afGetAESChannelData(3dm)                              afGetAESChannelData(3dm)


NAME
     afGetAESChannelData, afSetAESChannelData - get/set AES channel status
     information in an AFfilehandle structure for an audio track

SYNOPSIS
     #include <dmedia/audiofile.h>

     int afGetAESChannelData(AFfilehandle file, int track,
                              unsigned char buf[24])

     void afSetAESChannelData(AFfilehandle file, int track,
                              unsigned char buf[24])

PARAMETER
     file    expects an AFfilehandle structure, previously created by a call
             to afOpenFile(3dm).

     track   expects an integer which identifies the audio track in the file.
             Since all currently supported file formats allow at most one
             audio track per file, the constant value AF_DEFAULT_TRACK should
             always be used for this argument for now.

     buf     is a data buffer used to pass the 24 bytes of AES channel status
             data to afSetAESChannelData(), or to obtain the 24 bytes of AES
             channel status data from afGetAESChannelData().

RETURN VALUE
     afGetAESChannelData() returns 0 if there is no AES channel status
     information associated with the given track, 1 if there is AES data, and
     -1 in the event of an error.

DESCRIPTION
     afSetAESChannelData() writes the specified AES channel status data bytes
     into the appropriate header location of file.  If no header space has
     been reserved in the header by afInitAESChannelData(3dm), the routine
     will ignore the data and return.

     afGetAESChannelData() copies the channel status data for track into buf.
     If no AES channel status data is found, it returns 0.

CAVEATS
     These functions will always manipulate data that is to be interpreted as
     AES channel status data, but there is never any guarantee that such data
     will be present in a given input file or not, or will be allowed in a
     given output file or not (unless the file format of the file being read
     or written requires that AES data is always present).  Even in the
     formats AIFF and AIFF-C, the presence of AES channel status data is
     optional.


SEE ALSO
     afOpenFile(3dm), afReadFrames(3dm), afInitChannels(3dm), aifc(4)


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