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Accessing a DVD using libdvdcss from normal command line programs

Posted: 26 Apr 2017 19:02
by keybounce
(I hope this is the right forum).

So in a simple sense, what I want to do is make a file by file decoded copy of a raw DVD as a folder on my hard drive.

Why? If I am trying to rip a copy of a DVD, the speed at which I can make a test run is limited by the I/O speed of the DVD generally. Being able to copy the DVD to disk first would allow me to go faster -- both because of the speed of the SSD, as well as the OS's file cache which is even faster.

More than that, some DVD's have special extras that don't translate to a movie -- things like interactive games, etc. These need the actual DVD files/etc intact.

But even with both libdvdcss and libdvdnav on my computer, something as simple as
cp -R /Volumes/DVD_NAME ~/Movies/DVD_NAME doesn't work.

Now, in some sense, this is "obvious" -- there is nothing in "cp" that knows to use libdvdcss, and that library doesn't force itself into every loaded program (egads, I'm surprised both at the large number of libraries that show up in an arbitrary program's dump, as well as that such a potential security hole even exists in the first place).

But if libdvdcss's job is to let a disk be used as a block device with no concerns about the encryption system, then shouldn't it be possible to mount a raw device through a virtual block interface using this, so that it would be accessable as decrypted files?

I have a strong lack-of-knowledge here, but my first thought would be a FUSE system that acts as the decrypting block device. Is this possible? Does it already exist?

Re: Accessing a DVD using libdvdcss from normal command line programs

Posted: 26 Apr 2017 19:12
by RĂ©mi Denis-Courmont
Block device decryption sounds more like a job for the Network Block Device driver than FUSE.