xvid target size problems

[Cowabunga]

Hello,
I use virtualdub xvid codec to make an avi with a permanent subtitles in it.
I make a 2-pass encoding en the output file is always great quality.
exactly the file size that i want.
But now i use exactly the same settigns what i always do but the final file size is much lower than it should be.
I try it more than 10 times with different target sizes but i always get the same size.
I bring it back to the default settings and installed the last xvid codec but it's still not working.

I hope you can help me.

gr Cowabunga

[Baldrick]

How much lower? You haven't change any audio codec settings?

[John-Paul]

installed the last xvid codec

Sometimes AutoGK can be sensitive to upgrading xvid versions, try using the the xvid which is part of the AutoGK installation package, but unistall the xvid on your system first.

[John-Paul]

sorry, wrong thread.

[Cowabunga]

How much lower? You haven't change any audio codec settings?

no audio changes it's 40 mb lower than it should be

gr

[Cowabunga]

I try alot of things but it still get a 300mb file what shoud be 352 mb as always

[Cowabunga]

can nobody help me??

[hech54]

I get more accurate final file size with AviDemux personally. I use two pass final size and use the built-in calculator.

[John-Paul]

It may be a matter of trial and error to isolate the problem. Firstly, try uninstalling xvid completely before re-installing - its possible that overlaying a new version on top of an older one could cause issues, but perhaps you've already tried this?

Then, if you still have the original source files for some of your earlier xvid conversions that resulted in the correct file size, you could try to re-encode and compare the previous correct one (350 mb) and the new undersized one (300 mg) in Gspot or Media Info to shed some light on where the problem exists (ie: video bitrate, audio, subs, etc). That may help you narrow it down.

[Cowabunga]

I think i found the problem
If i use general purpose i get the right file size.
But if i use user defined i and make changes in the quantization from:
1
31
1
31
etc
to
2
31
2
31
it goes wrong
But is the quality of general purpose the same as user defined?

[manono]

The main reason quant 1 was introduced was to allow you to reach a desired size when the size requested was greater than you could achieve with quant 2 being the lowest. That is, you requested a size too large for the resolution and other settings you used, and the codec was unable to achieve it. You "saturated" the codec, as the saying goes.

What's the answer, without resorting to quant 1 to get the size you want? Raise the resolution. Use better quality audio (AC3 instead of MP3, for example). Use fewer B-Frames, or none at all. Filter less, if you're filtering. Yours is a typical newbie mistake.

[Cowabunga]

I have use this guid settings.
http://www.divx-digest.com/articles/xvid_setup_page3.html

[manono]

Yeah, so?

Quantizer Restrictions: - Apart from changing all Min quantizer settings to 2 (using 1 will not improve picture quality, and will only increase file size), you can leave the other settings alone

If it won't reach the size you want, then lower the size/bitrate. Doesn't it look very good, even 50MB smaller than you requested? You could also use better quantisation matrices to make a sharper and higher quality video, and that may allow you to reach the desired size, but many standalone players won't play videos with non-standard matrices.

[Cowabunga]

i have it working good now! thnx for the help