WinFF - QMin/QMax : why 31 ???

[Klagar]

Hi,

That may sound a little silly, but I just like to understand precisely why things are the way they are.
Does anyone know why, in WinFF, when setting the -qmin/-qmax properties, the maximum number possible is 31 ?
A piece of robot to anyone who has the answer !

Thanks !

[filmboss80]

And what type of conversion / preset are we talking about?

WinFF is not the best frontend converter for those who need to make specific tweaks and customizations. I think the presets are based on common settings. For people who want uncomplicated, 1-button conversions, it is pretty good at what it does.

Perhaps it would help if you provided info on what kind of conversion you're trying to make.

It might also be more helpful to inquire from WinFF's forum.

[Case]

The quantizer scale for many video codecs is 0–31, thus giving 32 possible quantizer values (steps). 32 is a nice 'round' number in binary: 2^5. Thus, one only needs 5 bits to hold such a value. I suppose 32 quantizer steps was considered "enough" at the time when the encoding specification came to light.
The quantizer scale for MPEG-4 AVC / h.264 is 0–51, to allow specifying smaller steps. So it is not always 0–31.

[Klagar]

Here is an example of the kind of command line we use :
-vcodec wmv2 -b 8500kb -s 1280x720 -aspect 16:9 -r 29.97 -qmin 1 -qmax 31 -qcomp 0.6 -flags +loop+aic -me_method epzs -cmp +rd -subcmp +chroma -async 1 -acodec wmav2 -ar 44100 -ab 96kb -ac 2
I am primarily dealing with conversion from DVDs to web-adapted films, both for hi-res films and lower-res ones.
I don't know if that kind of conversion has been gratified with a name, I'm new to all this stuff. Or maybe that's not what you were asking, in that case could you tell me precisely what you're looking for ?

And though I would personally be curious to ask what could be your alternative to WinFF, I do work in a company in which 90% of products are based on WinFF. So personal interest aside, such an alternative is unfortunately not an option

I will inquire on WinFF's forum, as I inquired on a few more forums. In the best case I'll have a few complementary advices and will be able to forge my own point of view from there !

Thanks !

[Klagar]

@Case :
Thanks so much, that's precisely what I wanted to know !

[filmboss80]

I don't know if that kind of conversion has been gratified with a name, I'm new to all this stuff. Or maybe that's not what you were asking, in that case could you tell me precisely what you're looking for.

Well, until your most recent post (which provided the command line), we did not know that you were making conversions to a Windows Media file (as opposed to and Xvid, .flv, .mov, or DVD-related output). It was also helpful to know that your source was DVD (mpeg-2 based .vob), and that you're distribution is on the web.

For .vob-to-wmv, WinFF is as uncomplicated a tool as you are going to get. AviDemux may also be a useful tool for you.

I take it you are not really having a problem with the preset, but just curious about the quantizer parameters. And Case provided the answer.

[Klagar]

Thanks a lot FilmBoss, now I know what informations I should provide next time I've got some questions !