Undersized rip of Vampires

[glenn]

I've been having trouble filling a whole cd with this one... :) The settings are identical to two previous encodes that came out perfectly fine and on size, which makes the whole thing all the more mysterious...

The source is the Columbia Tristar region 2 dvd of Vampires, and is identical in all of scandinavia, the uk, and Germany (at least). If anyone else has the ability to do a test encode of this to verify if it's a 'problem' with the source or with my settings, then I'd be grateful.

These are the settings used... (using a modified edition of kilg0r3's settings box, previously posted on this forum):


GLOBAL | Q-ization | TWO-PASS | ALT-CC
---------------|-----------|----------------|----------------
MSP 6 | IF-MinQ 2 | 'Old' CC - | Use Alt-CC +
Q-type H263 | IF-Maxq 31| IF-Boost 0 | Aggr Medium
FOurCC XVID | PF-MinQ 2 | Below IF d 10 | HighDist 500
IF-MaxInt 300 | PF-MaxQ 31| IF bitr red 30 | LowDist 90
IF-MinInt 1 | BF-MinQ ? | -------------- | Auto MRQ +
Lumi - | BF-MaxQ ? | HighBR Sc 25 | Strength 30
Interl - | | LowBR Sc 10 | Manual MRQ n/a
Greyscale - | | PayB Delay 250 | Auto BBC +
-------------- | | PayB Type BIAS | Manual BBC n/a
Max BFs 2 | | -------------- | ---------------
BF-QuR 200 | | Hinted ME - | MaxBR 10000
Packed BS - | | | Min/MaxOF 60/60
DX50 Comp + | | |


I first encoded for a video size of 633854k (619mb), and the file came out at 470mb. I added a hundred mb to the size (733854) and got a file at 473mb. Finally I decided to try a size of 1000000, and got a resulting file of 483mb.

For the record, the movie is very dark and should be highly compressible, but I've honestly never come across something that COULDN't fill a cd... :)

Any ideas?

[Acaila]

Please direct your attention to the following two links:
http://forum.doom9.org/showthread.php?s=&threadid=24584
http://forum.doom9.org/showthread.php?s=&threadid=35859

I guess now that B-frames are in, we'll be seeing a lot more threads like these :)

For anyone else that gets undersized files, please search around before posting, this has been discussed a lot in the past. Maybe not in the XviD section, but it has in the DivX5 section.

[glenn]

I _did_ search the xvid section beforehand, and I was aware that bframes COULD mean size prediction got screwed up. However, I did make two other encodes, with bframes enabled, that were spot-on (698mb and 697mb going for 700), with the same build.

For the record, I used uManiac's instant build of 21.10-2002.

I did another encode, this time with 2000000 as size... and the file grew to 519mb :) Guess I'll have to include the director's commentary to fill the cd...

The quality is very good, by the way, I viewed the entire encode I did with the 1000000 encode, and I saw _no_ visible artifacts.

edit: I resize to 640x272, neutral bicubic, by the way.

[Acaila]

I was aware that bframes COULD mean size prediction got screwed up.Size prediction is not screwed up. It's just that once the file has reached the maximum possible quality, it just can't be made any bigger. It's not like the codec can fill the extra space with zeros just so it reaches the filesize the user wants.
Sometime the filesize kinda "wobbles" around the maximum filesize when you use different bitrates (that are all higher than the maximum it needs), this is a result of the 2-pass mode.
However, I did make two other encodes, with bframes enabled, that were spot-on (698mb and 697mb going for 700), with the same build.With this you are implying that you believe it has anything to do with the build you used. It does not. Getting an undersized file is the direct result of increasing the compressibility, which smoothing filters but also B-frames and QPel do. This phenomenon is movie specifc, not XviD build specific.

[glenn]

OK, I guess I can just assume this is as high as it will go with current settings then. Guess I'll just up the audio quality a bit, and be done with it :)

I do not apply any smoothing filters, just the resize, so I guess b-frames is what does it.

Thanks for your help Acaila!

[Koepi]

lower your bframe ratio to 150 or 100. Second pass can't be made much bigger than first pass.

Regards
Koepi

[HarryM]

Originally posted by glenn
OK, I guess I can just assume this is as high as it will go with current settings then. Guess I'll just up the audio quality a bit, and be done with it :)

I do not apply any smoothing filters, just the resize, so I guess b-frames is what does it.

Thanks for your help Acaila!


You have rip at max. compressibility now (Q=100%, all quants=2). You can't get bigger file principially.

You can:

Don't use B-frames (from -10% to -30% compressibility down)
Use Q-pel (from 0% to -2% compressibility down)
Use sharper resizer, e.g. sharp bicubic or Lanczos (cca -10% compressibility down compare to neutral bicubic)
Use MPEG quant (cca -5% compressibility down)
Use lower I-interval
...