[plug] Transcoding MPG

[Timothy White]

On 8/4/05, Onno Benschop <onno at itmaze.com.au> wrote:
> Stuffed if I can figure out how to do this.
> 
> I have a 40Mb .mpg file (which goes for 4 minutes.) It features a 44KHz
> stereo audio stream and comes from a business card CD.
> 
> I (think I) want to do a two-pass transcode using ffmpeg, but I cannot
> seem to make it work. I want to get it to the point where the .mpg is
> transcoded into a 5Kbit/s stream - to make it web-downloadable, but I
> cannot figure out what I'm doing wrong.
> 
> Can anyone either tell me what I should be doing, or point me to a URL
> that describes the process?

Ok, I'm fairly new to this as well so I'll give it ago.
Basically if you can play the file with mplayer, you /should/ be able
to transcode it to another format the mplayer supports. In the
mencoder command line you'll need to tell it to use ffmpeg, a quick
look in the man pages suggests you need to set vcodec to ffv1 using
the -lavcopts option. There are various options for setting audio and
video bit rates. As for two pass, i've no idea. I know it's not just
encoding it twice, it does a pass then comes back and optimises it now
that it knows what future frames looks like. How to do this with
mencoder I've no idea. Try googling on it. Or just play around with
mplayer and mencoder for now.

Hope that gets you started

Tim