How to back-up/copy DVDs

This is a basic primer to back-up or copy your DVDs. More specific information can be found at a number of ever-changing websites; at the present time, the best of which is

Feel free to add, but keep in mind the specifics are better answered at the websites that specialize in the topic.

Thanks to Koma for agreeing to archive it.

We'll start with a quick lesson on how DVD works, because you'll need to know this stuff to make the correct decisions. If you're already familiar with the format, you can skip to my third post for examples of the tools you'll need.

The first distinction you'll need to make is the difference between dual-layer & single-layer. The mechanics of DVD work just like a CD, except that everything's smaller (so there's more data,) AND the laser has the ability to focus through the first layer of data to a second one, doubling the effective capacity.

The problem with dual-layer (for you) is that there are presently no consumer dual-layer burners or blank media. When you make your copies, then, you have to make a choice - either you have to split the data across two DVDs, or you have to reauthor the DVD to have less data. Both options are problematic.

The other distinction you need to make is that DVD is not a real-time format. Unlike analog tape (for example, VHS,) which records a steady stream of similar data at the same qualitative level across the length of tape, DVD has to COMPRESS its video information at an unspecified strength to make it fit easily.

It works by comparing consecutive frames to see what similarities it can repeat rather than record. This process causes visible artifacts; the more you compress, the more visible the artifacts become. Many DVD authorers employ specialists that analyze each scene of the product to decide the optimum compression rates. (Caveat: there are real-time DVD recorders, but they make qualitative decisions that are usually counter to the optimum ones.)

It's important to understand this because you'll instinctually want to recompress all your dual-layer DVDs to single-layer ones, BUT this will make all of them look terrible by comparison.

A better solution is to split the media across two discs, which retains the optimum quality of the media, but reduces the utility of the design.

Another option is to use a program to strip out the features you aren't going to use, such as menus & bonus features. Often the parts that you want will fit on a single-layer disc by themselves. however, you'll also need to reauthor your new disc so it works in the DVD format.

One last thing you have to know is that most commercial DVDs are interlaced with copy protection to prevent you from doing what you want. You'll need a decrypting program to get around this.

(Part 2: Nuts & Bolts, & Part 3: Tools, follow.)


Nuts & Bolts:

There are a few different file formats you'll see:

1. The DVD format requires a folder called VIDEO_TS to contain the data it will use to play the video. Inside this folder, you'll usually see a bunch of files with extensions like .IFO, .ISO, & .BUF. The first .IFO file is the one that the player will read first, which contains the pointers to the data it needs to either play the first track or put up a menu. The rest of the files contain the data. You can expect to see 3 or 4 files much larger than the rest on any DVD containing a film; that will be the film data, with the rest usually being the bonus features & menus.

2. There is also an AUDIO_TS folder, but outside of DVD-AUDIO discs, you probably won't ever have to worry about this. It's usually empty.

3. An image file (.IMG) is the format most burning utilities expect to see their data in. You will probably be running into issues will you will want to convert a VIDEO_TS folder into a disc image, & vis versa.

4. If you are going to go deep into authoring, you are going to be dealing with compressed video files (.MPG,) audio files (.AC3, .PCM, etc.) & Photoshop files for your menus, etc. This primer isn't going to deal with any of that.

So, the authoring workflow looks like this:

Raw media (.MPG, .AC3, etc.) to authored DVD media (VIDEO_TS) to burnable disc image (.IMG).

(Tools to follow.)



So what do you need to get started?

One of the most prevalent answers is DVD X-Copy, which is a commercial all-purpose solution.

Here are some current freeware options. Make sure to check for tutorials to maximize your options (& not burn any coasters!):

For decryption & burning: DVD Decrypter

(Note: It only burns images. If you are decrypting a single-layer DVD, you can do this simply by decrypting in image mode & burning it; otherwise, you'll probably want to use file mode for further processing.)

For splitting across two DVDs: DVD Fab

(Note: This expects a dual-layer VIDEO_TS folder with only one big movie on it. Anything else, like a bonus features disc or episodic TV series, & DVD Fab will crash.

This program puts all the menus & bonus features on the first disc, & fills the rest of it with as much of the movie as will fit, so you retain most of the functionality. Then it puts what's left of the movie on the second disc, so you have to change discs somewhere in the middle.)

For splitting episodic dual-layer DVDs, etc.:
Also, for recompressing media:

DVD Shrink

(Note: This gets dangerously close to authoring, so pay attention to what you're doing.)

For converting VIDEO_TS folders to disc images:


For Mac: Freeware tools are much harder to come by. For decryption, os ex. But you still have to burn with the commercial burning software that you probably received with your burner, e.g. Toast. There are unix tools to handle this, too, but they're fairly complex. Sorry there's not more out there.

Good luck!



Yeah, that's where it is. :)


go to

look around on all the forums - they will link you step by step guides, complete with screen shots.

Your "how to" says nothing about burning to dvd. Making a back-up doesnt do any good with you transfering the img to a disk. There are specific parameters that need to be set when burning or you ewnd up with coasters.

after dawn has burning guides for nero and veritas software -

I've never used, or had the need to use imgtools as you suggest. after I have my TS_Video folder, I use my burner software (I prefer veritas), burn the disk, and I'm good to go.