ns_GetSegmentSourceInfo

 ns_GetSegmentSourceInfo   Retrieves information about the sources that
    generated the segment data

    Usage:
        [ns_RESULT, nsSegmentSourceInfo] = 
                ns_GetSegmentSourceInfo(hFile, EntityID, SourceID)

    Description:
        Retrieves information about the source entity, SourceID, for the
        Segment Entity identified by EntityID, from the file referenced
        by the handle hFile. The information is written to the
        nsSegmentSourceInfo.

    Parameters:
        hFile           Handle/Indentification number to an open file.
        EntityID        Identification number of the Segment Entity.
        SourceID        Identification number of the Segment Entity source.

    Return Values:
        nsSegmentSourceInfo     ns_SEGSOURCEINFO structure that receives
                                information about the source.
        ns_RESULT   This function returns ns_OK if the file is successfully
                    opened. Otherwise one of the following error codes is 
                    generated:

                        ns_BADFILE      Invalid file handle passed to 
                                        function
                        ns_BADENTITY    Invalid or inappropriate entity 
                                        identifier specified
                        ns_BADSOURCE    Invalid source identifier specified
                        ns_FILEERROR    File access or read error

    Remarks:
        The value of SourceID is an integer index value ranging from
        0 to SourceCount-1 (which is returned by the function
        ns_GetSegmentInfo).

    Copyright (C) 2003 Neuroshare Project
    Author: Almut Branner
    Last modification: 6/20/2003