About Matrices, Mr Anderson.

[m1ckran]

I've only recently discovered DVD Rebuilder and, on the whole, I think it's superb. One thing, though, is a total mystery to me: matrices. :confused:

I've read many discussions about matrices but I still find the subject puzzling. I suspect I'm not the only one.

Could some kind soul produce a sticky (for the benefit of people like me) that describes what a matrix is, how it works, why we should consider using alternatives, how we create an alternative, and what on earth is wrong with the default matrices anyway?

I know I am showing my ignorance and perhaps such a sticky would be too tricky or controversial to produce but I for one would appreciate it.

m1ckran

[steptoe]

True, a simple guide to what matrices are better than other

From what I've managed to understand there are many choices dependant on the source, but a simple approach of what matrices have shown to be better than the others would help

Say :

Animation
bitrates between xx and xx

[blutach]

Download and install Rockas' Rebuilder Matrix Editor and play around with it - there are good descriptions of various included matrices and what typical situations they are used for.

It can also be used to encode little bits of vid so you can see the output and quickly choose what's best for your movie.

Regards

[m1ckran]

Thanks blu.

I haven't got the editor yet although I've read about it. I hadn't realised that it includes the sort of information you mention. I'll try it.

m1ckran

[jdobbs]

The problem with matrices is that it is getting into the "guts" of MPEG encoding. So trying to explain how they work is difficult without first an in-depth understanding of how MPEG compression works...

But using matrices is fairly simple. Different sources work better with different matrices. Also, different matrices can produce better results at different bitrates. The names of the selections on the menu give you an idea of which are better for different situations... Low Bitrate works well for "low bitrate" situations, etc. In the future I may also add the ability to select matrices for special circumstances like animation or computer graphics.

It's kinda like adjusting the timing on your car... you don't have to understand that it is adjusting the position of the piston in relation to a point at which a spark is created and where the action falls in the compression cycle -- you just make sure the marks line up.

[m1ckran]

Thanks, jdobbs. :thanks:

Good answer and along the lines of what I already suspected. To me, it seems that matrix evaluation is very subjective and depends upon several unpredictable factors, which makes any definitive assessment difficult.

I still don't know why I should consider replacing your defaults. Perhaps I will have a better idea when I download the editor.

By the way, please consider making your reply the basis of a sticky. I'm not suggesting a noddy-guide, more of a point-in-the-right-direction guide.

m1ckran

[Harrysmiith]

I hope this is not going off Topic but I'm doing as blutach suggested and installing Rockas' Rebuilder Matrix Editor. Had some fun with missing mssstdfmt.dll
and comdlg32.ocx but now seems ok.

My question concerns Zulu Dawn Region 2. I have now looked at 3 originals and all suffer at the end of the movie - nightime, fire, smoke undot() and deen() have helped. HC seems better than CCE basic and now I'm looking to see if a change of matrix will help.

Has anyone else had any success with this movie ?

[blutach]

Check out this guide from UncasMS - http://forum.digital-digest.com/showthread.php?t=55613

Shows how to install and use filters and test segments with RME.

Regards

[johnhamler1]

personaly, I dont want mess with filters, Idont see the point to change an original.
if i have a dvd with a grainy picture, I want keep the visual aspect of the original.

so far so good. I use the qlb matrix for low bit setting and mpeg for higher setting.and HC as an encoder, and it works perfectly.

yes, jdobs, it would be cool to see a "cartoon" setting for dvd rebuilder.or a setting for low, medium, high action movies.

[FredThompson]

Filtering can be useful if you have a really poor transfer. Done properly, they should be similar to a good digital frame cleaner/stabilizer on prosumer equipment. Done improperly, they'll change the nature of the source instead of removing extranneous junk. Proper filtering should give you a better result on noisy sources than no filtering because the source images will be "cleaner" so more of the storage is actually representing the source you want, not the "dirt."

Matrices are a way to specify to the encoder what to "throw away" from each frame, for lack of a better phrase. Raw video is quite large so reducing the size is done through pattern analysis and removing redundant information. Having said that, the matrix is not he only component in making these decisions about how to reduce the size of the data inside the encoder.

[feedback]

personaly, I dont want mess with filters, Idont see the point to change an original.
if i have a dvd with a grainy picture, I want keep the visual aspect of the original.

I hate grainy pictures and I will change them at every opportunity.
Just my 2 cents.

Regards,:)