Thanks Dave,
That's not my voice....

The M4A file is an other format.
I know that BASS library but i like to try it myself and learn something on the way.
It's just for fun to use the mp3 codec but i need to feed it with the proper info of the mp3 files.
Layer-1 is the only one which i don't have and i need one to examine it so i can play all types of MP3 files in my program.
Tried several converters but non of them create a layer-1 file.