mp4 vs m3u8 format

I am trying to play a video in iPhone, which开发者_StackOverflow中文版 has m3u8 format. The video's link is parsed from an XML (so i cannot change it). I'm trying to play it with MoviePlayerController (set it on fullscreen, controlStyle is fullscreen too, set the presentModalViewController to the MoviePlayerController). After pressing the play button, the movie has only sound for a few seconds, no video screen, and the app crashes.

In this XML I have a different videolink, which contains mp4 format. Playing the video in the same mode (with MoviePlayerController and the settings...), it works fine. So: do you have any ideas what the problem is? If there is any encoding problems of m3u8? If it can be changed and how?

Thank you :)

Look the AVPlayerDemoPlaybackViewController class from this very useful open source control released by Peter Steinberger
https://github.com/steipete/PSPushPopPressView
Thanks again Peter!