[MPlayer-users] Mencoder: Changing frame rate (RealMedia to vcd)

[Bill Moseley]

Stabbing around in the dark, I used this to convert a Real Media file
into a vcd.  It works, but I'm not so sure I'm doing things the right
way.  Here's all the commands in case I'm doing something incorrectly:


   mencoder  -ovc lavc -lavcopts vcodec=mpeg1video \
             -oac lavc -lavcopts acodec=mp2 \
             input.rm

   transcode -i test.avi -Z fast --export_prof vcd-ntsc -o temp
   mplex -f 1 -o vcd.mpg temp.m1v temp.mpa
   vcdimager vcd.mpg
   cdrdao write --device /dev/cdr video.cue


I don't see any advantage of using svcd since my source is only
320x240.


A few questions:

1) is is possible to avoid the transcode step and have mencoder
generate the mpeg directly?  I assume I'd need to scale from the
Realmedia image size to vcd images size (320x240 -> 352x240).
Something like this?

   -vf scale -zoom -xy 352

(I don't understand the -zoom, though)

But how do I get the mpeg container instead of the avi which I can use
for vcdimager?


2) I have one .rm file that's encoded at 15fps.  -ovc lavc says it
can't handle that fps:

   [mpeg1video @ 0x403b9008]MPEG1/2 doesnt support 15/1 fps

I can use -fps 30, but then the video is, obviously, fast.


I really could use a primer on fps and bit rate and video in general.
I don't really understand how I can use -fps 30 and the video looks
fast yet runs the same length as the normal movie.  Seems like it
would run out of images 1/2 way through the audio.  I must be missing
some basic understanding....





-- 
Bill Moseley
moseley at hank.org