Videos Delivery service for Learning magement System(LMS)

I am working on WordPress based LMS. For courses videos, I need video delivery Service that full fill following services

1. Course Videos uploaded by instructors directly upload to service provider server and streamed from service provider server
2. Course Enrolled students not able to download the videos, only watch them online.

I google for this, then two option AMAZON S3 and cloudfront came across me. But I am little bit confuse what is right choice for my requirements ? Any other videos delivery service that include free tier also welcome.