[MEncoder-users] documentation on x264encopts log=3 output?

Jeff Clagg snacky at ikaruga.co.uk
Tue Feb 21 17:12:52 CET 2006

On Tue, Feb 21, 2006 at 05:06:16PM +0100, Kris.Struyve at alcatel.be wrote:
> Hello, 
> Is there any documentation about the data that the option "x264encopts 
> log=3" sends to the command line? 
> Consider for instance 
> x264 [debug]: frame= 180 QP=26 NAL=2 Slice:P Poc:12  I4x4:229  I16x16:1053 
> P:822  SKIP:616  size=11690 bytes 
> x264 [debug]: scene cut at 181 size=17836 Icost:2445204 Pcost:2362526 
> ratio:0.966 bias=0.074 lastIDR:7 (I:2492 P:199 Skip:29) 
> What is the meaning of the NAL, Poc, P, SKIP and size columns? 
> What is the meaning of the info related to the scene cuts? 

These aren't formatted as columns.

NAL=NAL unit type
POC=Picture Order Count
P in this context means predicted macroblocks. On the second line
there, it's telling you there were 822 P macroblocks in this frame, and
616 skip macroblocks. Size is... size of the frame. The scene change
stuff is primarily of interest to anyone tuning either the scenecut
parameter, or x264's I-frame insertion decision algorithm.

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