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Devices

CDs, DVDs, and BDs are common types of removable media. Unlike other types of removable media (such as flash drives or external hard drives), they are normally used read-only and many of them require special burn programs. I.e. they are not mounted for writing like "normal" filesystems. CD, DVD, and BD are optical discs, so we can use that term to refer to them collectively.

Your PC will offer device files to access your optical disc(s). Such devices are typically called drives, players, or readers, and are generally detected as /dev/sr*, where * is a number starting at 0. (Thus your first drive will be /dev/sr0, second /dev/sr1, etc.) Symlinks such as /dev/cdrom, /dev/cdrw, /dev/dvd, or /dev/dvdrw (pointing to /dev/sr0) may also be created depending on your OS version and the detected capabilities of your device.

The sequence of device file numbers may change with each reboot. The directory /dev/disk/by-id contains symbolic links with names which show persistent name parts. Like:

/dev/disk/by-id/ata-HL-DT-ST_DVDRAM_GH24NSC0_K8AF33A3528
/dev/disk/by-id/usb-Optiarc_BD_RW_BD-5300S_306663601043-0:0

The name parts "HL-DT-ST_DVDRAM_GH24NSC0_K8AF33A3528" and "Optiarc_BD_RW_BD-5300S_306663601043" are supposed to persist even if you change the way the drives are attached to your computer.

Optical Media Formats

You will normally encounter two types of readable optical media and one type that is writable:

CD-DA

CD-DA contains audio tracks in a low level format that can only be read by music CD players or by specialized software like icedax or readom from wodim. Writing is done by burn programs in audio mode.

CD-ROM

CD-ROM contains data which are readble by normal means as from normal data files or block devices. This format is only one of several CD sector formats. DVD and BD media always appear as CD-ROM. Their video or audio content is wrapped in read-only filesystems. Writing is done by burn programs in data mode.

Read-Write Media

DVD+RW, DVD-RAM, and BD-RE media may also be written as normal block devices. Formatted CD-RW and formatted DVD-RW may be used that way by help of device files /dev/pktcdvd* and program pktsetup out of udftools. Their performance with random access writing is quite poor, though. For larger amounts of data, you are better off with burn programs, which are needed for CD-R, DVD-R, DVD+R, and BD-R, anyway.

Read-write media may be used like CD-ROM media as long as only reading is desired.

Detecting and Mounting

To detect the device files of your CD/DVD/BD drives, use one of these commands

cdrskin --devices
xorriso -devices

from the Debian packages with the same names.

To check which special file /dev/cdrom is a symlink to (i.e. /dev/sr0, /dev/hdc or /dev/scd0), type:

ls -al /dev/cdrom*

Mounting is often done automatically to a directory underneath /media/ when a readable medium gets inserted into a drive. You should wait with accessing it, until the drive LED stops blinking.

If no automounting is enabled, then you may mount a data CD, DVD, or BD by

sudo mount /dev/sr0 /mnt/iso

Possibly you have to create directories /mnt and/or /mnt/iso before you see success with this command.

Watching Video DVDs

For unprotected DVDs, watching them is often as simple as installing VLC which has the function built-in and depends on the necessary libraries to watch and interact with DVDs. The same goes for others such as MPlayer, mpv, and kaffeine

However, many DVDs use the CSS (Content Scrambling System) as a form of DRM to encrypt the content of Video DVDs. To play such discs, a special library is required to decode them, libdvdcss.

Due to the legal limbo of libdvdcss in some particular jurisdictions, some distributions including Debian do not distribute libdvdcss directly.

On Debian 9/Stretch and newer versions, you can install the libdvd-pkg package which automates the process of downloading and setting up the necessary library. This only requires you to have the "contrib" component enabled in your SourcesList file.

Setting the region

Some DVD players require the region to be set before they are able to play encrypted DVDs. This has to be done manually with regionset. The man-pages provide help in choosing the proper country-code.

Ripping

To almost quote Wikipedia, ripping is the process of copying input audio or video content (typically from an optical disc) and outputting to a "normal" storage filesystems. Ripping is typically more difficult than simple file copying (as when copying files from a flash drive or external hard drive) in that

This involves at least 3 separate problems (discussed in more detail here):

  1. reading the optical disc (which this page is largely about)
  2. writing to the desired output format
  3. gathering or authoring metadata

FAQ

4GB per File limitation in ISO 9660

Optical media are often filled with an ISO 9660 aka ECMA-119 filesystem. Data files of size 4 GiB or larger are allowed by the specification of ECMA-119 Level of Interchange 3 (mkisofs option -iso-level 3).

Nevertheless, Solaris and the BSDs are unable to properly represent such files when the filesystem is mounted. On such systems one may extract large files from ISO 9660 filesystems by help of program osirrox out of the source tarball of GNU xorriso.

Converting DVD

See also


CategoryHardware | CategorySound | CategoryVideo | CategoryStorage


ToDo: refactor, merge other CD/DVD related pages