es -
number of elements in the array; 3) datatype – an enumeration of
possible types and 4) dataptr – a void data pointer to the same
data pointed to by the union pointer data. The data union field
enables access to the data using the bracket [] index notation of C
for the listed data types. The dataptr field enables bulk transfers
of data. The number of bytes can be determined by multiplying the
sizeof the datatype by the num_values field. The structure does
maintain dynamic memory, so use MtkCoreMetaD