Comment 28 for bug 1969512

@seb128 yes, the following command line plays (for at least 20 seconds -- I didn't watch the whole thing) happily under totem:

MESA_GL_VERSION_OVERRIDE=3.3 totem big_buck_bunny_720p_surround.mp4

So the issue is simply that the pi's GL driver only goes up to 2.1, and/or that GTK doesn't accept GL<3.0 (my vague understanding of the graphics situation on the pi is that the GLES driver has (had?) rather better support than GL, but that Vulkan was the real focus of development efforts -- https://www.raspberrypi.com/news/vulkan-update-version-1-1-conformance-for-raspberry-pi-4/ has some more info on that).