PsychStartup: Environment variable GSTREAMER_1_0_ROOT_X86_64 is undefined.
PsychStartup: Either GStreamer-1.4 is not installed at all, or if it is installed then something
PsychStartup: is botched. Trying various common locations for the GStreamer runtime to keep going.
PsychStartup: Path to GStreamer runtime is undefined! This probably means that
PsychStartup: the 64-Bit GStreamer 1.x runtime from www.gstreamer.net is not installed.
PsychStartup: The Psychtoolbox Screen() multimedia functions and the new 'DrawText'
PsychStartup: high quality text renderer will fail to work until you fix
PsychStartup: this! Read 'help GStreamer' for instructions.
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GStreamer is installed as per the instructions (i.e. all offered packages) in C:\gstreamer. I've tried reinstalling both PTB and GStreamer and the problem persists. Any help/suggestions would be greatly appreciated. I'm running Matlab 2012a on Windows 10 Pro (64).
It expects C:\gstreamer\1.0\ to exist and then sets the sdk root to C:\gstreamer\1.0\x86_64\
So apparently that folder doesn't exist, because something went wrong on your side. Did you install Gstreamer with admin privileges? Might be a good idea to avoid Windows virtualizing the real folders on the C drive away as part of the "new" Windows Vista security concept. Otherwise your installation may only appear to be correct for the user that installed GStreamer. Just a hunch, i thankfully usually don't have to use Windows, and if i must do, only under an admin account.
Wrt. the missing environment variable, have you tried turning it off and on again?
Ok, so that’s a couple years too late, but I had the same issue and maybe a clear answer can help someone or me in a year when I bump into the same issue).
What helped for me was making sure that the latest version of Gstreamer is installed BEFORE Psychtoolbox. If you already have a version of Psychtoolbox installed, backup it and install it from scratch. Updating the toolbox didn’t help in my case.
And second, make sure that the ‘\Psychtoolbox\PsychBasic\MatlabWindowsFilesR2007a’ folder (containing the Screen MEX file is above the ‘’\Psychtoolbox\PsychBasic’ folder in the MATLAB search paths. It prevented later MEX file problems for Screen.
That’s wrong advice if a missing or wrong GStreamer installation was the only problem. A simple restart of Matlab/Octave, or maybe a logout + login on some systems, is sufficient. A cd(PsychtoolboxRoot); SetupPsychtoolbox; if you want to be extra sure.
That happens automatically at each download or update as part of DownloadPsychtoolbox, UpdatePsychtoolbox, or SetupPsychtoolbox unless something would be wrong with your Matlab path permissions.