[MPlayer-users] vbitrate option doesn't affect filesize

[Jack]

Jaap Struyk wrote:

>Hello,
>
>Trying to create a kvcd mpeg1 stream with mencoder the vbitrate option
>doesn't affect filesize.
>Probebly because I made an error with the command but I cant find the
>clue.
>Can somebody please point me in the right direction?
>I use something like:
>
>mencoder And_Now_For_Something_Completely_Different.avi -noskip -ovc
>lavc -oac lavc -lavcopts
>acodec=mp2:abitrate=112:vcodec=mpeg1video:vrc_maxrate=5000:vbitrate=800:lmax=10:vrc_eq=1:keyint=24:vmax_b_frames=2:mbd=2:vstrict=-1:vrc_buf_size=327:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,12,14,18,27,29,34,37,38,22,26,27,31,36,37,38,40,26,27,29,36,39,38,40,48,27,29,34,37,38,40,48,58,29,34,37,38,40,48,58,69,34,37,38,40,48,58,69,79:inter_matrix=16,18,20,22,24,26,28,30,18,20,22,24,26,28,30,32,20,22,24,26,28,30,32,34,22,24,26,30,32,32,34,36,24,26,28,32,34,34,36,38,26,28,30,32,34,36,38,40,28,30,32,34,36,38,42,42,30,32,34,36,38,40,42,44:aspect=16/9 -af volume=+5dB -srate 44100 -channels 2 -vf scale=352:220,expand=352:240,scale=352:240,eq2=1.0:1.0:0.0:1.0 -of mpeg -fps 23.976 -ofps 23.976 -o kvcd.mpg
>  
>
Usually when someone reports this problem, it's because mencoder is 
already using the lowest quantizer for most of the movie.  It has 
quality as high as it can go, and it has no need to use any more bits.  
For something with that low of a resolution, it's pretty likely that 
this is the case.  Especially if it's already been encoded and 
re-encoded a few times before.

If setting a lower bitrate shrinks the file, or if setting vqmin=1 and 
lmin=1 increases the bitrate, this is the case.  Note, however, that 
vqmin=1 and lmin=1 will give only marginal quality improvements over the 
default of 2, and will consume a lot more bits -- there really isn't any 
point to using it.

-lt