[MEncoder-users] 2pass: auto-calculation of bitrate?

[Michael Rozdoba]

RC wrote:
> On Sat, 13 Oct 2007 04:12:45 +0000 (UTC)
> Ilya Zakharevich <nospam-abuse at ilyaz.org> wrote:
> 
>> D) And now the last logical step: If of these 99 remaining videos 40%
>>    is "action-like", 40% is "arthouse-like", and 20% is animation,
>>    then law of big numbers starts to be applicable.  Essentially, I
>>    won't need to have summaries of the particular videos; I could feed
>>    in 40 copies of "average action-like summary", 40 copies of
>>    "average arthouse-like summary", and 20 copies of "average
>>    animation summary".
> 
> This is certainly not workable.  There is no average "action" movie.  In
> fact, trying to classify the visual complexity of movies by loosely
> defined genres is a good sign you don't understand what you're doing.  

Still, the preceding ideas were interesting.

Perhaps a simpler more workable approach for choosing an average bitrate 
in advance to give each project similar quality would be to attempt to 
calculate compressibility before the full encode?

AutoGK does something along those lines. I think it constructs a sample 
from the source (around 5% of it), encodes that & uses the result to 
guess at compressibility (which it uses to choose resolution to give 
acceptable quality at a specified bitrate, but one could use the info to 
choose a bitrate).

-- 
Michael Rozdoba