jp2_colour::get_vendor_data

If get_space returns JP2_vendor_SPACE, this function returns a pointer to the internal buffer used to represent the vendor colour space (everything after the 16-byte UUID in the colr box's METHDATA field). Otherwise, the function returns a NULL pointer.

The returned block of memory, if any, belongs to the internal object; no attempt should be made to delete it or to use it beyond the lifetime of the object which originally supplied this interface.

num_bytes [int *]