Tapeless Workflow – Disk Image Archive Method

It’s just about safe to say tape is dead. Lets face it, tape had it’s benefits. It was relatively cheap and we always had a back up of our footage. It was a pain to capture everything in realtime though! However, even though digital media is fast and convenient for ingestion, we are left with some difficulties when it comes to back up and archival. They key it to formulate and implement a back up and archival plan that you will use. You can also use this handy Disk image technique to easily create Disk image files that preserve original media structure and format to use in your archival scheme.

The Long Term
Something that is very easy to over look is long term preservation, archival and access. You may not realize it today, but you many need footage 20 or even 30 years from now. There are three major issues to contend with though.

Video formats change like wild fire these days. 20 or 30 years down the road we don’t know what resolution or format of video we will be using or able to access. In the days of tape, you needed 2 things, a tape deck that could play back the tape format, and some device to read the single that it out put. In general video signals are standardized, so even if the tape is old, the video signal can still be read fairly easily. With digital video, we are at the mercy of the codec. While it’s generally safe to assume popular codecs will be readily available in the future, we have to also consider many other factors. Companies may drop support for codecs, the medium that you have your footage stored on may not be able to be read by future computers or devices. Also there is the consideration that digital files can be come damaged or corrupted.

Today the general workflow is to transcode media for the the native camera format, to an editing based codec like ProRes. So the question becomes, which format do I use for archival? There are 2 ways to look at this. When we used tape, we had a similar workflow. Video was recorded onto a tape in the format that the camera used, such as BetaCAM SP. You then took this tape and digitized it to a codec that you edited with. Not all that different for how we work without tape. We, now log and transfer to a format that we edit with. For long term archival of your footage I suggest you work the same way you would with tape, preserve the original format using the methods described in the rest of this article. I did say there were too ways to look at this though. The second is, for archiving your edited project. With tape, it was easy to take media offline and re-digitize, although it was time consuming and of course things could go wrong. With a tapeless digital work flow, you can work the same way, however it’s a bit antiquated. I suggest you save the media and the project separately in the format you worked in. Moving forward this does present some issues with compatibility, however, it provides an easier short term access solution. And chances are you can always convert a project in the future daily easily, but we will not know until we get there.

So, to summarize, I suggest you save your footage as you would tape, and also archive your project and media as well. Depending on the client, and the project there are several issue as to whom is responsible for this, who will pay for the storage and archival. These are conversations I suggest that you discuss with your clients. I also suggest that any editor provide these services. A client will likely happily pay down the road when they find out you can save there butt.

Long Term Archival Medium
I think one of the biggest challenges today is how do we back up and archive all of our media. First of video, especially professional HD video files are huge, and storage is not cheap! Also storage technology changes very quickly and a hard drive that you used today maybe nearly impossible to use 5 even 10 years down the road. Currently there are not many good solutions on the market. If you have the money, you can easily do this properly, but the expense is outrageous for must of us. And given todays budgets it’s not cost effective in the least.

There are 3 major things to consider; Cost, Space or Capacity and Longevity. They key to a successful archival plan it to organize and follow through. You need to use a method that works for you, and one that you’ll keep up with and maintain. There are lots of different ways you can approach this, so take in the following suggestions and pick the method that works best for you. Then stick with it.

Hard drives are cheap and really easy to use. This is going to be the options that most people like for archival. But there are many things to consider. First spinning hard drives fail, so use RAID protection or have multiple back ups. Also consider longevity, and that you’ll likely have to use new HDD’s every 2-3 years. So in the long run drives aren’t as cheap as the may seem.

Optical media. I don’t really consider this a practical solution these days, space is limited, but it’s dirt cheap with a decent shelf life.

LTO, or other tape based media. This is an expensive investment, however it has the best shelf life, and the overall cost is not all that bad in the long term. Also LTO tape backup is reliable and insurable. This is a very slow method or back up and archival, but with a good plan much of this can be done overnight without to much hassle.

The cloud is another option, but it’s not likely ready for the terabytes of data required for video. The cost is likely to high currently, and transfer times are not efficient.

