# Psychtoolbox 3.0.19.15 release "Last free lunch" **URL:** \ **Category:** Announcements\ **Tags:** release\ **Created:** [November 3, 2024, 12:42am UTC](https://psychtoolbox.discourse.group/t/psychtoolbox-3-0-19-15-release-last-free-lunch/5535 "2024-11-03T00:42:52Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![mariokleiner](https://avatars.discourse-cdn.com/v4/letter/m/13edae/32.png) [@mariokleiner](https://psychtoolbox.discourse.group/u/mariokleiner)\ **Post date:** [November 3, 2024, 12:42am UTC](https://psychtoolbox.discourse.group/t/psychtoolbox-3-0-19-15-release-last-free-lunch/5535/1 "2024-11-03T00:42:52Z")
Psychtoolbox 3.0.19 update “Last free lunch” was released at 3rd November 2024. The complete development history can be found in our GitHub repository. The release tag is “3.0.19.15”, with the full tree and commit logs under the URL: [https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.19.15](https://github.com/Psychtoolbox-3/Psychtoolbox-3/tree/3.0.19.15) [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. ](https://www.mathworks.com/solutions/neuroscience.html) ### Compatibility changes wrt. Psychtoolbox 3.0.19.14: - None. ### Highlights: - None. Only bug fixes for various 3rd party components, and small improvements. ### All: - Change enumeration order of video capture devices. This should avoid selection of suboptimal capture devices by preferring more optimal ones, especially on modern Ubuntu 22.04-LTS and later Linux distributions, which often choose the new but immature pipewiresrc as video source plugin for a camera instead of the old and proven/mature more optimal v4l2src as video source. Specifically we hope to avoid VideoRecordingDemo.m problems like the ones encountered in the following thread: - PsychImaging: Fix HDR mode with types of PsychColorCorrection() that involve lookup tables and only use one color correction operation in total. E.g, standard LUT based correction, 3D LUT based correction or application of per-pixel gain matrices. See: - CI release scripts: Disable building of .mltbx files for releases for now. - Add Psychtoolbox/PsychBasic/PsychPlugins/ to the search path for dynamic shared libraries for all operating systems, so PTB specific plugin libraries can be found during mex file load time. ### Linux: - Psychtoolbox was built and lightly tested against Matlab R2024a and Octave 5.2 and later, and it was extensively tested against Matlab R2024b. - PsychImaging: Update ‘EnableNative16BitFramebuffer’ help text for year 2024. - Screen: Fix Vulkan display backend support with Mesa versions 23.3 and later and thereby for Ubuntu 24.04-LTS and later. The same problem that affected the Broadcom VideoCore 6 of the RaspberryPi 4 and later under Mesa 23.3 now affects at least Intel and AMD under Mesa 24.0 with Ubuntu 24.04.0-LTS. - PsychVulkan: Add workaround against an AMDVLK bug that causes crash if the used Vulkan display monitor has more than 64 video modes. A proper fix, especially for multi-display setups, can only be done in a future AMDVLK driver from AMD’s Vulkan team, but for single display stimulation this workaround should prevent crashes and problems, and on some multi-display setups things may still work with a sprinkle of dumb luck - no guarantees for multi-display though! Note that the AMDVLK driver is only used on AMD gpu’s if a color depth of more than standard 8 bpc (aka “deep color”) or HDR-10 display mode is requested. For other Vulkan use cases, the high quality Mesa radv Vulkan driver is used, which does not suffer such a problem. For context see: - XOrgConfCreator: Adapt to Ubuntu 24.04-LTS changes in /dev/dri/card enumeration. This broke hybrid graphics laptop detection, at least on three single gpu laptops with AMD gpu’s. It reported a dual-gpu config when there was not any. Since Ubuntu 24.04-LTS, or more likely with a recent Linux 6.8 kernel shipping in both Ubuntu 24.04-LTS and in Ubuntu 22.04.5-LTS with HWE stack, the first (and only) gpu on a single gpu machine now has a /dev/dri/card1 device file, instead of a /dev/dri/card0 device file, ie. device file indexing now starts at 1 instead of 0. On multi-gpu machines, the second gpu is now associated with /dev/dri/card2 and so on. This broke some hard-coded assumptions about 0-based device numbering. We now use a more robust detection logic for hybrid gpu detection. The fix was successfully tested on single-gpu AMD and Intel graphics machines, and on a dual-gpu Intel + AMD laptop for each gpu and in prime render offload mode. - Add braces for NetWM reporting to make compiler happier. It caused a weird problem in the Screen mex build for Matlab, in which the “PTB-INFO: …” lines about the used flip timestamping mechanism are not printed! No clue why, looks like some compiler bug, but adding the - technically not needed - braces fixes it. ### Windows: - Psychtoolbox was built and lightly tested against Matlab R2024a and Octave 7.3 and extensively tested against Matlab R2024b. - VideoRecordingDemo.m: Remove special case MS-Windows path. It does not seem to be as necessary anymore with the future default MediaFoundation path for capture and recording. Also added some cleanups and ability to specify video capture device as argument. ### macOS: - Psychtoolbox was built and tested against Matlab R2024a and against Octave 9.2 from HomeBrew. Enjoy!