RTSPAVPlayer

Draft of playing RTSP utilize native iOS player (AVPlayer).

How to build

To build the app:

1. Run script /thirdparty/ffmpeg/general/build-ffmpeg.sh (prefered version of ffmpeg is 4.1)
2. Run xcode project (tested with wowza test rtsp url: https://www.wowza.com/html/mobile.html)