Regular Expression To get the string of a Youtube Video

I want to download a youtube video from a link say:

http://www.youtube.com/watch?v=j5开发者_Python百科-yKhDd64s

How to get the mp4 version of this flash video using regular expression, with Objective-c? Please point me to some sample code.

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You actually can't do it with any Regular expression since youtube videos are in FLV format and are being played via a custom flash player when watched over a browser. while using the iPhone / Ipad the iOS has a alternative player which is build into the OS and plays the video for you. that is why you can play youtube videos using this technique.

I would suggest opening youtube videos as it is intended in the SDK documentations check out this link: http://iphoneincubator.com/blog/audio-video/how-to-play-youtube-videos-within-an-application