[MEncoder-users] mpeg conversions

[Rick C.]

Hello,

I've been doing some mpeg conversion tests coming from flash like this:

test.flv -ofps 30000/1001 -of mpeg -mpegopts format=mpeg2 -vf harddup -o test.mpg -oac lavc -ovc lavc -lavcopts threads=8:acodec=mp2:vcodec=mpeg2video:vbitrate=2500:keyint=15:vrc_buf_size=1835:vrc_maxrate=9800:vstrict=0

My question is I notice that if I leave out the -ofps 30000/1001 the video will not convert even if the original has a frame rate of 29.97.  I'm just curious when it comes to mpeg must I specify a frame rate every time?  I notice normally converting to other formats such as .mp4 it's not necessary it will just keep the existing frame rate...

If I can add a related question...if I'm coming from a frame rate of let's say 29.97 and I want to go down to let's say 25 is there a way to do this without the "jumpy" appearance?  Or is that the nature of lowering the frame rate?

Thanks!

rc