Movies too large...

[orm]

I use Xmpeg 4.2a with the DivX 4.11 codec and my movies come out about 20megs larger than they should be...
My bitrate calculator says I should use 617kbps for a 126min movie (25fps) with 160kbps joint stereo MP3 audio to get 700Mb with DivX 4.xx codec.
When I do this with simple 1-pass encoding and with black borders cropped the filesize ends at 743398kb (725Mb).
The only thing I can think of (but I haven't had time to try it yet) is that it is because I have set the "Normalize Audio" setting to 180%, but that shouldn't affect the file size should it? If it does how do I calculate the correct bitrate?

Any suggestions?

Please!

[Jacksindecision]

I have had similar problems with bitrate calculators. These calculators are not 100% accurate and give a general estimate as to what the bitrate should be. An extreme example: when I converted my copy of Ghosts of Mars to divx, the bitrate calculator told me 1900 kbps would give me a 1.4 gig file. However, I was able to set the bitrate at 6000 kbps and got a file only 977 mb. This is an extreme example of the calculators inaccuracy. However, most of the time the calculator is fairly accurate and it just takes some time to figure out the proper adjustments on the bitrate calculator's calculations. You get the hang of it eventually.

[orm]

OK, this is strange because I have done this a couple of times before and never had any problems, but that was with the old Flask 0.6 (I think) and DivX codec 3.11.

[benderman]

It's because of the low bitrate. With bitrates lower than 800kbps the resulting bitrate is often bigger than the calculated. Maybe you can reencode the audio to 112 or 128 kbps or cut of the end-credits.

[orm]

Aha! Thanks! My problem is that I hate changing CDs in the middle of a movie so I have to live with low bitrates and problems like this...
I guess I should try 2-pass encoding but then I guess I still have the problem to calculate the bitrate for an optimal filesize.

[Homerlovesbeer]

Nandub has it's own inbuilt bitrate calculator that I think gets it's info from the 1st pass file it creates. It pretty good. Select audio file you are usiing and filesize and it calculates pretty accurately.

This is my understanding anyway

cheers
Homerlovesbeer

[Baldur]

Well, it seems that nobody knows it, but your problem isn't due to bitrate calculators inaccuracy, nor to bad xmpeg settings.
It's due to a substancial difference between divx 3.11 alpha and 4.11
Simply:
3.11 considers 1 KB = 1024 bytes
4.11 considers 1KB = 1000 bytes
so you should use an appropriate bitrate calculator, like the one u can find there:

http://spark6.vr9.com/DivX4BitRate.zip

Hope this will be helpfull. Bye

[orm]

I know that. I use DivX 4 Bitrate Calculator and the size gets wrong anyway

[orm]

I just read in another post that the bitrate varies a bit throughout the process (I just made a test and thats exactly what I saw...)
So this is probably the problem here, if I have a low bitrate these fluctuations will affect the final filesize to a greater extent than if I have a high bitrate.
So now is the question: why does the bitrate vary? Is it the same thing with older codecs?

[Baldur]

Well, divx codec is a VBR codec. That means that it varies the bitrate depending on what's needed.
For example if it encounter a static scene, it'll decrease the bitrate usage, becouse it has to store a lower quantity of datas, on the other side, if it encounters a scene with high movement, it'll encrease the bitrate, sometimes to values higher than the one u set!
That's the reason why older 3.11 had high and low motion.
The bitrate usage, depends also from the kind of images. I mean, if images ar dark (like Sleepy Hollow) the bitrate will be a little bit lower thanif images ar bright.
So if you're handling an action movie, maybe u should set your bitrate to a lower value. But there isn't any general rule. U'll learn to set the right bitrate as much as your experience grows. You have to consider what kind of movie you're tryin' to compress.

[orm]

OK, thanks a lot!