I am creating DVDs for my child's elementary school. I shot ceremony in the gym/auditorm with teachers speaking at podium in front of a black stage curtain. No stage lighting. On the final DVD the black curtain is a mess of dancing macro blocks. Shot with GH3 in MOV format, 72Mbps. I'm editing in iMovie. Footage looks fine in iMovie. I have exported as 1080p from iMovie. After creating a DVD with iDVD, the black curtain is basically a big macro block. I know I'm using consumer tools but I can't understand why these black curtains are getting so crushed. The rest of the frame looks fine--teacher at podium, students, etc. Is there anything I can do to get a better encode? Would compressor do a better job?