video conversion from mp4 to flv problem

[Tapas Mishra]

I am doing a conversion of mp4 to flv on a GUI less server where I
have only SSH access.( I tried winff and X forwarding that had hanged
while doing this conversion so winff is not possible for me)

I do not have any idea of the
codecs,bitrate of this mp4 video.
Some one had converted from an m4v to mp4 and then uploaded this on the server.

When I tried converting on command line
as follows
http://paste.ubuntu.com/528113/
I had the above error.
I checked this page
http://www.ffmpeg.org/ffmpeg-doc.html
but I could not understand much.
Then I tried
http://paste.ubuntu.com/528114/
Thinking that libmp3lame was the problem I tried following
http://paste.ubuntu.com/528115/

Couldn't find package "libmp3lame".  However, the following
packages contain "libmp3lame" in their name:
  libmp3lame-dev libmp3lame0
Couldn't find package "libmp3lame".  However, the following
packages contain "libmp3lame" in their name:
  libmp3lame-dev libmp3lame0

So which one of the two I should try?
-- 
http://mightydreams.blogspot.com