Doom9
9th December 2002, 14:07
c't had a big article on recordable DVDs in the last issue. They've performed a pretty thorough media test, the results of which can be seen in this thread: http://forum.doom9.org/showthread.php?s=&threadid=39575. The only comment I can add is that c't mentioned to take the results with a grain of salt as production can be changed over to another plant which could yield discs of very different quality.
Currently, most people buy DVD-R because the blanks are currently cheaper (though when it comes to really good media the difference is really small). That may, however, be subject to change: If you look at the recordable surface of a DVD-R you'll see a small ring close to the center that looks different. This is the area where normally you'd have the CSS codec on a pressed DVD-5. This ring is there to prevent 1:1 copies of DVD-5s (that's why you have to rip 'em first and burn 'em later, during the ripping process the CSS stuff is removed so it can be burned onto a DVD-R blank). Here's where it gets interesting: This area has to be burned!!! on each disc that is being manufactured. Theoretically this area could be stamped when the disc is created (which would obviously be much quicker) but some members of the DVD forum (can you say MPAA members;) want the manual way because this way each blank can have its own ID number. DVD+R on the other hand has the copy protection in the firmware (so theoretically it could even be hacked).
Therefore DVD+R production is cheaper and the copy protection is potentially weaker.
DVD+R is also addressing sectors more accurately so they need less "help" via the physical structure of the disc (and don't need help from the software to prevent buffer underruns). DVD+R/W also supports multisession writing without problems (on DVD-RW a disc has to be finalized before it can be read on another drive), packet writing and allows you to overwrite part of an already written +RW disc (mostly interesting for standalone recorders). And then there's the issue with the minimal disc size of 1 GB on DVD-Rs that DVD+R does not have. Admittedly, some of these issues have been resolved in the meantime (if you use special software (like the latest release of InstantCD/DVD), standard software like Nero for instance does not support this stuff (yet?)).
Also interesting is that most DVD+R blanks are manufactured by the same company (Ricoh). This is obviously not very good for prices. Once more manufacturers are beginning to produce DVD+R discs that could have quite an impact on disc prices.
Something else rather interesting: Some of you might remember my rand on manufacturer codes. At least for the 2x DVD-R blanks there are no specs - hence I guess the manufacturer IDs have some merit. There's a standard for 4x DVD-Rs and 2x DVD-RWs though.
Last but not least c't has also discovered some manufacturer ID irregularities. Some discs do not contain an ID, and on others there's a wrong ID (Princo illegally uses a TDK tag - these discs cannot even be burned on the new Sony burner).
Currently, most people buy DVD-R because the blanks are currently cheaper (though when it comes to really good media the difference is really small). That may, however, be subject to change: If you look at the recordable surface of a DVD-R you'll see a small ring close to the center that looks different. This is the area where normally you'd have the CSS codec on a pressed DVD-5. This ring is there to prevent 1:1 copies of DVD-5s (that's why you have to rip 'em first and burn 'em later, during the ripping process the CSS stuff is removed so it can be burned onto a DVD-R blank). Here's where it gets interesting: This area has to be burned!!! on each disc that is being manufactured. Theoretically this area could be stamped when the disc is created (which would obviously be much quicker) but some members of the DVD forum (can you say MPAA members;) want the manual way because this way each blank can have its own ID number. DVD+R on the other hand has the copy protection in the firmware (so theoretically it could even be hacked).
Therefore DVD+R production is cheaper and the copy protection is potentially weaker.
DVD+R is also addressing sectors more accurately so they need less "help" via the physical structure of the disc (and don't need help from the software to prevent buffer underruns). DVD+R/W also supports multisession writing without problems (on DVD-RW a disc has to be finalized before it can be read on another drive), packet writing and allows you to overwrite part of an already written +RW disc (mostly interesting for standalone recorders). And then there's the issue with the minimal disc size of 1 GB on DVD-Rs that DVD+R does not have. Admittedly, some of these issues have been resolved in the meantime (if you use special software (like the latest release of InstantCD/DVD), standard software like Nero for instance does not support this stuff (yet?)).
Also interesting is that most DVD+R blanks are manufactured by the same company (Ricoh). This is obviously not very good for prices. Once more manufacturers are beginning to produce DVD+R discs that could have quite an impact on disc prices.
Something else rather interesting: Some of you might remember my rand on manufacturer codes. At least for the 2x DVD-R blanks there are no specs - hence I guess the manufacturer IDs have some merit. There's a standard for 4x DVD-Rs and 2x DVD-RWs though.
Last but not least c't has also discovered some manufacturer ID irregularities. Some discs do not contain an ID, and on others there's a wrong ID (Princo illegally uses a TDK tag - these discs cannot even be burned on the new Sony burner).