Help with WinFF parameters

[Klagar]

Hi everyone,

I started a new job which requires me to dive into video encoding, a topic about which I've never given much thought. So now I am full of rather-newbie questions, trying to catchup with the train and become an expert in this field in as little time as humanly possible.

So here are my many questions. I just want to understand a little better those parameters in WinFF. I've checked the documentation available on their website, but it seems rather incomplete and vague.

Let's take a very real example which I have to deal with, and I hope someone out there can impart me some wisdom.

Command line :
-f avi -vsync 1 -vcodec libxvid -r 29.97 -s 1280x720 -aspect 16:9 -b 15000k -qmin 1 -qmax 31 -qcomp 0.6 -flags +loop+4mv+aic -me_method epzs -cmp +rd -subcmp +chroma -g 10 -async 1 -acodec mp2 -ab 192k -ar 48000 -ac 2

Questions :

-vsync : can anyone explain what could happen to a video file that has this parameter set wrong ?

-qmin/qmax : why is the maximum number permitted 31 ?

-flags : what is that ?

-cmp/-subcmp : what is that ?

-g : what values would you recommend ? Is there a value over which the video will inevitably lose a lot of quality ?

That should be it for now. Thank you for your time !!!