Original commit message from CVS:
* gst/videobox/gstvideobox.c: (gst_video_box_fill_get_type),
(gst_video_box_class_init), (gst_video_box_set_property),
(gst_video_box_i420), (gst_video_box_ayuv), (gst_video_box_chain):
Use pad_alloc where possible.