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

[James Miller]

On Mon, 21 Jan 2013, Lou wrote:

> It's your choice and you can have both on one machine. There are
> several methods to do this such as what Carl proposed. Just be aware
> than when you issue the ffmpeg command that you're using ffmpeg from
> FFmpeg and not the fake version supplied by Ubuntu. You can tell what
> you're using by looking at the first line in the ffmpeg console output:
>
> ffmpeg version N-48755-gd9226b3 Copyright (c) 2000-2013 the FFmpeg
> developers
>
> Real ffmpeg says FFmpeg in the line. Another method to determine what
> you're using is that avconv from the repository has more bugs.

Thank you for the further clarifications, Lou.

> Where did you get 191k from? Is it arbitrary? You can roughly predict
> the output size as shown in the x264 guide but I'll repeat it here:
<snip>

The 191k is fairly arbitrary, yes. I decided, after trying the incantation 
you'd previously proposed and seeing that it did not sufficiently shrink 
the output file, to try something a lot lower (so I lopped off the final 
digit). Also, I seem to recall reading somewhere that a default bit rate 
is 200k, but I can't recall now where (or if) I came across that. In any 
case, the output winds up being of acceptable quality for my purposes: 
does that number seem to you too low?

Thanks for the further explanation on how to reduce the output to a 
certain size.

James