php readFile()和移动safari

I am working on app that among other things is using the AVAssetExporter to combine video and audio file into new video. Exported video: plays fine in a web view inside the application. when it is saved using UIIMagePickerController it plays fine from the Camera app. when I am uploading video to a server it plays fine in a desktop version of Safari and Firefox.

But when I am trying to access the video from the mobile safari, I am getting the Movie Couldn't be Played Tip from the debug console.

AVAssetExportSession *exporter =[[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetPassthrough];
        exporter.outputFileType=AVFileTypeQuickTimeMovie;

My question is what kind of export settings should I use in order to create a video that will work on mobile devices? thank you

Edit 1. It appears that it might be connected with the way how how my server side is set up. I found out the following: http://mobiforge.com/developing/story/content-delivery-mobile-devices

I will keep this post updated.

Best bet: mp4 with h.264 and aac

It appears that it might be connected with the way how how my server side is set up. I found out the following: http://mobiforge.com/developing/story/content-delivery-mobile-devices