Original commit message from CVS:
* ext/dv/gstdvdec.c: (gst_dvdec_class_init), (gst_dvdec_init),
(gst_dvdec_video_getcaps), (gst_dvdec_video_link),
(gst_dvdec_push), (gst_dvdec_loop), (gst_dvdec_change_state),
(gst_dvdec_set_property), (gst_dvdec_get_property):
* ext/dv/gstdvdec.h:
Implement drop_factor property to lower the framerate with
a factor.