MonoTouch: Record audio in compressed format like .m4a

I tired this example: http://wiki.monotouch.net/HowTo/Sound/How_to_record_sound_using_the_iPhone_microphone

But when I change the AudioFileType, from a compressed type (MP3) the file size is the same as WAV开发者_开发知识库E.

Am I doing something wrong?

Thanks.

This is the list of encoders exposed by iOS:

http://developer.apple.com/library/ios/#qa/qa2008/qa1615.html

And it does not support MP3 encoding

This was previously discussed here:

iPhone - AVAudioRecorder - how can I record to an mp3?

The only alternative is for you to include your own MP3 encoder and negotiate directly with the MP3 patent holder the terms.