I’m setting up a Discourse instance, and would like to integrate content from short online classes (videos of ~ 10 min) and webinars. What would be a good video platform to integrate with Discourse? I would like users to not have the feeling of “changing platforms” (even with SSO, etc.), I don’t know if that would be possible.
I also want to integrate other media, like blog and others, but this type of content I understand that it is easier to mimic within Discourse, perhaps with categories.
Discourse beautifully and seamlessly embeds video content from Vimeo and YouTube.
You may need to define or explain your required level of integration further? 
Sorry, I should have been more specific. I want to build a “system” that includes:
For video lessons, I need to control participants (paid and free), set up classes, etc. Registration can be done on an external platform, but once the user is “inside” the “system”, I would not like him to have the impression that he is accessing different platforms for each of the above contents.
There is no way to integrate Discourse into another platform in this way – dropping it into an iFrame will break functionality and cause performance issues. I’m interested in why you would want the video lessons to be on another platform though. Why not just publish the videos within topics as Richie suggests?
Just to clarify: Discourse can be the “main” platform (in fact, it probably will, the community will be the central component).
It’s not clear to me how I could control classrooms, enrollments, payments, etc. in an automated way.
Take a look at discourse-subscriptions.
I completely missed this plugin 
I will try to build a MVP.
Thanks a lot!