[theora] mixed interlaced content and ffmpeg2theora

[Michael A. Peters]

dv file from minidv camera - interlaced.

small dv created by imported jpeg images - not interlaced.

seems that when I use ffmpeg2theora with deinterlace switch and reduce 
size, it works. But when the only reduction I am doing is to width 
(720x480 -> 640x480) the encoder ignores the naturally interlaced bit 
and uses the last de-interlaced frame.

Since the small bit made from jpegs is a dv file of its own before 
merging with the minidv, is there some way I can interlace it so it 
plays nice? I looked at ffmpeg switches to see if I could interlace it 
with that before adding it to the minidv source but didn't see an 
interlace option.