[FFmpeg-user] formula for transcoding to ogv, shrinking an mkv

[James Miller]

On Fri, 18 Jan 2013, Carl Eugen Hoyos wrote:

> The MEncoder documentation is old and therefore by
> definition a bit out-dated but it contains many
> information to basic strategies:
> http://www.mplayerhq.hu/DOCS/HTML/en/menc-feat-dvd-mpeg4.html#menc-feat-dvd-mpeg4-2pass

Thank you for providing that link, Carl. I've looked over the information 
and learned a bit more. In summary, it looks like 2-pass (or multi-pass) 
encoding serves the function of minimizing file size while preserving 
maximal video quality. And it is something along those lines I'd like to 
do with my screencast files.

But as I read over that information, I note that it seems to refer mostly 
to production movies. It speaks, for example, of action scenes, which can 
apparently require higher bit rates than non-action scenes. On reading 
that, I realize that the screencast files I produce are quite different, 
and I am left wondering how applicable the material is to my scenario.

In overview, what I am producing are lecture files. I capture the input 
portion of a drawing program window, which I use as a kind of whiteboard, 
typing in occasional words or phrases as I speak. At intervals I erase the 
content and start typing there anew. The result is that there is actually 
very little change in the content of the area I am capturing: several 
minutes may go by when nothing at all is typed into the area and so no 
video changes are occurring. That visual scenario is, of course, much 
different than a production movie--action or otherwise.

I don't know whether that further explanation of the nature of my 
screencast files will have any bearing on which transcoding method I 
will need to use. But it seemed worth noting.

James