Can someone explain to me the difference between Variable and constant? What are some of you peeps using with success? Does one give better quality than the other?

ROB

constant means that the bitrate of the entire film remains constant, while variable means that the bitrate changes depending on the scene. variable is the choice for higher quality, cuz more bits will be devoted to the areas of the film that need them.

Completely wrong explanation. See http://www.dvd2one.com/ratio.php for more info.

Erwin

"constant means that the bitrate of the entire film remains constant, while variable means that the bitrate changes depending on the scene."

AZImmortal's explanation is correct.

"variable is the choice for higher quality, cuz more bits will be devoted to the areas of the film that need them."

Still correct. Just a matter of opinion.

cheezz

FROM THE DVD2ONE SITE:

In general the constant ratio mode works better on long (2 1/2 hours and more) movies than the variable mode, because excesses in compression ratio will be more visible at lower bit rates. However, in most cases both modes will work fine, so you can choose the mode you prefer.


I guess this is a issue? I just used this the variable one with a movie and it looks good to me. Going to try it now with the constant and see if i can notice any difference..

rob..

I suggest you believe Erwin because he wrote this program

cu
braeutigam

If the original is encoded with variable bitrate, and you compress it with constant, the endresult will be variable as well, just because the process will compress everything equally (constant), which you can see clearely in the graphs (look at the peaks, they are on all the same places as the original).
So if you use constant bitrate, you will end up with a movie which look the most like the original (compression wise).

If you use variable bitrate on a variable-original, it will not look like the original, because it's variable on variable compression. It will use it's variable method again...

I'm no expert on this matter, and i do not know which will give you the best result, but i will use constant, just because it looks the most like the original and i think that the demand for bandwidth will be the same in the endresult, but again, i can be mistaken.

Rinkel

No one can 'know' in all cases...
It seems to boil down to this: it depends on the movie (and on whether you strip this or that, M-O or Full, etc.). The production-house engineer elects an engine and compression rate for given releases, and movies vary in both length and in content that favors digitalization/compression (depending on selections) such as dark-detail/rippling water/action-scenes/etc. To completely analyze any movie for all possible contributing factors leading to an 'educated guess' of Con or Var being the best would be a daunting task, and may also be dependant upon what the viewer appreciates most--sharpness in detail or absence of artifacts...
I used to complain there was too little guidance for making a choice, and grew impatient with answers like 'pear or a peach' or 'let your eyes tell you'. Now I understand that the question itself was flawed. I think Constant was developed to address a pulsating effect noticed by some, on some setups, and with some movies. It ended being neither better nor worse than Variable for all possible uses, so the guys at D2O risked the inclusion of both, so we could have a choice. It's not their fault that they can't legitimately make the choice for us.
Nature of the beast...

I find it a bit odd that the authors of DVD2One would consider the term "constant" as an option, as this is certainly not the case with original source material (which is clearly vbr). LOL, can you imagine the increase in movie size if original DVD's were authored in a constant bitrate? Perhaps a better term for this mode (and less confusing to some users) would be "matching" or "equal"...or something of the like.

Because "constant" is still the "constant" compression technique.
D2O will compress the source the same at all levels, the output is still VBR, but that is because the source is VBR.

The problem with the argument is that you are interchanging the terms "compression" and "bitrate". Please point to me where it states that the constant compression mode uses a constant bitrate. You are all confusing yourselves by mixing up the terminology.

Almost every single DVD you are ever going to buy in a store will have used a variable bitrate to achieve the image you see. If a DVD used a constant bitrate, the graph would just be a straight line! Why would anyone produce their movie onto DVD at 6000kbit/sec (for example) the entire way through? It makes sense to use less bitrate where it's not needed, and more where it is needed. The only time I've ever seen a constant bitrate video on DVD is on a short film, a demo, instructional video, or home movies where variable bitrate encoding is not needed.

The "constant" and "variable" compression modes in DVD2One determine how the existing bitrate is compressed. It does not change a DVD from VBR to CBR or vice versa.

In variable compression mode, DVD2One will assess where compression is needed using it's own engine, and apply it so. The end result will show a graph different to that of the original, because compression was used differently than when it was produced.

In constant compression mode, DVD2One will determine what level of compression is needed to achieve your desired destination size, then equally compress the entire video. The end result will show a graph identical to the original, except it will appear "squished" from top to bottom.

Now as to which one is better... listen to the developers, or decide for yourself because in the end it is a matter of opinion. It's not a yes/no or black/white question.

VCDmonger

I didn't realize this was an argument...

AZI's defined terminology is absolutely correct when encoding audio & video. LOL, and yes...the terminology for DVD2One's transcoding/compression process is a bit different. Surely, most of us users have seen the compression mode definitions and graphs. I think evdberg's initial response of: "Completely wrong explanation" is what sparked any debate on this thread.

Stop hittin' us with your 88's, monger. We surrender...

Well he may have written the Program, but he cannot change the definition of the words..

var·i·a·ble (vâr--bl, vr-)
adj.

Likely to change or vary; subject to variation; changeable.
Inconstant; fickle.
Biology. Tending to deviate, as from a normal or recognized type; aberrant.
Mathematics. Having no fixed quantitative value.

n.
Something that varies or is prone to variation.
Astronomy. A variable star.
Mathematics.
A quantity capable of assuming any of a set of values.
A symbol representing such a quantity. For example, in the expression a2 + b2 = c2, a, b, and c are variables.


con·stant (knstnt)
adj.
Continually occurring; persistent.
Regularly recurring: plagued by constant interruptions.
Unchanging in nature, value, or extent; invariable. See Synonyms at continual.
Steadfast in purpose, loyalty, or affection; faithful. See Synonyms at faithful.

n.
Something that is unchanging or invariable.

A quantity assumed to have a fixed value in a specified mathematical context.
An experimental or theoretical condition, factor, or quantity that does not vary or that is regarded as invariant in specified circumstances.


I admit I have not read the entire thread, but i got to this reply and thought What a dumb ass, No offense. If Viariable Means something other than A bitrate that is not constant and Changes to compensate for Frame Simplicity or Complexity and Constant means something Other than CONSTANT a variable that does not change for any situation then he should rephrase his Constant / Variable Option to say something else. He only wrote the program dude, he doesnt decide the definitions of words.


Yep, my post has absolutly nothing to do with anything. Sorry.. On another note:

GET YOUR ASS'S WORKING ON DVD2ONE! DVD2One was the First Click and Go DVD to DVD-R/+R program and now look you have worked so slow, worried about protection that is broken 20 minutes after you put the Prog in the download section, that every 1/2 assed software writing company and Freelance programer has written there own version that Boarders on kicking DVD2Ones ass, and 3/4 of these programs havent even had an upgrade or a patch yet so when they do there going to stomp DVD2One. Get a Lawyer and do some hiring of Coders. If you dont do something now DVD2ONE IS as GOOD AS DEAD!

Here we go again

This guy obviously likes Polls and the sound of his own voice.
Also seems like he knows the price of everything & the value of nothing.

If you dont like Dvd2one ....... dont use it .... it's simple.

Dont jump on other peoples threads, just because yours got closed.

Please stop wasting everybodys time ....... we are not interested in hearing your whinges & whines.

If you can manage to post, without being offensive and rude ... fine, otherwise dont bother.