Oh yes Oriphus - quite right, done a little diggin and totally agree with what you said - something was whirring in my tiny little head and I thought I was sniffing at something.... Also, the skipping/freezing issue could also happen with fluctuations of the overall speed of the motor - with a VCR you hear the volume pitch slow up or speed up, but with a dvd player this would cause misreads and buffer under runs. Now as the dvdrom operates on a closed loop system (feedback), then weaker areas of the dvd will cause slower/quicker speeds rather than a uniform speed - and this is 99% down to the media...... But still a very interesting thread - cheers for the gen...
hi Load (NTSC).mcf then load the "unlock" template one folder down from the folder the first template is in! thx..
hi umm? wouldnt spin speed on watching main movie be the same through out? and laser travel speed changes? along the guides? Thx..
Yes, the spin speed should be same throughout but as the laser travels to the outer circumference - the speed may need to be altered ever so slightly because: The inner circumference travels slower than the outer circumference (like athletes on a running track - the outer track lags the inner so therefore they look as though they get a head start).... So the speed may actually change ever so slightly in order to keep up with the streams... Again spit-balling a little but just trying to fit some pegs into that square hole.....LOL
Actually, i hate to be a painj in the ass and disagree. lol I was under the impression that the spin speed is constant, depending on the quality of the media (there might be some variation). What i understood was that the DVD Spun constantly and the laser on its track moved progressively slower as it went along due to the ever increasing circumference of the the disc. That way, it could deal with the smaller (inner) end of the disc at the same roational speed as the larger (outer) end of the disc. Thats my understanding of it anyway. Your right Paul, it has been a really interesting thread. Wonder who can put us all straight on it lol Chris
[bold]Wonder who can put us all straight on it lol[/bold] You can say that again as i have no idea what i am talking about - LOL MUHHAHAHAHAHAHA HELP !!!!!!!!!!!
Okay, I now understand that using variable ratio yields the best quality. So when or where would you use constant ratio? I mean, it has to be there for a reason, right?
My understanding of when you should use constant or variable ratio is that its a judgement call on your part. A film that is two hours long and is compressed (movie only) at constant ratio may show virtually no sign of having been compressed -> thus, use constant and be as happy as you have always been with DVD2ONE output. A three hour long movie, on the other hand, has always been cause for debate about the quality of DVD2ONE output. Films like Gladiator or The Lord of the Rings reportedly show signs of quality deterioration when run through at constant ratio (as the older verions of DVD2ONE all used constant only). If you are one of those people who believed that DVD2ONE's quality was unacceptable on these long films, you now have the choice to use the variable option and allow more data to be allocated to the complex parts of a long film that would otherwise show deterioration. I haven't actaully used the variable ratio option yet, but my understanding is that the quick scan of the disc that v1.20 does is meant to give the program an idea of where the most complex parts of the movie are, and thus allow for less compression of those areas at the expense of lower action sequences (or the credits). Choose your own cutoff point and use constant for any films under a certain length, and variable for those over that length. Or, like I said above, if you have always been happy with every movie that you have backed up, don't worry about it and keep using constant.
Very good, guys. Thank you very much. By the way, baabaa, how did those data rate tests go with your brother's Cyberhome thingy?
Returning to the original question of whether variable or constant compression ratios are ideal, I have made a few observations. The variable compression setting does not work well with movie scenes with very little action or dark picture. During these scenes, the bitrate jumps around too much making the picture seem to come into and out of focus every few seconds. From my experience, it is best to use constant compression whenever possible, namely on shorter movies, and variable only on long movies. Has anyone else experienced a similar problem?
Actually, DVD Shrink is constant ratio compression and the next release v2.4 ot in a week or two, will be as well.
