On Fri, Aug 24, 2018 at 12:08:06PM +1000, Trent W. Buck via luv-talk wrote:
1. that specific DVD disc has <4.7GiB of actual raw bytes on it, i.e. if you did
cp /dev/sr0 my-dvd.udf # or
dd if=/dev/sr0 of=my-dvd.udf
the resulting file would be normal DVD-size.
I assume so, I haven't used optical media for almost 10 years :-)
2. inside the ordinary UDF filesystem might be (say)
versions of the movie, which are 95% identical, but just have 5%
different scenes --- e.g. the original theatrical version, the
director's cut (5% extra content) and the pre-watershed TV
broadcast version (5% less content - no sexy bits).
So when Rohan ripped the DVD into some conventional format, he ended up with (say)
which "adds up" to more than the DVD can logically hold.
That's how I understand it.
3. this is similar to hard links (or btrfs/ZFS shared
removing them due to incautious copying. Example:
Probably an apt analogy, since the VOB files in the directory structure
are able to reference the same VOBs (or subsets thereof) on disc, albeit
it gets more complicated than that, i.e. the DVD-Video format includes
it's own machine-language and VM.