To put it simply: users will not require an ActiveX component to view streaming media – a media player embedded into the page will work just fine.
I think the real question is in the capabilities of the server pushing the camera. Can it stream the video in the first place? At any rate, this is what you should be looking at, not some platform-specific, browser specific (Windows, IE) solution.
If the camera has the capability to output individual images (say, 2 image every second) it would be elementary to write a script to reload the image twice every second. Depending upon the application, this might be a more stable as well as easier to set up way to go – and the image could just be a simple jpeg and require nothing fancy at all.