CheckSbparam(3x)  MISC. REFERENCE MANUAL PAGES   CheckSbparam(3x)



NAME
     CheckSbparam,  GetTransFormatLength,  DoTransFormat,   Init-
     TransFormat, GetBaseLength - To handle sound data formats.

SYNTAX
     #include <io/sound.h>
     #include <soundlib.h>

     result = CheckSbparam( sbparam )
     int  result;
     struct sbparam  *sbparam;

     newLength = GetTransFormatLength( oldSB, newSB, oldLength )
     struct sbparam *oldSB, *newSB;
     int  newLength, oldLength;

     newLength = DoTransFormat( oldSB, newSB, oldSound, newSound, oldLength )
     struct sbparam *oldSB, *newSB;
     char oldSound[ oldLength ], newSound[ LONGENOUGH ];
     int  newLength, oldLength;

     InitTransFormat()

     baseLength = GetBaseLength( oldSB, newSB )
     int  baseLength;
     struct sbparam *oldSB, newSB;

DESCRIPTION
     CheckSbparam  checks  the  sound  data  format  being  used.
     sb_param  returns  0  if  the  sound  format is one of those
     described in sb(7) and returns  -1  otherwise.   The  fields
     sb_compress  and  sb_format are only checked when either the
     LOGPCM or ADPCM format has been selected.

     GetTransFormatLength gets the data  length  after  a  format
     conversion.   It  returns the new byte length for audio data
     of original byte length oldLength  in  the  original  format
     oldSB  after  that  data has been converted to audio data of
     the new format  newSB.  CheckSbparam  is  executed  on  both
     oldSBandnewSB  and  returns  -1  (error) if either are unde-
     fined.

     DoTransFormat performs the actual format conversion of sound
     data  files.   Sound  data  stored in oldSound of the length
     oldLength and of the format represented  by  oldSB  is  con-
     verted  to  the  format  represented  by newSB and stored in
     newSound. The length of the sound data is returned if it was
     converted successfully.

     InitTransFormat  initialized  filters  used  internally   by
     DoTransFormat.  InitTransFormat  must  be called once before
     calling DoTransFormat. This routine must also be called  any



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CheckSbparam(3x)  MISC. REFERENCE MANUAL PAGES   CheckSbparam(3x)



     time  a  data  conversion differing from the previous one is
     going to be made.

     GetBaseLength gets the value of the maximum length  of  data
     which  can  be passed to the format conversion routine.  Due
     to the fact that there are size restrictions on the internal
     filters  used,  there are also restrictions on the length of
     data that DoTransFormat can convert with  one  call.   Actu-
     ally,  depending  on the old and new data formats specified,
     only data of a certain length, or integral multiple of  that
     length,  can be converted at a time.  GetBaseLength gets the
     constant representing this length.  Use  the  format  before
     conversion  as  the  first  argument  and  the  format after
     conversion as the second.  The value of  this  constant  can
     get very large if ADPCM is specified as the format before or
     after conversion when making a frequency conversion.

FILES
     /usr/lib/libsound.a,                /usr/include/io/sound.h,
     /usr/include/soundlib.h

SEE ALSO
     sb(7), sbconv(1)
































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