I’ve read that DVDs “usually” use the UDF file system and that DVDs “contain a file system, called UDF, which is an extension of the ISO 9660.”
I don’t know if that means that DVDs have an inherent ability to utilize UDF that CDs lack, if "proper "DVD burns should be done in UDF or something else I haven’t thought of.
My burning software, Nero Burning Rom from Nero 6 Ultra ed, does allow the choice of “DVD UDF” or “DVD UDF/ISO” in the Compilation Properties Window/Wizard/Whatever, but “DVD ISO” is the default. [I can’t imagine how “DVD UDF/ISO” would work unless it allows the other settings to determine which file system is used]
The UDF file system seems to me to be radically different rather than “an extension” of the ISO9660 [+Joliet+etc] file system and I’ve usually seen them classified as 2 different file systems. I would expect it to matter kind of a lot which I chose to get the best results when burning a lot of data multisession DVDs.
UDF is always explained in terms of packet writing and the ability to decrease mutisession overhead so you can write a greater number of smaller sessions and to allow CDRWs/DVDRWs to be mounted as “drives”. I know there is more to UDF than that - OS independent w/ a “redesigned” directory structure - but nothing I know about UDF or about DVDs explains why I’d use it for a burn once or multisession data DVD and I’d think ISO9660 w/ DAO would be used to burn movies to DVD.
My understanding of a CD multisession burn is that it records in TAO, altho it might burn several tracks per session. DVDs have Titles rather than Tracks. I thought they were functionally sort of equivalent and a DVD multisession did its own version of TAO. Packet writing doesn’t seem to offer any advantage here, but maybe the “redesigned directory structure” does. Does anyone know if choosing UDF when doing a multisession DVD lets you fit more on the disc or increases the reliability of the burn?
I know [or I’ve read] that DVDs have significant differences compared to CDs [and even DVD+R to DVD-R], but other than the smaller pits, narrower tracks and different laser I haven’t found an explanation of those differences or any information on whether some software handles those differences better than others. Maybe Nero’s default should be “DVD UDF”
The option to ‘finalize the disc’ is greyed out for DVD’s in Nero’s Compilation Properties Window/Wizard/Whatever. I haven’t had any problem accessing files on my multisession DVDs, but I want to be prepared for when my current computer equipment hits its planned obsolescence and I’m concerned that I can’t finalize a DVD. The days of backing up to CD are long gone.
If anyone can provide some links to articles or discussions about optimal software utilization of DVD specs I’d appreciate it.