Environment variable GSTREAMER undefined in windows 10

I’m searching help for this problem:
On windows 10 (64bit), installed gstreamer-1.0-msvc-x86_64-1.18.1 with adminstrator rights and psycotoolbox 3. At matlab start user without administrator rights receive the error message below.
The error is arise by /PsychInitialize/PsychStartup.m
PCs are used by students who cannot obtain administrative rights during their psychtoolbox class.


Error message*
PsychStartup: Environment variable GSTREAMER_1_0_ROOT_MSVC_X86_64 is undefined.
PsychStartup: Either GStreamer-1.18 MSVC or a later version is not installed at all, or if it is installed, then
PsychStartup: something is botched. Trying various common locations for the GStreamer runtime to keep going.

PsychStartup: Adding path of installed GStreamer runtime to library path. [C:\gstreamer\1.0\msvc_x86_64\bin]

That environment variable is a user variable, meaning its only set for the user you installed gstreamer under. You need to get it set for the student/non-admin accounts as well, by someone who has those rights.

That said, it seems that gstreamer is found anyway? Is this an error or a warning that you get?

I’m not a psycotoolbox user so I haven’t a deep understandig of it, but I install it for student and professors.

Simple instruction as Screen(‘Preference’, ‘SkipSyncTests’, 1); win=Screen(0,‘OpenWindow’,[],[0 0 640 480]); DrawFormattedText… works.

My doubt was that psychtoolbox was not fully functional or some function was compromised due to the message. I do not understand if gstreamer is a core component of psychtoolbox or if it is used only by some functions and in this case with which function I can test that gstreamer works.

I have tried to run screen function in a psychtoolbox installation without gstreamer. It doesn’t work.
So I think gstreamer is necessary for the function screen.
The message “PsychStartup: Environment variable GS…is undefined” is only a warning and gstreamer is found anyway.
It is correct?

Perfect, all is working. Indeed, GStreamer is required. You should be set then!

To be extra sure, you could run DrawFormattedTextDemo and GarboriumDemo, and any other demos using functionality your users may need to use. But sounds like you’re all set.

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Screen wouldn’t load at all (“Invalid mex file” error) if GStreamer wouldn’t be working, so your stuff works. The warning message is a warning, but the workaround worked to work around the problem on your setup. If GStreamer is installed in the default location of C:\gstreamer or other common drives like D: E: … the workaround should work.

Some older PTB versions didn’t require GStreamer on Windows+Matlab, but functionality would be limited wrt. text drawing and anything video capture / multi-media.


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Hi, I have a problems about the PTB 3.10.0 should use GSTREAMER 1.0 or 0.10? Thanks!

I don’t understand what v3.10.0 is supposed to be, but here’s this: