afGetTrackIDs(3dm)                                          afGetTrackIDs(3dm)


NAME
     afGetTrackIDs - get the list of track descriptor id's for the given
     AFfilehandle

SYNOPSIS
     #include <dmedia/audiofile.h>

     int afGetTrackIDs(AFfilehandle file, int trackids[])

PARAMETER
     file       expects an AFfilehandle structure, created when an audio file
                was opened by a call to afOpenFile().

     trackids   expects an array of integer locations used to return a list of
                (unique) positive track id's which can be used to reference
                the audio tracks in a file.

                If trackids is a null pointer, afGetTrackIDs()  will simply
                return the number of tracks in the file.  This value can be
                used to allocate a trackids array, which can in turn be passed
                back to afGetTrackIDs().

RETURN VALUE
     afGetTrackIDs() returns a nonnegative integer count of the number of
     audio tracks in the file, or -1 in case of error.

DESCRIPTION
     You can call afGetTrackIDs()) with a null trackids pointer to obtain the
     number of audio tracks contained in file.

     You can use this count to allocate a trackids[] buffer, which you pass
     back to afGetTrackIDs to obtain a list of unique track id's. You can then
     use these id's to reference the various tracks in the file.

     For the current release of the Audio File Library, this routine is a
     placeholder, since all currently supported file formats always contain
     one track which should be referenced using the constant ID
     AF_DEFAULT_TRACK.

CAVEATS
     This function may return more than one track.  Future releases of the
     Audio File Library may support formats which contain multiple tracks.  An
     application might want to reject such a file, or perhaps use the first
     track.  The library does define the correct behavior.

SEE ALSO
     afOpenFile(3dm), afReadFrames(3dm), afWriteFrames(3dm),
     afInitTrackIDs(3dm)


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