Thanks for the help Brian. From an Internet search I find there is very little useful information about these options. I tried the -intra option and added -bv 50M so my libx264 filter lineup is:
-c:v libx264 -intra -vb 50M -crf 18 ouput.mov
MediaInfo says 14.7 Mb/s ! (this is with a lighter noise filter setting)
If it’s any consolation I can’t see degradation in the video. But, then it’s old cruddy video anyway. Is it worth the extra trouble getting the bitrate up?
EDIT: Shoot! I messed up the video bitrate configuration. No complaints on my command line though. I will try this yet another time…