DVD Analyzer

[jeff b]

There are a lots of software tools around to get information off a DVD that I've made, and sometimes I find myself resorting to these various pgms to try to figure out what might be different about a disk that, for instance, plays in all but one of the players I have in the house. But, more often than not, I end up shrugging my shoulders and coming away not really knowing what I could have done differently to have made the disk work in all players.

So, I wonder if anyone's come across a program that would analyze a DVD and provide information that would be oriented toward this type of quest. If I were to write such a program, I'd call it something like "DVD Coach".

Jeff B

[LvR]

I use KProbe and find it an invaluable tool in identifying rubbish media - you need to read all 24 pages or so of that thread to get the implications right.

Another good one is DVDInfo Pro - this one is a bit more extensive re info on all things related to media and writers on your system - I like this one too , and between the 2 I know all there is to know about my disks I write.

[Brian Ellis]

The problem you describe is a player issue, IMHO, not a DVD one. With pressed discs, the pit:land contrast is MUCH higher than with DVD±R/RWs. The latter, where the "pits" and "lands" are co-planar and rely on the different reflectivity of the photopolymer layer after exposure (±R, RWs being a metallic fusion), give a weaker signal between the 1s and the 0s. Different media may have slightly different mark:space reflectivity ratios and this is about all you can play with, although my experience also shows that burning at low speeds produces a sharper transition from the "pit" to the "land" and more reliable results. My advice there is to burn at no faster than half the rated speed, preferably less. For important work, I always burn at the minimum speed my burners allow.

Then there is another problem: the decoder in the player has to convert the digital signal into an analogue one in real time. Many of them, especially older models, baulk at this job, even with pressed discs, above 6000 kbit/s. With ±R/RW discs, the poorer signal quality sends them bananas at lower bitrates. I therefore recommend that you NEVER set the CBR bitrate over 6000 kbit/s or the VBR over 6000 kbit/s maximum, if you wish maximum compatibility with players. This may have the added advantage that the filesize is smaller, so that the outermost tracks are not used. As many players have constant-speed motors, the linear velocity on the outer tracks is far higher and reading reliability drops (plus there is more handling contamination likely on the outer tracks). I always aim to have filesizes <4.1 Gb for this reason, often only 2 to 3 Gb. If your input data are from DV tape, you will not lose any significant visual quality by burning at 6000 kbit/s. Only uncompressed video from a pro camera will lose in quality at this bitrate.

Hope this pragmatism will help, if a software doesn't.

[LvR]

Brian is right on most of those points, and because there can really not be any program that would know about the specs/limitations of any and all players while taking into account the current state of wear and tear on the units and also the laser degradation, I think the best you can do is to create a DVD on media in such a way that it can be reliably read with the lowest number of errors and the least effort by the decoder - all of which brings me back to those apps I mentioned.

Note : Nero now also has some of those tests built in under their "disk quality test"

[jeff b]

Thanks, Brian, that helped to explain more thoroughly what I've only intuited all along, not having read up on this subject at all. Generally, I've been careful with my own projects, and they've always been burnt to stay within the kind of boundaries that you describe, always coming out fine and playing on all the players in the house.

Lately, I've been capturing episodes of one or two series on TV, and these have been more highly compressed to fit a couple of hours on one SL disk. They actually come out really nice, but one player (Panasonic RP56) seems to choke and puke on about 50% of the ones I've done so far, and it's been annoying because that's the player I use in the living room. It'll probably be relegated to the "test pile" soon!

Lawrence, thanks for the links to those two tools... they'll come in handy.

Jeff B