Need a little help with multiple inputs

[Eric Geoffroy]

Hoi,

GNU Parallel is so great I can hardly contain my excitement of finding it.
Thanks to excellent documentation, examples, and videos, my peanut brain has 
been able to construct an almost working command. 

I have a dir of video files. The goal is to copy the videos from dir A, rename, 
and copy to dir B overwriting only if source is newer than destination. 

I found a few different ways to do this in parallel. I also experimented with 
cp, ditto, and rsync.

I'm using perl for the rename and multiple inputs for parallel. This line works-

echo /Users/ugeofer/Desktop/tutorial/09_09-0321962041.mp4 | perl -pe 'print; 
s/9780321962041/9780133432336/' | parallel -N2 ditto {1} {2}

Here's where I need help.  I haven't been able to figure out how to specify the 
new directory. I've tried-
~/Desktop/{2} and all sorts of variations. 

I'm so close. Any help appreciated. 

- Eric