Path: utzoo!utgpu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!usc!rpi!crdgw1!uunet!orca!baby!galt
From: me
Newsgroups: alt.hackers
Subject: Sound Blaster .VOC file format
Message-ID: <1991Mar7.002906.4258@dsd.es.com>
Date: 7 Mar 91 00:29:06 GMT
Sender: usenet@dsd.es.com
Followup-To: alt.hackers
Organization: ?
Lines: 54
Approved: by me
Nntp-Posting-Host: 130.187.85.165

Not too big of a deal, but using voc-hdr along with debug, I mapped
out the file format for Sound Blaster .VOC files...
-----------------------------------------------------------------
 

HEADER: (bytes 00-19)
=======
     byte #           Description
     ------           -----------
     00-12            Creative Voice File
     13-15            1A 1A 00  (eof to abort printing of file)
     16-17            Version number             (VOC-HDR puts 0A 01)
     18-19            2's Comp of Ver. # + 1234h (VOC-HDR puts 29 11)
 
DATA: (bytes 1A+)    A series of data blocks terminated by 00
=====
 
   Data Block:  TYPE(1-byte), SIZE(3-bytes), INFO(0+ bytes)
   -----------
 
      TYPE   Description   Size (3-byte int)   info
      ----   -----------   -----------------   ----
      01     Sound data    2+length of data    *
      02     ????
      03     Silence       3                   *
      04     Marker        2                   marker #
      05     ????
      06     Repeat        2                   # of repetitions
      07     End repeat    0
      08+    ????
 
*Sound info format:         *Silence info format:
 -----------------           --------------------
 00   Sample rate            00-01  Length of silence (weird encryption)
 01   Compression type       02     38
 02+  Data
 
 
Sample rate       -- SR byte = 256-(1000000/sample_rate)
Length of silence -- (# of .1 seconds encrypted)
Compression type  -- 8-bits    = 0
                     4-bits    = 1
                     2.5-bits  = 2
                     2-bits    = 3
                     Multi DAC = 3+(# of channels)
 
Silence encoding in VOXKIT finds quiet places in file, and creates a separate
block that is of type Silence.
-------------------------------------------------------------------
Next step is disassembling the ct-voice.drv driver and finding out how
to send data to the card.