[MEncoder-users] Backup policies

[infernix]

Phil Ehrens wrote:
>> This is a naive question. I understand the above reasoning, I think, but 
>> surely if one performs 1-pass crf, one will end up with some average 
>> bitrate. Wouldn't a 2-pass encode with that same bitrate give better 
>> quality due to superior distribution of bits?
> 
> Going even a bit further, since bitrate is per-second, and not
> per-frame, isn't single-pass encoding always just plain wrong?
> My own experiments support this contention.
> 
> And a disingenuous reference to the entire doom9 forum as support
> is feeble.

This is what I thought first, but 
http://forum.doom9.org/showthread.php?p=996195#post996195 and countless 
CRF18 x264 encodes later, I'm only using 2pass if i need to squeeze 
something in a specific filesize :) you might want to go over the entire 
thread but just that post suffices. I do wonder how you did that 
experimenting, did you compare visually? or did you compare PSNR/SSIM 
values? what source at what bitrate? what are the QP results after the 
encode for CRF versus 2pass?

Besides, if you do go for 2pass, you have to make sure you are never 
undershooting, because then you'd have to encode it again at a higher 
bitrate.