I wrote:

Can someone point me to some info on this? I've read everything I can find, including all of the technical documentation. I even think I understand the entire filter interface and most of what's going on in vf_tinterlace.c, but there's a disconnect somewhere.

[..snip..] 4. changed all height's to height/2 in calls to memcpy_pic. I get core dumps if I don't, and it makes sense to me to make this change.

Nevermind. I was being bitten by the "special case" of dstStride == srcStride in which the whole image is copied in a single memcpy. I need the stride-by-stride copy of, e.g., my_memcpy_pic, that several folks have implemented in their various filters. Problem solved for the moment. Sorry for the interruption. At some point I hope to have a patch ready for review by you folks. WB __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com