Question about filesize in 2nd pass

[AdRaccoon]

I´m currently encoding some TV episodes, all about 45 minutes long.
For all episodes, I´m using the same Xvid parameters, and the "desired size" field in the 2nd-pass is 460000 KB. For now, I have encoded 4 episodes and all of them have different filesizes and though different Bitrates.
Why is that so? can I force Xvid to use the Filesize i want to have?

Thanks...

[Nic]

Hmmmm, what version of XviD are you using?

Also, you are doing two passes each time on every episode as well I assume...(sorry if that seems a dumb question, but you can never tell).

Also could you give a list of the filesizes your getting how much do they vary (are they just undersized??), also give a description of your encoding methods.

-Nic

[Imperial Llama]

Take a look at this thread. It's written for DivX 5 but it applies to XviD too:

http://forum.doom9.org/showthread.php?s=&threadid=24584

Also try searching the XviD forum for undersized/oversized files. Questions about wrong filesizes are asked very frequently and it's nearly always for the reasons explained in the DivX 5 thread.

[AdRaccoon]

Well, they´re aren´t really undersized (I assume), they vary between 449MB (=460000KB, the size I specified) and 398MB (The smallest so far). It´s not important, I´m just curious why they aren´t all the same size, since the episodes are almost the same lenght.

I´m using mostly the default values, because I´m not an expert on this stuff.

Motion Search precision : 6 - Ultra high
Quantitization Type : MPEG
FourCC used : XVID
VHQ Mode : 4 - Wide Search
...and "Use Chroma Motion checked"

thats all...the rest are default settings, and yes I´m doing all episodes the same way (2pass) with Nic´s Xvid build from 16/07/03

[Tuning]

Does each episode differ in darkness/motion(high/slow)??

[AdRaccoon]

Well, it´s Deep Space 9 and space is usually pretty dark...:-)

[Tuning]

So follow the fact that darkness(black) doesn't requires bits to show as black again!.i.e no bit allocation for black region.