[MPlayer-users] [BUG] mencoder cannot encode to the required bitrate

[Peter Gavin]

On 9/2/06, 陆然 <hephooey at gmail.com> wrote:
> I've found a solution, -vf harddup will do the trick.

Using -vf harddup will just waste space in this case.  mencoder
sometimes duplicates frames to maintain sync.  To save space, this
duplicated frame is really just a pointer (in the AVI file, not the
actual video stream) to the previous frame, not a complete copy.
(Well, from what I understand, this is how it works.  I can think of
other ways it might work, however.)  So your actual bitrate will end
up being lower as a result.  Using -vf harddup forces mencoder to
write out an actual copy of those frames (which is just wasted space
in most cases).  You don't get any better quality, but the resulting
bitrate will match what you expect.  See the mencoder man page (and
search for harddup).

Pete