[MEncoder-users] Using vqscale with vrc_maxrate under lavc gets sloooooooow

[David Smith]

I am trying to find the perfect command line that will let me encode both
low action and high action scenes with an equal combination of acceptable
quality and file size.  Btw, I only care about converting to Flash so I can
only use *lavc.*

Some of my low action vids actually have bitrates around 300-400kbps.  These
would be like speakers at a podium where not much is happening, but the
producer doesn't want to see blocky solids in the background or the
speaker's mouth all blurred.

An example of high action would be Apple's high-def quicktime movie of
creatures moving around under water (
http://www.apple.com/quicktime/guide/hd/shark.html).

Basically I want to encode both kind of files to a relative quality without
having to worry about bitrates, however, I naturally want a decent file size
on the high action, high-def vids.

So I am working with vqscale and maxrate to come up with a combination where
the relative quality is high, but the high-def vid won't exceed a certain
bitrate threshold and generate a massively large file.

I am using the params below, but my encoder bogs down to the point where it
is only encoding about 1 frame PER SECOND and I'm not exactly sure why.  I
have a state-of-the-art desktop.

mencoder shark_720p.mov -o shark_exp9j.flv -oac mp3lame -lameopts
vol=5:abr:br=56 -srate 22050 -ovc lavc -lavcopts
vcodec=flv:vqscale=4:vrc_maxrate=3000:vrc_buf_size=1835:mbd=1:mv0:trell:v4mv:cbp:last_pred=3
-mc 1 -of lavf -vf harddup

I have read that vqscale will end up wasting lots of bits on complex scenes
and producing a bitstream that requires way too much cpu power to decode and
if I don't have proper constraints and a long complex scene eats all the
bits, then lavc makes subsequent simple scenes look like crap trying to
recover from its excessive bit usage.

I thougth I was adding a constraint by enforcing maxrate, but perhaps it's
still too much?

Anyone have ideas how I can generate a good quality output and file size
regardless if the input video is low or high quality (or low or high
action), and without being forced to use a constant bitrate?  Thanks.