Video Output Over USB-C Hubs With DisplayLink Drivers
mark last edited by mark
In a recent forum post, a user pointed out that Isadora 3.1.1 and Isadora 3.0.8f12 were not compatible with USB-C Hubs that rely on DisplayLink drivers. I wanted to address this briefly.
SHORT VERSION: Yes, it is true that many hubs that rely on DisplayLink drivers are incompatible with Isadora, though there is perhaps one exception. (See "EXCEPTION" below.)
LONG VERSION: It is clear that most USB-C Hubs that rely on DisplayLink drivers don't work with Isadora because the drivers do not allow you to create a valid OpenGL context, something that's required for high speed rendering. But, I wanted to find out more. So I went to the (excellent!) local Mac shop to purchase one of these hubs so I could try it. While the headline of the DisplayLink web page leads off with the headline"Truly Universal", a tech at the shop said that these devices caused so many problems for so many customers with so many apps, that they simply stopped selling them. They now actively tell their customers not to use devices that rely on DisplayLink at all.
EXCEPTION: @liminal_andy shared a post about a specific USB Hub from a company called Plugable that apparently does work very well with Isadora. Perhaps there are others. But I can say with some confidence that is Andy says it works well, then you can have some confidence it does in fact work well.
So we're sharing their recommendation: we currently do not recommend these devices for use with Isadora. If you do find some that work well, then please reply here and share your experience with the community.
P.S. I want find a way to investigate this when I can make time for it. Even though the DisplayLink system will be inefficient compared to a for-real OpenGL enabled output, I want to see if there is at least a workaround that allows 1) Isadora to work with these devices, and 2) for us to warn the users the device will be low performance.