Format of WAV header
 --------------------

 4 bytes 'RIFF'         ; RIFF tag
 4 bytes <length>       ; length of remaining stuff
 4 bytes 'WAVE'         ; WAVE tag
 4 bytes 'fmt '         ; 'fmt' chunk     
 4 bytes  <length>      ; 10h - length of chunk
 2 bytes  01 	        ; format
 2 bytes  01 	        ; channels (1=mono, 2=stereo)
 4 bytes  xxxx	        ; samples per second
 4 bytes  xxxx	        ; average samples per second
 2 bytes  01 	        ; block alignment
 2 bytes  08 	        ; bits per sample
 4 bytes 'data'         ; 'data' chunk
 4 bytes <length>       ; Length of data chunk (actual sample data)
         <sample data>  ; Here starts the real thing :-)
         ...
         ...


For PCM data, the block alignment is the number of bytes used by a 
single sample, including data for both channels if the data is stereo. 
For example, the block alignment for 16-bit stereo PCM is 4 bytes (2 
channels, 2 bytes per sample).


Note: the sample data must end on an even byte boundary.
      All numeric data fields are in the Intel format
      of low-high byte ordering.
.