[MPlayer-users] mencoder 1 pass and 2 pass encoding diference

[marpet at linuxpl.org]

On Wed, 7 Nov 2001 16:26:57 -0300 (ART) Leandro Lucarella <leandro at lucarella.com.ar> wrote:

> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html &
>  http://gcc.gnu.org/gcc-2.96.html if you still have questions or problems]
> 
> Hi! I'm sorry about the lammerez, but, what is better for quality, 1 pass
> or 2 pass encoding?
> what is the diference between this 2 methods?

basically first pass of 2-pass mode is the same as in one-pass mode,
additionally you store some statistics from the encoding process
(like amount of bits used for various things for each frame).
In second pass you read those stats and encode the frames accordingly
(in orded to distribute bitrate through the stream more inteligently)
Thanks to that valuable bitrate is not wasted on parts of the clip
where not needed and can be used in more requiring moments.

The downside is that 2-pass mode takes twice the time (you make 2 full
encodings). The big advantage is very constant quality throughout the
movie clip. The other advantage is that you can predict clipsize more
accurately than in single pass mode.

regards

-- 
Marek Pętlicki <marpet at linuxpl.org>
Linux User ID=162988