mvGetTrackDataFieldInfo(3dm)mvGetTrackDataFieldInfo(3dm)NAME
mvGetTrackDataFieldInfo, mvSetTrackDataFieldInfo, mvTrackDataHasFieldInfo
- get track data info
SYNOPSIS
#include <dmedia/moviefile.h>
DMstatus mvGetTrackDataFieldInfo( MVid track, int index,
size_t *firstField,
off64_t *gap,
size_t *secondField );
DMstatus mvSetTrackDataFieldInfo( MVid track, int index,
size_t firstField,
off64_t gap,
size_t secondField );
DMboolean mvTrackDataHasFieldInfo( MVid track, int index );
DESCRIPTION
The data to describe a single image in an image track may be made up of
two fields. In a QuickTime file, an auxillary table can be stored in the
meta data to describe the sizes and relative positions of these fields.
These functions allow users to get at field information. Currently, this
feature is only supported on QuickTime files.
mvTrackDataHasFieldInfo
This function must be called to determine whether a chunk of data has
field information. The function returns DM_TRUE if field information is
available and DM_FALSE otherwise. An error will occur if the track is
invalid (error code: MV_BAD_ID) or if the index is out of range (error
code: MV_PARAM_OUT_OF_RANGE). Legal indices can be found by using the
function mvGetTrackNumDataIndex.
mvGetTrackDataFieldInfo
This function fetches the field information for a particular data chunk
in a track. If the function succeeds:
firstField will contain the size of the first field
gap will contain the size of the gap between the first and the second
field as written in the file
secondField will contain the size of the second field
The function can fail under the following conditions:
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mvGetTrackDataFieldInfo(3dm)mvGetTrackDataFieldInfo(3dm)
1. if track is invalid. (error code: MV_BAD_ID) 2. if index is out of
range. (error code: MV_PARAM_OUT_OF_RANGE) 3. if the data is not of image
type or is not interlaced. (error code: MV_INVALID_DATA_TYPE) 4. if the
information is not available. (error code: MV_INFO_NOT_AVAILABLE)
mvSetTrackDataFieldInfo
This function sets the field information for a particular data chunk in a
track. The parameters are interpreted as follows:
firstField contains the size of the first field
gap contains the size of the gap between the first and the second field
as written in the file
secondField contains the size of the second field
The function can fail under the following conditions:
1. if track is invalid. (error code: MV_BAD_ID) 2. if index is out of
range. (error code: MV_PARAM_OUT_OF_RANGE) 3. if the data is not of image
type or is not interlaced. (error code: MV_INVALID_DATA_TYPE)
Once this information is set it is available for all movie file formats
at run time. Since the information is only saved out to QuickTime files
you must ensure that the movie is a QuickTime movie if you wish to
retrieve the information after the file has been closed.
SEE ALSOmvReadTrackDataFields(3dm), mvInsertTrackDataFields(3dm).
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