I am new to dvd2one and am familiar with how variable and constant bitrates work. However, I need some assistance.
This past weekend I have done some extensive testing/comparisons with dvd2one and Clone DVD. I have found that dvd2one produces 'slightly' better results than Clone DVD for any movie, long, short, with or without menus. My main question is why are menus blocky for long 2 to 2 1/2 hour films when using the variable bitrate?
Constant bitrate produces better looking 'movies' even when doing full disk copies. However, the menus are generally compressed too much and look terrible, even for short 1 1/2 hour flicks.
Variable produces much better looking menus, still great quality movies, but for the longer films the menus are noticeably blockier even with stuff like audio/subtitles removed?
I must say though, Clone DVD lets you do episodes and has quite a nice GUI, but still does not produce the same quality as dvd2one. So it looks like variable for full disk copies. Constant for movie only or full disk copies, provided you can put up with blocky menus but a fantastic quality film. What do you guys think?

I have (for the first time) encountered the menu blockiness and fuzzyness as well with one film;

Entrapment

used DVD2one v1.20 (constant, full-disk) and Nero as I use with all of my compressed movies. The movie and other extras are very good. I would not try variable because I want the movie to maintain a constant bit-rate. I would first view the bit-rate of the original image with Power-DVD and/or my Sony Player. Typically the processed movie would be about half of the originals BR. Thankfully the developers of DVD2one are constantly refining their product per the user populations input.

One of the DVD2One fellas online can probably confirm this, but the impression I've gathered over the last few weeks is this:

DVD2One identifies which track is the main movie, and allots a higher quality rate to that video. Extras and menus are considered more expendable, and so get crunched more to save as much space as possible for the main movie.

Now that VARIABLE and CONSTANT are introduced as options, thing have changed a bit.

VARIABLE is the original compression hierarchy as described above. Some scenes (or video tracks) get heavier compression depending on whether DVD2One thinks it can take it, and most of the time does a fine job.

CONSTANT more closely follows the source disks peaks and valleys of encoding quality. Instead of favoring just the main movie so much, everything on the disk is coded at more or less the same percentages compared to the original material (which is not to say that it's the same numeric encode throughout -- when the source codes high, so does DVD2One, and when low, it goes low, etc.).

It's a different ball of wax than the CBR/VBR bitrate options we're used to from direct encoding. Even movies compressed with DVD2One at CONSTANT setting show lovely graphs of peak-and-valley bitrates, if the source material had 'em.


So, why is VARIABLE recommended for full-disk backups? Because it's designed to donate more quality space to the main movie, and squash the hell out of the rest of the disk.

And CONSTANT for movie only? Because you'll want the best quality for that one track, and DVD2One relies on the wisdom of the original encoding rates to determine how much to compress each frame.



It's also very true that quality depends on the source material. I've made brilliant backups of 3-hour movies that look fabulous, because the video was prepared so well. And I've made (and rejected) awfully scrubby backups -- often from DVDs of older television sources -- that are only 90 minutes but are as blocky as, well, a really blocky thing.


ReneB, does that sound about right?

That indeed sound somewhat right, DVD2one does the bitrate alloction on some form of natural selection. It detects the large part and automaticly adds a part of the free'd bitrate (by removing soundtracks) to that part and spreads the other part to the rest of the data.

Whole disc copy does a form of prescanning of the files to be processed so it knows beter where an advantage can be gained and where to leave the bitrate as is to maintain quality.

Menu's are a complete different ballgame, the data in there is so different from normal movies streams. So compressing menu's is the most difficult part, and we need to do some tweaking in that part, but detecting scene changes is not as easy as it sounds