[MEncoder-users] rc buffer underflows

[Nico Sabbi]

n0dalus wrote:

>Hi,
>
>I am converting some files to mpeg2 raw video (PAL DVD) and I am
>getting a lot of messages like this:
>[mpeg2video @ 0x857b330]rc buffer underflow
>[mpeg2video @ 0x857b330]rc buffer underflowin 449mb  A-V:0.000 [2904:0]
>
>The command I am using is:
>mencoder -of rawvideo -vf scale=720:576,harddup -nosound -ovc lavc
>-lavcopts vcodec=mpeg2video:keyint=25:vbitrate=4305043:aspect=4/3:vrc_maxrate=9800:vrc_buf_size=1835:vpass=2
>-mpegopts format=dvd -speed 40000/40000 -ofps 25 -passlogfile
>video.pass -o video.m2v video.ogm
>
>  
>

although it's not related to your problem, -of rawvideo and -mpegopts 
combined together
are 100% nonsense: when you mux to rawvideo you don't use the mpeg muxer.
Additionally. -speed 40000/40000 doesn't have any logic

>Later when I try to mplex these, I get a lot of errors (I am unsure if
>the problems are related, but I suspect that the mencoder buffer
>underflows are responsible).
>
>I would be grateful to know what causes these buffer underflows and
>what (if anything) I can do to fix them.
>
>n0dalus.
>
>  
>

try to add a sensible vrc_minrate with lmin=1:vqmin=1:mbqmin=1