Need a quick working ffmpeg project

I want a simple non gui c++ project which uses [login to view URL] (etc) to encode mp3 files to other files i specify like wav, wma, mp4. I have tried to do this myself but it fails when using mp3 files with missing header errors or invalid data (I have tried different ways). I am using qnx platform armv7 cpu to do this and can send you the latest build of [login to view URL], [login to view URL], etc which has lame and x264 compiled with it. Compiled myself. Some things to note which might help the developer.. when I call av_find_stream_info with mp3 files with the latest ffmpeg build it hangs but if i pass a wma file it wont hang. I have tried many different mp3 files also. I have tried to do this using fread also instead of av_read_frame but then i get missing header errors. I have been trying to do this myself as i say for over week just for learning purposes so any fellow developers like to show me how it's done at a reasonable price then please do. Regards