MP3Frame :: size - Frame size
(copied from http://id3.org/id3v2.4.0-structure)
The size descriptor contains the size of the data in the final frame, after encryption, compression and unsynchronisation. The size is excluding the frame header ('total frame size' - 10 bytes).
When the frame is invalid, the function throws an exception.
Return value: Size ( int32 )
Size of the instance or property area. For string objects, the size is usually measured in units.