How to feed the "file source" block?

Hi everybody! I am in the process of collecting some signals. Do I want
FM discriminator output or digital IQ? I don’t know what kind of file to
feed to the file source block: .wav or .mp3 or what?


You should provide file with sample values inside, and it depends on
kind of signal have you recorded, complex, real, etc… Since you are
collecting some signals, i suppose you are using file sink block in
to store data to file, so all you have to do is to provide that file to
file source.
I am not giving answers so often, so please excuse me if i was wrong.