How to MPEG-DASH video streaming in iOS?

I am trying to write a JavaScript-based implementation of MPEG-DASH for video streaming. I have referenced the following documents:

• dash.js - https://github.com/Dash-Industry-Forum/dash.js/wiki
• Google Shaka Player - https://github.com/google/shaka-player

These libraries are using MSE (Media Source Extensions).

My understanding

MPEG-DASH is an international standard for streaming video, but it is currently not natively supported in iOS devices. In other browsers and devices, it requires a JavaScript library or a video player that supports MPEG-DASH (eg: Dash.Js, Shaka player).

And another streaming technology is HLS. It is an adaptive streaming communications protocol created by Apple. The Safari browser can play HLS streams within a web page, iPhone, and iPod touch devices.

Here, we can see that MPEG-DASH (because of MSE) is currently not natively supported in iOS devices.

Now, my doubts:

1. How can we stream MPEG-DASH videos in iOS without MSE?
2. How Facebook and other streaming media services play their videos? is it with HLS only ?

Any suggestion/explanations would be more than helpful!

1. You can’t.

2. Yes they use HLS. iOS 10 and above support fmp4 in HLS. so the only difference between dash and hls is the manifest.