This method is called when the buffer is being saved to a file. The return value should be TRUE if there were no errors. Override this method for your own use, but always call the inherited method so that it can write its own extra headers. The default method does nothing.
To write a header, call
wxMediaBuffer::BeginWriteHeaderFooterToFile (section 
),
passing in the address of a long integer. Then write the header data
and end by calling
wxMediaBuffer::EndWriteHeaderFooterToFile (section ),
, passing back the long integer that was set by BeginWriteHeaderFooterToFile. Unless you follow this procedure
correctly, you will not be able to get the header data back at
read-time (and the file will be corrupted).