mvTrackDataParams(3dm)                                  mvTrackDataParams(3dm)


NAME
     mvTrackDataParams: mvGetTrackNumDataParams, mvAddTrackDataParams,
     mvSetTrackDataParams, mvGetTrackDataParams - manipulate data in track


SYNOPSIS
     #include <dmedia/moviefile.h>


     int mvGetTrackNumDataParams( MVid track );

     int mvAddTrackDataParams( MVid track, DMparams *params );

     DMstatus mvSetTrackDataParams( MVid track, DMparams *params );

     DMstatus mvGetTrackDataParams( MVid track, int dmParamsIndex,
                                    DMparams *params );


DESCRIPTION
     Each chunk of data in the file is described by a set of DMparams.  The
     following functions allow applications to access these params.  To
     retrieve the index of the DMparams that describes a certain chunk of
     data, use mvGetTrackDataIndexAtTime(3dm).

     mvGetTrackNumDataParams returns the number of data params in the list of
     the track.

     mvAddTrackDataParams adds a data description parameter to the list of
     parameters in a track.  The function returns an index into the list at
     which point the new params were inserted.  The applicable parameters in
     DMparams passed into this function are copied into private movie library
     structure.  Users are responsible for creating and destroying the
     DMparams pointed to by params.  This function fails if params is not
     valid.  The parameters usually have the same requirements as those
     required by mvAddTrack(3dm).

     mvGetTrackDataParams copies all the parameters from the data params
     indexed by index into the dmparams passed into the function in params.
     The user is responsible for creating and destroying this DMparams.  This
     function fails if the index is out of range.

     mvSetTrackDataParams replaces parameters in DMparams pointed to by the
     params corresponding to index by those pointed to by params.  The user,
     again, is responsible for creating and destroying the params passed into
     this function.  This function fails if the index is out of range.


NOTES
     Note that most file formats other than QuickTime only support one data
     parameter per track. For formats other than QuickTime, therefore, changes
     made with these functions may not be written to disk.


SEE ALSO
     mvIntro(3dm), mvTrackData(3dm), mvReadTrackData(3dm),
     mvInsertTrackData(3dm).


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