How to MPEG-DASH video streaming in iOS?

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.

You can setup proxy server on a device and then create a parser that will be translating mpd files into m3u8 and serve m3u8 for AVPlayer. For ios proxy GCD should do the trick: GCDWebServer

Try providing both HLS and DASH containers and let media queries choose the appropriate one.