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< Part 18 | Part 19(a) | Introduction | Part 20 >

The Videomaker's Journey: part nineteen (b)
Burning DVDs and Archiving.

Use the links in the text to move between sections.

This second part of chapter 19 deals with archiving - preserving our movies in various forms for future viewing and future re-editing. The first part of this chapter deals with authoring and burning DVDs - see Part 19(a) .

CONTENT

Foreword

If "archiving" suggests storing things for centuries - think again. In our terms it means keeping movies so that they can be seen in ten or twenty years time. Amateur and prosumer video storage media are not ideal for long-term use.

Our best bet is to make digital copies onto top-quality tape cassettes (new ones from any of the well-known brands). Store those in air-tight Tupperware-type boxes, so that a narrow edge of the cassettes is at the bottom. Keep the boxes somewhere with a very steady temperature and not near a powerful magnetic current. Once a year spool the tape all the way from one end to the other. Every five years copy the tapes to brand new top-quality ones and preserve those.

In fact the speed of change in technology is such that within five years there will probably be a new form of storage. Whenever you re-equip with a new format, copy the movies to it.  If you do not keep them on the latest format there is a good chance you will not have a working player ten years down the line. (Anyone got a Betamax machine or a 17.5mm cine projector lying around?)
At present tape is the most reliable medium we have for video storage. It is susceptible to magnetic damage - not so much from outside equipment - though don't keep tapes on a loudspeaker or cathode-ray type television set - as from "print through" where a strong signal partly transfers itself from one coil of the tape to another. A greater risk is chemical change in the base material over time which loosens its grip on the magnetic layer and makes the tape dry and brittle.

DVDs are at present a convenient storage method because they hold large quantities of data in a digital format (making them easy to copy without loss of quality) and are cheap. The life of home-burned DVDs is uncertain as yet, but a new copy can easily be made each year.

Stand-alone computer hard drives which plug in to a USB or firewire port can be a useful way of storing files. They are, however, very easily damaged by small bumps. Remember that a hard drive is a moving mechanism and will wear out. The average drive life  of a hard drive is about 7 years.

Disperse your archives - you may want to make more than one archive copy of your work and store it in a different house or a different town to guard against the risk of a major fire or flood ... at last  you have a good use for your relatives!

- Dave Watterson

ARCHIVING AND DVDs

Even in their DVD authoring section, Apple Mac books advise that to archive, you should transfer the video back to MiniDV tape, where it will last 10 to 15 years, and also archive it onto a spare external hard drive as a backup. MiniDV tape is tough and very reliable.

I do that ... but I also like making archive DVDs.

PROBLEMS AND ADVANTAGES OF  DVDs

Against

DVDs that we burn in our computers and stand-alone DVD recorders do not last very long. If they are used a lot they will probably only survive 5 years. When stored carefully they might last 10 years. We really don't know.

The bottom surface of these DVDs is coated with a dye - the laser in your computer or DVD recorder burns tiny holes in the layer of dye. This surface is extremely unstable. The holes are easily damaged - they distort and may become distorted by moisture and heat. Professionally made DVDs, which are foil layers pressed from a glass master, are supposed to last 100 years. But I read there can be durability problems with some of them.

For

If the disc does not fail, the video images on  a DVD won't deteriorate. Using top-quality discs and a backup system avoids a lot of problems.

Good copies of your movies can be made - without loss of quality - by using firewire cables (also known as iLink or IEEE1394) to connect camcorder or deck to computer or stand-alone DVD recorder.  

DVDs can be produced at various qualities - a balance between how much playing time the disc will have and how much the pictures are compressed. We always use the highest quality setting, which will record 60 minutes of video on a 4.7 Gb DVD.

It is very convenient and quick to select a DVD and load it to a player or an editing computer.

Usually, after every camera shoot, I transfer the video from the video camera to a DVD in my pioneer DVD recorder - before I do anything else with it. This is a backup in case the video tape becomes damaged, though it is now many years since I have had such problems.

ARCHIVING

I have 70 hours of video, archived to MiniDV tape. There are 25 hours of family video and 35 hours of travel video, which consist mostly of overseas travel. Before archiving them I had an editing session that removed all the rubbish. I also added titles at regular intervals showing dates, locations and peoples' names on all this material. It is all too easy to forget such details over the years.

Re-editing

Some of the video is also archived on a spare external hard drive - this is extremely useful - it is quick and easy to access, when I need to re-edit it. All the video will be filed on spare external hard drives in the near future.

