There was some delay to play a video in my iPhone app (Integrate with iOS SDK 2.1.0 - JWPlayer) , when compared with Android app (Integrate with Android SDK 2.1.1 - JWPlayer) . Is this because of SDK? Also i want to know, " How much time it will take to start playing a video in MP4 file format and a VAST tag?".
My name is Daniel and I am an iOS SDK Support Engineer. I would be happy to assist you. Please note that the latest iOS SDK is 2.4.4.
Can you please implement your video file in our open source project and email the project to support+sdk@jwplayer.com?:
https://github.com/jwplayer/jwplayer-sdk-ios-demo
To answer your second question, the time to play an MP4 as well as a VAST ad should be very quick (fractions of a second). You can implement the onFirstFrame delegate to measure the exact time to first frame:
https://developer.jwplayer.com/sdk/ios/reference/Protocols/JWPlayerDelegate.html#//api/name/onFirstFrame: