[FFmpeg-user] Converting a 23.98p source to 29.97i ProRes w/interlaced 3:2 pulldown?

[Mel Matsuoka]

I'm trying to convert 23.98p ProRes QuickTime (.mov) files to interlaced 29.97 ProRes files, and I'd like to do the frame-rate conversion to 29.97i by using a 3:2 pulldown cadence (upper-field first). 

I can't seem to figure out how to do this in FFmpeg 2.8 on Mac OS X 10.10.5. I am able to convert the 23.98 source to 29.97, and the encoded file *is* technically interlaced, but the actual frame-rate conversion to 29.97 seems to be happening using progressive pulldown (i.e. repeated full frames), even though the file itself is flagged as having UFF interlacing. 

Because the 29.97 files are intended for broadcast playback, I need to be able to convert the 23.98 master QuickTime files to broadcast-spec'ed, interlaced 29.97 ProRes files with true interlaced 3:2 pulldown, so that they look smooth when played on-air. 

Here's the command line that I've come up with so far.

ffmpeg -ss 7.0 -t 30.0 -i SOURCFILE.mov -timecode 01:00:00:00 -acodec pcm_s16le -vcodec prores_ks -vprofile hq -flags +ildct -r 29.97 -movflags +write_colr -color_primaries bt709 -color_trc bt709 -colorspace bt709 OUTFILE.mov

This command line skips the 7 second slate/leader at the head of the spot, and encodes exactly 30 seconds of the file after that, while re-striping the output file with a new timecode track starting at 1 hour. I'm also using the Kostya ProRes encoder, as I have been led to believe that the other ProRes encoders in FFmpeg don't support interlaced output?  

Everything seems to encode as I'd like it to, with the exception of the lack of interlaced pulldown. I've spent all day scouring the web, as well as a dump of "ffmpeg -h full", but I can't seem to figure out how to get this to work.  Any help would be most appreciated.