[ Most amateur videos are less than 18 minutes long. You can store that length of video as AVI or MOV files on a DVD. This is a simple copy of the file and not the "rendered" (compressed) version produced by a DVD authoring program. Some computers allow you to use a recordable DVD just like any other storage system. In other computers you need to use a general CD/DVD burning program in its "data copy" mode. Such files can be read back from DVD into your editing computer very quickly if you want to do a re-edit later. Such a disc is a backup and will not play on most stand-alone domestic DVD players which only play movies that are in a different type of file and within a standard set of folders. Of course this type of DVD is subject to the same  physical problems as all other home-burned DVDs.]

Once is not enough

When you archive - you should create more than one archived copy as backup - either make a second MiniDV tape - or archive to a spare external hard drive. You may choose to keep one copy purely for preservation and the other as a "working" version for occasional use.

[ Run 10 seconds of a cleaning tape through the camcorder or deck you will be recording onto. Cleaning tapes seem expensive but you only run them for a few seconds at a time ... besides, your movies are worth it. As of mid 2008 typical MiniDV cleaning tapes cost between £5 and £9. They are specially recommended for cleaning between using one brand of tape and another, since each brand has slightly different tape coatings which might not react well together.]

Step 1 Transfer one or more edited movies to MiniDV tape. These tapes will be kept as the backup "preservation copy" archive. By exporting the edited movies you are not storing the unused video shots and the editing baggage, just the pure finished product.

Note some MiniDV tapes are better than others - ask around for advice. Always use well-known brands and new tapes - not the ones you have been working on for weeks! The best have a reliable life of 10 years - and have been known to last at least 15 years. The MiniDV tape picture is slightly better than the DVD picture because the latter has to be re-compressed which introduces a tiny loss of quality.

To keep track of where everything is, I number each MiniDV tape and make a document file, which lists all the movies against the MiniDV tape numbers.

Step 2 Import the movie from the MiniDV tape to a "movie" file (i.e. usually in the AVI format) on an external hard drive. Keep it there as the main "working" archive. It requires around 13 Gbs of disc space per hour of video. This video is very easy to copy onto a movie file on the main hard drive when I want to re-edit.

When loading movies to the external hard drive, and there is more than one movie on the Mini DV tape - I stop and re-start the loading at the end of each movie. This way each movie becomes a separate video clip on the Movie file, which makes it easy to transfer the required movie to the main hard drive.

Step 3 Where you have made the final edit and the video will not be edited again - import the movie from the MiniDV tape onto your computer as a movie file, then make a read only "DVD disc image" file. Keep this on an external hard drive as a backup. It requires about 6.5 Gb per hour of video.

DVD copies can easily be made from that, but you cannot easily extract the movie file for re-editing from these DVDs.

At this moment, when making a “DVD Disc Image” in the iMac Computer - I have to immediately burn a DVD so as to check that the “DVD Disc Image” is OK. It is not possible to preview a “DVD Disc Image File”. According to the Instruction Manual we are supposed to be able to do this. I have advised Apple of this problem - hopefully they will fix their software.

Professional format electromagnetic tapes with video recordings on them have been known to last up to 30 years - if properly stored as an archive and not normally used. Refer to Part 20 Transferring old VHS and S-VHS video to DVD.

Carefully store your DVDs. Keep them in a cool, dry place - out of the light. Handle them with care - hold them by the edges.


APPENDIX: OPTIONS FOR SAVING YOUR MOVIE/S

This is based on my own experience with Mac computers, but the information may help you to understand other DVD authoring software. The hard drive volumes I quote are based on my experience to date - these may change slightly once I start doing a lot of archiving in the computer.

I have 70 hours of video recorded to DVD, it is all also archived to MiniDV tape - the following notes are based on my experience using iMac software. If you only have a few hours of video to deal with then you won't use a large volume of disc space - you won't need to compress any of your video when you archive it on an external hard drive.

