after 3 days loosing all days and nights of good sleep, I finaly did!
Finaly, I edited SoundRecorder, the standard recorder app of xperia x10 mini, xperia mini, and some others devices, to record audio in AAC encoder, with 16 bit encoding and 22khz of sample rate!
The difficult thing for me was to learn java and object orientation to do this (believe, I'm dumb with these 2 things )
Well, here I go.
First, I watched this video to learned how to get started:
Then, I downloaded the source code from this site:
and using androids developer's home page and oracle's man page, I could correct some erros, and recompile the APK.
Finaly, here is the project if you would like to improve the program , which I will do in the future to add some functions like choose sample rate, container, and codecs, and in the folder bin you find the APP
To install, you can use eclipse, connecting your phone to your computer through usb and hit run android app or use this program:
APK Edit v0.4, allows you to edit your apk file
That is it!
Thanks and, please, comment!