VAQ and MPEG quantization matrix?

[KikeG]

I've read that VAQ should only be used with H.263 quantization.

However I've tried using it with MPEG quantization and there's also a size advantage. On a 17 sec. clip of already encoded video of Monsters Inc., encoded at constant q=3, there's a 7'4% size advantage using H.2.63 and a 6,9% size advantage using a MPEG quantization matrix.

As I see VAQ increases quantizers in areas with higher detail. I don't understand why this works any different with a MPEG cqm. Maybe it is because with VAQ quality can suffer more in case of MPEG cqm?

Thanks.

[Dark Shikari]

I've read that VAQ should only be used with H.263 quantization.You read wrong.

[KikeG]

I don't think I read wrong, however I didn't read it from you. Anyway, thanks for the clarification, it's what I wanted to know.

[Dark Shikari]

I don't think I read wrongOne could define "reading something that is wrong" as reading wrong... ;)

[Sharktooth]

using a custom quantization matrix with VAQ may lead to unwanted results. but that depends on the matrix.

[flebber]

using a custom quantization matrix with VAQ may lead to unwanted results. but that depends on the matrix.

Other than trial and error, is there anyway to predict when a matrix and VAQ combo will cause error?

[KikeG]

In case of MPEG quantization matrix, what unwanted results?

[Gromozeka]

Mpeg matrix with VAQ give good result, but VAQ with ZSM matrix jawor-a - very bad result
mpeg matrix q3 with VAQ very good too

[henryho_hk]

Sharktooth, would you please share your opinion or experience of your MPEG-4 ASP Custom Matrices with VAQ? H.263 is really a bit too soft.

[Sharktooth]

@henryho_hk: i no longer use xvid for my encodings since years.

@KikeG: i said CUSTOM quantization matrices (MPEG matrix is not "custom"...).

[BigDid]

Sharktooth, would you please share your opinion or experience of your MPEG-4 ASP Custom Matrices with VAQ? H.263 is really a bit too soft.
@henryho_hk: i no longer use xvid for my encodings since years...
Hi,

I am actually testing some CQM (custom matrixes) to replace standard matrixes for xvid encoding; more in the different AutoGk threads..

When I will have finished my tests I could share my experience; Atm it is just an opinion ;)

To the point, usually MPEG is a little more compressible than H263 and sharper but H263 is still excellent for anim or 3D-anim
So if you want sharp or more sharp, less compressible than H263 try Eqm V2 (AutoGk sharp) and Eqm V3 HR
If you want more compressible and still sharper than H263 try Eqm V3 LR and/or Eqm V3 ULR

My first tests shows that all CQM from Sharktooth behaves well with VAQ and that gives me the opportunity to thank him for all the worK done :)

Did

[Sharktooth]

that was... unexpected, however im happy they dont screw up...
on a sidenote eqm v3 ULR is obsolete since LCD displays. the reason is the "artificial" sharpening becomes an issue with high-contrast displays.
it is still valid if you have a CRT monitor/TV though...

[BigDid]

that was... unexpected, however im happy they dont screw up...
Hi Sharky, you're the man!

... on a sidenote eqm v3 ULR is obsolete since LCD displays. the reason is the "artificial" sharpening becomes an issue with high-contrast displays...
I persist; have done side by side 1 comparison with Jawor 1cd and ULR, some differences, but both are usable for that kind of extreme compressibility (ULR_VAQ is more compressible than Jawor_VAQ), seems VAQ rubs the artificial sharpening (even if ringing or artifacts still present).

I have not tested your UHR and EHR but Didée 6o9 seems to give excellent results with VAQ.

Did

[henryho_hk]

seems VAQ rubs the artificial sharpening

Perhaps VAQ saves enough bits to allow for lower quantizers.

I really hope that there will be XviD 1.2.2 which officially incorporates VAQ.