A special feature of iMovie6 HD is that all video loaded into it is converted to HD (High Definition) size. This means the computer doubles up the number of picture lines and does some tidying up. The image is not true High Definition but could be inserted in an HD movie. (It would, however, not look so good as video shot on an HD camera.) But I output to SD (Standard Definition) anyway.
(a) Video straight from the camera requires 12.7 Gb of storage space on the hard drive for each hour of movie.
(b) An edited movie, including the unused video shots and the editing baggage can use up to 30 Gbs per hour of space on the hard drive.
(c) Transferring /exporting edited movies back to MiniDV tape - removes the unused video clips and other baggage associated with the editing process. When the movie is transferred from the MiniDV tape back to a movie computer file - I will refer to it as "movie" file (baggage removed) - it only needs 13.2 Gbs to store an hour of video.
(d) If I want to re-edit the video in the future, it can be transferred to an external hard drive - this will be kept as the Backup Archive.

The Apple iDVD system offers a number of save options:

(e) The "DVD Project" file
Normally this is only created and kept for as long as it takes to prepare the final DVD. It requires 1 to 3 Gbs of storage.

The project file holds the information needed to set up the movies to burn the DVD - including details of the theme/s (menu/s) you have created. It is an empty shell - it does not contain the actual movie/s.  It is linked to the "movie" files, which are filed elsewhere. You must not delete the movie files. If you delete the movie files - the "DVD project" won't work - you cannot burn a DVD.

The DVDs that are burned  from the DVD Project File will be "read and write" - which is the normal Apple setting. [In PC terms you can read and copy those files.]  

The "movie" files (baggage removed), plus the "DVD Project" file - will use a total volume of about 18Gbs per hour . This is OK for a small amount of video. Archiving both of them on a spare external hard drive is possible but it is hard to see any practical reason for doing so other than  perhaps clearing your main disc drive for another project which you wish to do before returning to this one.

(f) The “DVD Disc Image” File.

It is best to think of a "disc image" as being like a "zip" or "stuffit" file. It packs up all the files and folders needed to make the kind of DVD which can be used on stand-alone domestic DVD-players.  Someone said it is like a DVD without the plastic!

To let the computer use it, you must first fool the computer into thinking it has an extra disc drive and that the file is a disc in that imaginary drive. The Apple operating system does this automatically when you try to open the DVD Disc Image file. If you look with the Finder tool, you will see that it appears as a new drive.  Other computers do not do this automatically and will require some third-party software such as Nero to fool the computer in this way.

The advantage of making such a file is that you fool the computer into loading it and can then play it with your normal DVD viewing software just as if you had actually burned (written/recorded) a real disc. That allows you to check everything before you actually risk burning onto any blank discs.

Originally such disc images were intended as a safe means of transferring groups of folders and files without accidentally missing any. Later it was used to send sets of files over the internet. It was never intended as a file for direct use. It always has to be unpacked. Its normal use is to unpack the files and folders it contains onto a blank DVD and thus to create a playable DVD.

A “DVD Disc Image” on one of my Projects got the Storage Space down to 6.6 Gbs per hour of video. Just remember that you cannot re-edit it and so it is of no use if you want to keep a copy of the movie for later revision.  (You could use it to reconstitute a normal playable DVD and extract the movie files from that for later editing, but the process degrades the pictures a little.) The format does not include unwanted Baggage. It does let you make any number of DVD copies in your computer so as to replace damaged DVDs.

Using the Disc Utility in Mac OSX to burn the DVD copies:-
  • Do not Select File yet.
  • Go to  Applications > Utilities > Disc Utility
  • Select the DVD Disc Image File, which is on the Disc Utility Menu.
  • Click on the Burn button. A message drops down - “Waiting for Disc to be inserted” - so ... insert a blank disc.
  • Click on the confirmation Burn button which is on that drop-down message.
  • The DVD will automatically Eject when the Burning is complete.
  • I have the Mac OSX 10.4 Tiger System which has the 06 software. In my case there is a problem in that the iMac's built-in DVD Player will not open and play the DVD Disc Image. It is supposed to do this so that you can check it.  I have reported this problem to Apple on the “Send Feedback” Link, hopefully they will fix it. Ask the Question “Testing a DVD you created” on “Help”. In the meantime I have to burn a DVD to check it.
  • It took 9 minutes to burn a 13 minute DVD.
(g) The "Archived DVD project".

This stores both the "encoded files" (aka "rendered files") - which are the versions of your movie/s that have been compressed into the DVD format - and the original movies as well as all the menus and so on. It  saves everything and so uses a huge quantity of storage space on the hard drive. You would  need a total volume of about 25 to 35 Gb per hour of movie or more on the hard drive. I do not recommend it.


< Part 18 | Part 19(a) | Introduction | Part 20 >

© copyright Arthur Bullock, 2008


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