Silicon ARM Macs, ie. machines with Apple M1, M2, M3, M4, … SoC’s. Most basic functionality should work reasonably well, and substantially better than when using older Psychtoolbox versions via Matlab for IntelMacs, which had various severe limitations which would make them painful to use and deeply hazardous for any real data collection! This versions Apple Silicon support was tested by myself on a Apple MacBookPro early 2023 with 16 inch Liquid Retina XDR display and Apple M2 Pro SoC under macOS 14.5 Sonoma with 64-Bit native Octave 9.2 from HomeBrew, and with Matlab R2024a and with Matlab R2024b. It was also more lightly tested by others on a similar 16 inch MacBookPro late 2023 with M3 Pro SoC under the macOS 15.2 Sequoia beta under Matlab R2024b, and a MacBookAir 2020 with M1 SoC, and a Mac Studio 2023 M2 Ultra and MacBookAir M3 13 inch early 2024, the latter two with macOS 15.2 beta and Matlab R2024b. Thanks to our volunteer testers.

  While surely some bugs or limitations still exist, this should be a first good release for basic use and evaluation.

  Known limitations are lack of frame-sequential stereo support in stereo modes 1 and 11, Screen Async flips, ie. subfunctions ‘AsyncFlipBegin’, ‘AsyncFlipEnd’ and ‘AsyncFlipCheckEnd’ are unsupported. Certain glitches in frame presentation timing are still observed under certain conditions at least on macOS 14, e.g., stalls / short freezes after the stimulus image was static for a while, e.g, observable with MouseTraceDemo if not moving the mouse for a while. These may also trigger printing of some warning messages into the Matlab or Octave Window about “…Failed to retrieve … stimulus onset timestamp! Timed out.”. It is not yet clear if these issues are still present on macOS 15 Sequoia as well, testing to be done. These remaining timing glitches are almost certainly due to Apple macOS operating system bugs, which will either need proper fixing by Apple, or need invention of new creative workarounds on our side, if that is needed and possible.

  Apples “ProMotion” display mode on some builtin Retina displays, e.g., of the MacBookPro models, and variable refresh rate modes in general, are not supported and will cause more erratic behaviour. Make sure to switch to a fixed refresh rate mode in display settings instead on such machines.

  Movie playback, movie writing and video capture works well with GStreamer 1.24.10, but due to what seem to be shortcomings or bugs of current GStreamer releases, video recording on Apple Silicon only works for video, not when also trying to record audio - otherwise hangs will occur. On Intel Macs, video recording does not work at all with GStreamer 1.24.10, but does for both video and audio with GStreamer 1.22, however with the downside that playback of some movies fails. So both GStreamer 1.22 and 1.24 have some limitations, pick the variant with limitations you can better live with, until GStreamer is properly fixed in some future GStreamer version.

  You should probably not yet use this release for real data collection if highest reliability of visual stimulus presentation timing is required. Use for less demanding scenarios may be fine, but tread carefully with this early release!

All:

• Screen: Fix PsychNormalizeTextureOrientation() for multi-window use. Use of multiple onscreen windows could cause the wrong OpenGL context of the wrong onscreen window to be in use during operation. Fix this. Cfe. https://psychtoolbox.discourse.group/t/unknown-problem-playing-movies-with-gstreamer-on-ubuntu-linux/4876/8

• Screen: Various improvements to movie playback. E.g., improve reliability of playback with pixelFormat 6 and 8.

• Screen: Reduce chattiness of some status/debug output in general. Generally refine status output a bit.

• AlphaRotateDemo.m: Small fixups for weirdly sized displays and formatting fixes. Especially useful for the Retina displays of 16 inch Apple Silicon MacBookPro, with a horizontal resolution that has an odd pixel count instead of an even count.

• PsychPython/audio.py: Fix ‘AttributeError’ raised when creating a stream fails. Contributed by GitHub user @mdcutone.

• PsychColorimetric/LMSToMacBoyn(): “Add an example and save the correct version”, some poorly documented fixes or improvements by the Brainard lab with commit messages that are mostly void of meaningful information, so I don’t know what they did.

• Various other smaller refinements, bug fixes and documentation updates.

Linux:

• Psychtoolbox was built and tested against Matlab R2024b and Octave 5.2 and later.

• PsychVulkan: Only use workaround against an AMDVLK bug, which causes a crash if a used display monitor has more than 64 video modes, on AMDVLK driver versions before v-2024.Q4.2, as the bug has been fixed by AMD in the upstream driver version v-2024.Q4.2, released by AMD early December 2024.

Windows:

• Psychtoolbox was built and tested against Matlab R2024b and Octave 7.3.

• Screen: Drop GStreamer DirectShow video capture. Prioritize Mediafoundation. DirectShow video capture is unmaintained and strongly discouraged by GStreamer folks since the year 2022, and indeed testing shows it is quite broken now. WDM-KS kernel streaming is also deprecated since the year 2022. MediaFoundation capture is the only recommended way forward. Limited testing on Windows 10 22H2 also shows it to be the most capable and stable right now (tested GStreamer 1.22).

  Drop support for DirectShow dshowvideosrc completely, and prefer Mediafoundation mfvideosrc over the deprecated Kernel Streaming ksvideosrc.

