Can I copy a part of an audio file stored in Ipod Library and save it with different name?

Hi I have went through a lot of searching and have deduced that

1) I can query for a specific audio file from Ipod Library and can play it using MPMusicPlayerController Library. But the problem is I cannot copy a part of this song and save it with diffrent name.

2) Using AVAudioPlayer I can modify or copy a part of an audio file but the problem is the audio file must be present in Application's resource folder. It doesnot allow me to choose a file from Ipod Library.

My requirement is to choose a file from Ipod Library and save a p开发者_开发技巧art of the same audio file with diffrent name.Please suggest how this can be achieved. There is one application which is doing similar task, but I cannot figure out how it is doing it.

http://itunes.apple.com/us/app/custom-ringtone-creator/id394095644?mt=8

Any suggestions would be highly appreciated. Thanks in advance

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See here:

http://www.iphonedevsdk.com/forum/iphone-sdk-development/62807-export-audio-m4a-alac.html