Yves and Guenter, thanks for your replies, and Yves, I'm sorry to make you answer that question yet again.
It looks like I need to simply find, for now some QT files with jpeg codec...
In the meantime, I've dropped my search for pdp_ffmpeg~ and switched to trying pdp_theonice~
However, I run into the same problem: pd can't create it, along with several other objects, including pdp_charcoal, pdp_i (but pdp_o is okay) and pdp_icedthe~
Any ideas? Am I isiing something really fundamental here? I must confess I'm getting into an area I don't really understand...
PD 0.38.0 (Guenter's Debian package) pd-pdp-caedes 1:0.12.4-2 pd-pidip-caedes 0.12.17-1 libtheora 0.0.0.alpha4-1
cheers dafydd