mvTrackData(3dm)					      mvTrackData(3dm)

NAME    [Toc]    [Back]

     mvTrackData: mvGetTrackNumDataIndex mvGetTrackDataInfo
     mvGetTrackDataOffset mvGetTrackDataIndexAtTime - retrieve information
     about track data

SYNOPSIS    [Toc]    [Back]

     #include <dmedia/moviefile.h>


     int mvGetTrackNumDataIndex( MVid track );

     DMstatus mvGetTrackDataIndexAtTime( MVid track,
	      MVtime time, MVtimescale timescale,
	      int *index, MVframe *frameOffset );

     DMstatus mvGetTrackDataInfo( MVid track,
	       int index, size_t *returnSize, int *paramsId,
	       MVdatatype *dataType, MVframe *frames );

     DMstatus mvGetTrackDataOffset( MVid track,
	       int index, off64_t *fileOffset );

DESCRIPTION    [Toc]    [Back]

     Each instance in time correspond to some chunk of data in the file,
     unless it belongs to an empty segment.  Functions in this page provide
     information about these chunks of data referenced by a track.

     mvGetNumDataIndex

     This function returns the number of data chunks referenced	by a track.

     mvGetTrackDataIndexAtTime

     track is the id of	the track.

     time is the time instance the user	wishes to query.

     timescale is the time scale for time.

     index contains the	returned index.	If index==-1, then the time which you
     are querying about	contains an empty edit (which was created with
     mvInsertTrackGapAtTime or mvInsertMovieGapAtTime).	This is	how one	can
     easily test for track gaps.

     frameOffset contains the frame offset from	the beginning of the chunk to
     which the time instance corresponds. If the returned index	is -1, this
     value is meaningless.

     mvGetTrackDataInfo




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mvTrackData(3dm)					      mvTrackData(3dm)



     track is the id of	the track.

     index is the index	of the data chunk the user wishes to query.

     returnSize	contains the size of the data chunk returned by	the movie
     library.

     paramsId contains the index to the	set of DMparams	that describes this
     data chunk.  See also mvTrackDataParams(3dm).

     dataType contains the datatype of the data	chunk.	Currently, only
     MV_FRAMETYPE_MASK is supported, of	which only MV_FRAMETYPE_DELTA and
     MV_FRAMETYPE_KEY are supported.

     frames contains the number	of frames in the data chunk index.

     mvGetTrackDataOffset

     Takes an index and	fills in the fileOffset	with the offset	in bytes of
     the start of the chunk referenced by index.

     track is the id of	the track.

     index is the index	of the data chunk the user wishes to query.

     fileOffset	is the location	where the data chunk resides on	the storage
     device.

SEE ALSO    [Toc]    [Back]

     mvIntro(3dm), mvReadTrackData(3dm), mvInsertTrackData(3dm),
     mvInsertTrackDataAtOffset(3dm), mvInsertFramesAtTime(3dm),
     mvTrackDataParams(3dm).


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