DTparseframe(3dm)

NAME
     DTparseframe - parse a frame of DAT audio data

SYNOPSIS
     #include <sys/types.h>
     #include <dmedia/dataudio.h>

     void DTparseframe(DTPARSER* dtp, DTFRAME* dtfp)

PARAMETERS
     dtp    A pointer to the target DTPARSER

     dtfp   A pointer to the frame of DAT audio data to be parsed.

DESCRIPTION
     DTparseframe parses a frame of digital audio data read from a DAT.  It
     determines which subcodes are present in the data. If those subcodes have
     changed since the last frame, then DTparseframe executes a callback of
     the appropriate type [see DTaddcallback] passing to it the subcode data
     found in the frame.

     Callbacks are only executed when the subcodes change because subcodes
     tend to come and go and calling whenever a particular subcode is seen
     would be unpredictable.  Also several of the subcodes never change on the
     tape but may be repeated thousands of times.  Executing a callback every
     time the same subcode is seen would be very inefficient.  For unchanging
     subcodes, the callback is executed the first time the subcode is seen.  A
     program that wishes to see the data every frame is free to look directly
     into the DTFRAME structure.

     If a dt_audio callback is set, DTparseframe executes that callback every
     frame after byte-swapping and, if the tape indicates it is necessary,
     de-emphasizing the data.

SEE ALSO
     DTintro(3dm), DTaddcallback(3dm), DTcreateparser(3dm),
     DTdeleteparser(3dm), DTremovecallback(3dm), DTresetparser(3dm),
     datframe(4)

AUTHOR
     Mark Callow