Sort Term and Ease of Use
What do you do in the short term? What’s the best way to save and archive your footage? These are the common questions we have to ask when dealing with gapless media. The fact of the matter is each of us organize and work in different ways. The key is to use a system or method that works for the way you work.

Using Disk Utility to create a Disk Image of media cards.
One of the easiest ways to quickly back up your media cards is to create a disk image using disk utility. There are several advantages to working this way. First, it’s a built in tool, so you don’t have to download or buy any special software. Second, it preserves the integrity and directory structure of the media card, saving you hassle down the road. It also allows you to mount multiple cards simultaneously, something that usually isn’t possible with a single card reader. You can some verification of the file when you create and mount a disk image. Finally, you end up with a single DMG file that you can name as you please for each card. This is nice because by naming the DMG file you don’t change the integrity of the media at all.

So how does this work? What is a Disk Image or DMG file? When you record your video to media weather it be a Compact Flash card, SD card or SXS card, you essentially are using a volume or disk. The camera will format the cards and use a directory structure that it understands. Depending not the video format and so on, there is a directory structure that is used to identify clips and metadata. If you were to just copy the files off of the card to your hard drive, you would generally preserve the overall integrity of the directory structure, however, instead of an actual volume you now have a folder with the contents of the card. While the difference is minimal, there are some fundamental and technical differences. When you create a Disk Image, you are making a virtual volume of the contents of the card. When the Disk Image is mounted it will be identical to having the media card inserted into your computer. The obvious advantage is for software that looks for media cards instead of folders, but there are many more benefits as well.

How do you create a Disk Image? It’s easy to do this. First, I suggest you plan out a few things. How do you want to organize your media, and where do you want to store it. One of the advantages of using this Disk Image technique is that the files are easy to move, so you don’t have to pick a long term archival home just yet.

Mount the media using your card reader or the camera. It will show up as a volume.

Launch Disk Utility, which can be found in the Applications > Utilities Folder.

In Disk Utility you will see a column on the left that list all of the volumes connected to you computer. It is a tree structure and you will see a listing for the actual media, then indented below it the formatted volume. For example your hard drive is likely there, first listed as the Capacity and Manufacture (this will very from machine to machine). Look for you media and select the formatted volume, which may be called “untitled”. This name will vary depending on what camera you are using.

Once you have the formatted volume selected choose “New Image” from the tool bar. You can also find this option in the file menu under File > New > Disk Image From “Volume Name”. Make sure you select the option with the volumes name as there are other options that will give you different results.

You will be presented with a dialog box giving you several options. First select the location you would like to save the Disk Image file (.img). This goes back to the plan about where you want to store you footage. I do suggest you use an external drive with RAID protection, however, it’s fine to save to you desktop for immediate convince as long and you move the file to a safe location eventually. You can name the file whatever you like, again I suggest that you use a naming scheme that makes sense for you, and will help you easily identify the media later. This name will not effect anything on the original or new media that you are creating. It’s essentially just the name of the file that you will be making. Once you mount that file it will be identical to the media that is on the card. In the next set of options you have to select the image format and Encryption. I suggest you leave these as the default settings. For image format it should be “compressed” and encryption is none. For the image format, compressed will make the image file the size of only the media that is on your card. For example, lets say your card is 32GBs. Instead of making a 32GB file when you only used 4GB, the compressed Disk Image will create a 4GB representing the 32GB media. If you have sensitive footage that you would like to password protect you can select one of the encryption options, and you’ll have to supply a password to use the file in the future. Make sure you remember it if you use this option. Once you’ve set the location, name, and these options click save and the Disk Image will be created.

Creating the Disk Image will take some time, not only is it coping the contents of the media to your destination drive, but it is also doing some verification along the way. Once it’s done you will end up with a .dmg file. This is the Disk Image file. It contains the contents of your media. Eject the card you just created the Disk Image from, and double click on the disk image file. You will see that it will mount identically to the media card you just created it from. You are now free you eject that volume, and you can always remount it by double clicking on the .dmg file.

Now you can see how easy it is to move and archive these .dmg file, and they will act just as your media card did originally. So even if you use Final Cut’s Log and Transfer, or any other method to copy or transcode the original media, you still have a preserved Disk Image of the original card contents, much like the original tape back in there days when tape was used.