
          Ŀ
           The Microsoft Multimedia WAV Sound File Format 
          

                 Written for the PC-GPE by Mark Feldman
            e-mail address : u914097@student.canberra.edu.au
                             myndale@cairo.anu.edu.au

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                   THIS FILE MAY NOT BE DISTRIBUTED     
              SEPARATE TO THE ENTIRE PC-GPE COLLECTION. 
             



 Disclaimer 


I assume no responsibility whatsoever for any effect that this file, the
information contained therein or the use thereof has on you, your sanity,
computer, spouse, children, pets or anything else related to you or your
existance. No warranty is provided nor implied with this information.


 The RIFF File Format 


WAV files use the RIFF file structure. The RIFF format was designed
for multi-media purposes. A RIFF files consists of a number of "chunks":

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   Byte              Length                                               
   Offset   Name   (in bytes)    Description                              
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   00h      rID        4h        Contains the characters "RIFF"           
   04h      rLen       4h        The length of the data in the next chunk 
   08h      rData     rLen       The data chunk                           
  



 The WAVE Form Definition 


The rData chunk in a WAV file is split up into several further chunks:

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  rData                                                                   
  Byte              Length                                                
  Offset   Name   (in bytes)    Description                               
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  00h      wID        4h        Contains the characters "WAVE"            
  04h      Format    14h        Contains data which specifies the format  
           Chunk                  of the Data in the Data Chunk           
  18h      WAVE Data  ?         Contains the WAV audio data               
           Chunk                                                          
 




 The Format Chunk 


The Format Chunk is split up into these fields:

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 Format                                                                  
 Chunk                  Length                                           
 Offset  Name         (in bytes)   Description                           
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 00h     fId               4       Contains the characters "fmt"         
 04h     fLen              4       Length of data in the format chunk    
 08h     wFormatTag        2       *                                     
 0Ah     nChannels         2       Number of channels, 1=mono, 2=stereo  
 0Ch     nSamplesPerSec    2       Playback frequency                    
 0Eh     nAvgBytesPerSec   2       **                                    
 10h     nBlockAlign       2       ***                                   
 12h     FormatSpecific    2       Format specific data area             


* The wFormatTag specifies the wave format, eg 1 = Pulse Code Modulation
  (or in plain english, regular 8 bit sampled uncompressed sound)

** Indicates the average number of bytes a second the data should be
   transferred at = nChannels * nSamplesPerSec * (nBitsPerSample / 8)

*** Indicates the block alignment of the data in the data chunk. Software
    needs to process a multiplt of nBlockAlign at a time.
    nBlockAlign = nChannels * (nBitsPerSample / 8)



 The Data Chunk 


The Data Chunk is split up into these fields:

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  Data                                                                   
 Chunk                  Length                                           
 Offset  Name         (in bytes)   Description                           
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 00h     dId              4        Contains the characters "data"        
 02h     dLen             4        Length of data in the dData field     
 00h     dData            dLen     The actual waveform data              


In mono 8-bit files each byte represents one sample. In stereo 8-bit files
two bytes are stored for each sample, the first byte is the left channel
value, the next is the right channel value.
