its known issue, that not all codecs are available in emulator, same goes with devices as well. Thus you can only use audio formats which are supported by the platform you are using.
I have moved this to the Symbian C++ forum - as a rule it is best to post your questions in the most specific forum. "Feedback and Services" is not a good forum for talking about a specific tool.
In future, can you please also use lower case for your headings. All upper caps in messaging can look a little "aggressive", which I am sure was not your intent.