View Single Post
Old 12th December 2017, 10:42   #21  |  Link
excellentswordfight
Lost my old account :(
 
Join Date: Jul 2017
Posts: 322
Quote:
Originally Posted by jd17 View Post
I did not know that is possible.
However, what would be the benefit?

Isn't one of the reasons to use a CRF instead of a bitrate target to be freed from any bitrate constraints?

I thought CRF uses whatever bitrate necessary for each moment to achieve a certain degree of quality...
If CRF uses whatever is needed - what difference would a 2pass encode even make?
CRF with maxrate and bufsize constrains would imo only make sense for big streaming services, the use of CRF there would not be to increase quality but to lower filesize (i.e. storage cost) without much of an quality loss for low complexity material.

So for 1080p24 streaming it would look something like this
Code:
--crf 20 --vbv-maxrate 9000 --vbv-bufsize 12000 --keyint 48 --min-keyint 24 --rc-lookahead 48
And agree, I dont see a good reason for 2pass CRF even if it's possible.

Nico8583, what are kind of playback environment are you aiming for? It sounds like CRF encoding with the lowest preset you find tolerable is what you are looking for. I would start at preset slow crf 18 and go from there.

Last edited by excellentswordfight; 12th December 2017 at 10:59.
excellentswordfight is offline   Reply With Quote