Original commit message from CVS:
* gst/filter/gstlpwsinc.c: (gst_lpwsinc_mode_get_type),
(gst_lpwsinc_class_init), (process_32), (process_64),
(lpwsinc_build_kernel), (lpwsinc_set_property),
(lpwsinc_get_property):
* gst/filter/gstlpwsinc.h:
Add a highpass mode.