• PsychVulkan/Windows: Disable fullscreen exclusive mode on shoddy AMD Vulkan drivers again. This still does not work reliably and often leads to black screens instead of stimulus display. The error pattern was unpredictable, with fullscreen exclusive mode sometimes working throughout long sessions, then suddenly failing, with no way to fix it (even a reboot doesn’t help), then on another day suddenly working again for a streak of runs. Upside is a working display, but downside is impaired visual stimulus presentation timing reliability.

macOS:

• Psychtoolbox was built and tested against native Matlab R2024b and against native Octave 9.2 from HomeBrew, on macOS 13.7.1 Ventura for Intel Macs, and on macOS 14.5 Sonoma for Apple Silicon Macs.

• Initial support for running Psychtoolbox on macOS for Apple Silicon Macs with ARM native Matlab and Octave. See Highlights section above for more details.

• Bump the minimum required macOS version to macOS 10.13 “High Sierra”. Effective this means that macOS 10.13 for IntelMacs, and macOS 11 “Big Sur” for Apple Silicon Macs are required to run Psychtoolbox 3.0.20.

  Of course this new minimum is a bit redundant, because all macOS versions older than macOS 13 are completely unsupported by Apple since October 2024, so running anything older is at least a high computer security risk, and has lots of unfixed remaining bugs and is therefore not a good idea. Additionally macOS 13 is needed at a minimum on Apple Silicon Macs to allow proper operation of visual stimulators from VPixx and Cambridge Research Systems.

• Fix video recording on macOS. Works fully with video + audio on macOS for Intel Macs with GStreamer 1.22. Works with video only, no audio, on macOS for Apple Silicon Macs.

• Implement initial pixelFormat 11 movie playback support on macOS for playback of Deep color, Wide color gamut (WCG), and High Dynamic Range (HDR) movies. This provides 10 bpc deep color, WCG and HDR, but at a lower performance than on other operating systems, as Apples prehistoric OpenGL 2.1 implementation forces us to use a less efficient decoding shader, and hardware accelerated video decoding can not be used as of GStreamer 1.24.10, as it would reduce color precision to only 8 bpc which is utterly insufficient for WCG and HDR playback, causing significant banding and HDR artefacts.

• Make pixelFormat 6 playback work without crashing.

• Screen: Make Intel iGPU pageflip checking on recent macOS for Intel graphics chips more robust. This may improve robustness of correctness checks on Intel integrated graphics on Intel Macs with PsychtoolboxKernelDriver installed. Problem seen and fixed on Intel Kabylake Gen 9.5 graphics of MacBookPro 2017.

• Fix some crashes on Octave for macOS when using Psychtoolbox after issuing a “clear all”, or “clear mex”, or “clear Screen”, or “clear PsychVulkanCore” command.

Enjoy!

Psychtoolbox 3.0.19.16 “Last free dessert” was released at 20th November 2024. The complete development history can be found in our GitHub repository. The release tag is “3.0.19.16”, with the full tree and commit logs under the URL:

https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.19.16

This Psychtoolbox release was sponsored by Mathworks under the year 2024 contract for establishing Matlab R2024b compatibility on Ubuntu 24.04 Linux and Windows 10.

Highlights:

• None. This is a release with small fixes and tweaks, based on compatibility testing of Psychtoolbox with Ubuntu Linux 24.04.1-LTS and MS Windows-10 22H2 with Matlab R2024b under the Mathworks 2024 contract which requires at least one Psychtoolbox release that is compatible with R2024b under Linux and Windows.

  As such, no compatibility testing was performed wrt. macOS, apart from quick spot testing with R2024b, as testing on macOS was not part of the paid contract, and the contract pays way too little to cover any non-mandatory work.

  The total work time spent on R2024b testing and refinement was 42 hours.

  No compatibility issues were found with R2024b, compared to R2024a, iow. no regressions. All improvements in this release are for fixing / working around Microsoft Windows bugs or flaws, or AMD and NVidia graphics driver bugs on Windows. And some small tweaks and enhancements.

All:

• RenderDemo: Add missing BackupCluts to not annoy the user. Restore the lut’s at the end of the demo, so display doesn’t look “milky” and dull.

• FlipTimingWithRTBoxPhotoDiodeTest: Let audio card select its preferred sample rate. Some Some recent sound chips don’t like our hard-coded 44100 Hz, so let them choose their preferred rate.

• PlayMoviesDemo: Cleanup web movies offering a bit.

• PsychImaging: Some doc update wrt. Intel 10 bpc support on Ubuntu 22.04+.

Linux:

• Psychtoolbox was extensively tested against Matlab R2024b, under Ubuntu 24.04.1-LTS Linux with AMD Polaris and Intel Kabylake graphics, also in dual-gpu configurations on a dual-gpu hybrid graphics Laptop.

Windows:

• Psychtoolbox was extensively tested against Matlab R2024b, and lightly tested against Octave 7.3, both under MS-Windows 10 R22H2 with primarily AMD graphics, and spot checked with NVidia graphics.

• MultiWindowLockStepTest: Fix failure in default dual-window 10/20 seconds async flip case on MS-Windows 10, due to interaction with an OpenGL quirk.

• DrawManuallyAntiAliasedTextDemo: Add workaround for AMD OpenGL graphics driver bug on Windows-10. Ditto for TextToStuffColorMismatchTest.m.

Enjoy!