[FFmpeg-user] Re-encode mpeg2 for same quality

[petesea at frontier.com]

Any chance I could get a little explanation why setting -minrate less 
than -maxrate gives a warning saying it "isn't recommended!"?

I realize -minrate is mostly used for setting CBR, but I can't find 
anything that really explains why it shouldn't be used for other than 
that...ie for setting an actual range... as in MIN - MAX.

In my case it SEEMS to do what I want which is increase the bitrate. 
Which I assume means it's retaining more of the original source, since the 
resulting bitrate is much closer to the original source. Is it not really 
doing that?

Here's an example command:

   $ ffmpeg -i video.vob -codec:v mpeg2video -b:v 6000k -bufsize 6000k -minrate 4000k -maxrate 9800k -codec:a copy -copyts -f vob video-MINMAX.vob

The source file has a bitrate of 4685k.  Without the -minrate option, the 
bitrate goes down to 1852K.  WITH the -minrate option it's back up to 
4567k.