Trying to get the right size

[millekink]

I'm trying to encode billy elliot with the XviD Codec.
I followed the guide from doom9 but my final movie is about 60 meg smaller.(That are a lot of details missing :) ) I also tried to recalculate with the Xvid calculator.

Is this normal? Or is there a catch in the calculating process.


Thnx

Millekink

[iago]

@millekink

Please provide more information (length of the movie, resolution/resize, aimed video size, 2pass encoding?, your parameters, which build you use, etc.). It may probably be "saturation of the codec"?..

iago

[millekink]

Well it's Billy Elliot.

Duration: 1h 45min 49 sec
Resolution: 512x272
Desired size: 1cd
codec: XviD nic's bins.

Gk says that my movie size should be 611448Kb (598 mb)
but my encoded movie is about 531 mb.

What is codec saturation?

Thnx for the reply

[rui]

I don't know the tecnical explanation, but here goes :):
codec saturation happens when you have choosen a certain configuration on your encode parameters that originate a situation where the codec simply can't improve the encode anymore, and you get a undersized final avi.

For instance, the resolution too low, using filters that help the compression, a movie that is very compressible (very dark or very bright) and small, all this leeds to a situation that, even if you have choosen a higher final size, the codec simply can't atribute more bits to each frame, because, with the choosen parameters and the source movie, it's already giving each frame the max bitrate it needs.

As always, the experts are very welcome to step in and correct my mistakes. ;)

[iago]

@millekink

Well, it sounds really strange (67 mb undersize? :)) because XviD is absolutely very successful at hitting the target size precisely. And, saturation of the codec means the whole movie is encoded with the best possible quality (using only quantizer 2) with the settings you choose. However, it doesn't seem to be the case here according to the information you provide (though I haven't encoded that movie and therefore don't know much about its compressibility).

Maybe just check all your settings again to make sure that there is nothing wrong with them, and go for another 2-pass to see the result. (Then, accordingly, perhaps increase the resolution and use neutral/sharp bicubic resize, etc.)

regards,
iago

[manono]

Hi-

I think he probably is saturated. I'd suggest doing it over with a higher resolution.

[Koepi]

Heh.

I ripped that movie about a year ago for a good friend & neighbour (she loves that movie, I didn't even watch it once), that time still with SBC.
I was tempted to raise resolution to DVD level...

It's _very_ compressable, without filters.

And yes, your idea of "saturation" is absolutely correct and even technically speaking you can't improve the explanation, it's just that a first pass can't be smaller than a second pass in XviD (the curve treatment is coded that way).

Best regards,
Koepi

[millekink]

Thnx everybody.
Now I got the right filesize.

I'm verry happy with the result and I think I will leave Divx 4.12 for what it is and use XviD from now on.

I do see some artifacts arround edges but that 's ok.
Is it possible that I don't get them if i don't use "modulated" in the second pass. (I used Doom9's guide)


Thnx for the help


MilleKinK