How to get the embeded file's format?

I need to extract audio/video embeded in slide.
But [ IAudioFrame.getEmbeddedAudio().getContentType() ] can just tell me MIME type of the file.
How can I know file’s format exactly. Such as ‘.mp3’、’.wav’、’.au’…

@cmlinqb

The information about the file format is available in MIME Type. if you are having any trouble then please share the source presentation with us along with used sample code.