Whether you are preserving home videos or protecting an investment by safe guarding your movie collection from scratches, having a digital backup is invaluable. As a film student, all of my shorts are on DVD. Having moved several times and switched between computers I have lost master footage and project files for most of my films. All that is left of my college work is on a few DVDs. I recently consolidated my work onto a large one terabyte drive (a 1,000 gigabyte external hard-drive) for long term storage and duplications.
$ dd if=/dev/disk1 of=file_name.iso bs=2048
Above is the command we will be using to create an iso image file of a DVD to playback or burn. If you have knowledge of command line usage, you needn’t read on. However, if this looks foreign to you please continue the short tutorial; there is potential for damage if used incorrectly. Read through once before following along.
$ = denotes a new command line (don’t actually type $)
‘ ‘ = Type the words/characters within the quotes, but not the quotation mark itself.
[ENTER] = Physically press the ENTER/RETURN key on your keyboard
Step 1: Insert DVD and Open a new Terminal
Place the DVD into the DVD drive. If it starts playing, press stop and QUIT the player.
Go to: Applications > Utilities > Terminal (Click on ‘Terminal’) A program window will open.
Step 2: Navigate
Within the Terminal, navigate to the folder wherein the backup will be stored ( ie. An external drive or media folder). This can be done with the ‘cd’ command. If you know the folder pathway, type:
$ ‘cd /path/to/the/folder’
Or drag and drop the folder into the Terminal window using your mouse (after typing ‘cd’). This should create the path for you. In my case I have:
$ ‘cd /home/mat/Videos’
Step 3: Look up and Unmount
$ ‘drutil status’
This command will give you a readout of the various drives installed on the computer. Look for the DVD drive in the readout. Note the path for that drive (ex. /dev/disk1).
Now we need to unmount the drive. This will allow us to make a copy of the dvd without the computer thinking it’s already being used by another program.
$ ‘diskutil unmountDisk /dev/disk1’ —- Remember, your drive may be slightly different.
With this command-line, we have called upon a program (diskutil) gave it a command (umountDisk) and specified the disk (/dev/disk1) to which we needed it applied. If done correctly, the DVD icon on your desktop will disappear.
Step 4: Copy it!
$ ‘dd if=/dev/disk1 of=file_name.iso bs=2048’
Replacing ‘file_name’ with whatever name you want to call it. The ‘bs=2048’ ensures the .iso will be read by the ‘dd’ command as a DVD. The process will take around 30+ minutes, depending on your system. Let it run. There won’t be a progress bar. So long as the cursor is on a blank line, it’s not done.
Upon completion immediately mount the DVD drive. Forgetting to do this will create frustration when trying to remove the DVD.
$ ‘diskutil mountDisk /dev/disk1’
The DVD icon will reappear on the desktop. Eject as usual. You now have a digital backup from which you can burn a duplicate DVD.
Note: An error may occur early in the process if you are acting as the root user. Simply type ‘sudo su’ [ENTER] You’ll be prompted for your administrative password (the one you’ve previously assigned).
If backing up encrypted DVDs (your movie collection), you will not be able to playback on a standard DVD player due to the encryption keys. This is not a problem for me because I watch everything through a computer hooked to my big screen. To playback on a computer, you will need a player that circumvents the encryption key such as VLC player (it’s free). Yes, there are ripping tools you can download/purchase that disable the encryption, which are beyond the scope of this article.
If you opt not to burn the iso to a DVD, understand the format. Playing an iso file is not the same as playing a video file (.mpeg, .avi, .mov, etc.) It is recognized by your computer as a drive containing two folders ‘video’ and ‘audio’. To play an iso you need to mount it. This is usually done by double clicking the icon or typing ‘hdiutil mount /file/path/file_name.iso’ in the terminal. If all else fails, Google is your best friend on this topic.
Keep in mind this is a 1 to 1 transfer. Every bit of the cd/dvd will be copied straight to your computer without compression. Ensure that you have enough free disk space. To provide you with some frame of reference, one uncompressed feature length movie in standard definition is about 7.5 – 8 gigs.