magicdiscoman wrote:then it 99% laser missalignment especialy if you have problems with the cheap martial arts movies there non coded too.
Hmmm... I think alignment is an entirely different problem... which is almost akin to the old 'Azimuth' alignment of old cassette decks, whereby an engineer would charge you about £30 to 'clean' your expensive Technics tape deck's heads when all he'd actually do is tweak a tiny screw to re-align the read head... (trust me, I know an audio engineer
)
The alignment issue should NOT be the first suspect, as the DVD lens, unlike the old tape heads, is capable of tracking and self-adjusting to a certain extent.
Sure, there could be a scratch or dirt on the lens, but the problems arising from this would manifest with other discs too.
The culprit is almost certainly the burn quality of the discs. DVD-Rs are coated with dyes, and the dye, bonding and general manufacturing process of the disc itself can lead to unreliable copies.
Plus, if a poor quality disc is burned at too fast a rate, the disc will be almost certainly unusable.
Even though the data is actually still ON the DVD, it is possible that due to a combination of the above mentioned problems, your DVD player cannot read the data and process it quickly enough to watch. Bear in mind that you are watching a movie at approx. 25 frames a second, that means your DVD player is having to basically read and display 25 pictures every second.
Whilst there IS error correction on DVDs (the DVD player has a 'buffer' whereby it reads slightly in advance to make sure that if an error DOES occur, there is enough buffered frames to ensure continuity), if the player has a hard time reading/decoding, the buffer gets empty, and because there is no real-time data to be displayed, you get a 'pause' or a jump.
Therefore, if your DVD drive is taking longer than expected to read the data due to read errors, the picture will not be updated fluidly—because your DVD player will 'best guess' the missing info in order to let you carry on watching your DVD. It's trying to maintain continuity.
On the other hand, when 'ripping' a DVD, your computer DVD drive isn't trying to display the info at real-time. It is only reading data and storing it to hard disc. Therefore, it can take as long as it likes to process it's error correction. Unlike watching the DVD 'live', there is no need for continuity, so a five or ten second gap while the drive and machine piece together the data is acceptible.
Once the data is safe on your hard drive, you can re-author it to good quality DVD and it will be fine.
It takes me back to when we used to back up work to the early SCSI CD writers. They burned at 1x, and even then, if the data from the HD wasn't being streamed fast enough you'd end up with coasters!
Because we were backing up non-replaceable computer data (design work, websites, images etc) it was crucial that we got a good quality burn. Basically, burning a 650Mb disc would take about an hour, and if you were obsessive (like we were) it would take about 30 mins to verify. Imagine that at 1hr 20 mins into the burn/verify cycle, you got a read error... I spent MANY late nights just backing up work to 2 CDs!!!
There have been, and always will be a huge gap in the quality of hardware and media. It is totally true that cheaper DVD players can be just as good as ones costing three, four or even five or more times the amount.
I have a Yamada 6600, cost me £35, and will play ANYTHING I put in it, (CD, MP3, VCD, DivX, .avi, .mpg, etc. etc.) and I cannot fault it at all. Conversely, I also have a Sony DVD player, 2 years old, which cost £200+... which will skip and jump on DVD-R and even pressed DVDs at the slightest sign of dust.
So, the moral of the tale is don't immediately jump to the conclusion that it's your PLAYER which is at fault, just because the discs play fine on another system. Take a look at the DVD play surface... if it's NOT pure silver (most DVD-R are purple), or you can clearly see concentric bands of data at different hues radiating from the centre of the disc (usually two distinctly different colours) then it's more likely you are holding a BURNED disc as opposed to a commercially pressed disc, and that a simple RIP/BURN to decent media will cure the problem.
