Friday, June 27, 2008

Why Avoid Archiving Video on DVD?

DVDs are great distribution media. They hold around 5GB of material, which is pretty good for most content, even compressed video. When I finish a video I might upload a lousy-resolution version to the web, but I'll probably burn a DVD or two for friends or family.

But know this about recordable DVD:

1) Video DVD's compress video using the MPEG-2 method, which throws out image data in order to make the files small. It is okay for a viewing copy of your videos, but since it's much less resolution than the video you shot, you probably don't want to store raw material this way. As a rule of thumb, you want to store/archive your videos in the highest, most unprocessed format you can. This means full resolution, uncompressed, unprocessed. DVDs are not this.

2) If you use the DVD simply as a data storage device, think of it as a CD that holds 5GB of data -- this represents about 25 minutes of Standard Definition video uncompressed DV, or 35 minutes of HD video, compressed to ACHD format. Like I said, this is good for finished cuts, but it isn't even a single tape's worth of raw video. If you have a lot of tapes, this isn't great.

3) Video DVDs must be prepared out of real-time, so getting the video into your computer then onto the DVD is a bit of a process and takes a little time.

4) Perhaps the most important drawback: Recordable DVDs have a relatively unstable recording substrate-- a layer on the disk that has a colored dye that works with the laser. These dyes fade over time, and consequently discs can become unreadable as the disc ages, usually far more quickly than either hard disks or MiniDV tapes lose reliability. Since DVDs have a shorter lifespan, they aren't ideal archive formats.

Put all these together, and I'd say that for everyone but the most casual hobbiest, skip recordable DVDs for long-term storage of your video.

4 comments:

Frankie said...

What do you remcomend for saving DVDs that I have created and if a friend or family wants another copy. How can I recreate this without the initial work.

Rubin said...

A little depends on what software you used to create it in the first place. When you make a DVD the software does a big MPEG2 compression before beginning to record; when you burn that first DVD it usually asks if you want to record a second (or more) since it has already done the long/hard part, and can more quickly roll off additional dupes. But when you finish, it discards those working files.

If you still have the original iDVD project (for instance), you can re-run it easily to make more copies; it still takes some time, but no more "work" for you. If you don't have the original project file, and only have a finished DVD, it's trickier.

You could certainly rip the DVD (as it has no copy protection), but that doesn't get you the menus and architecture... just the video. On a Mac much of the internal files are often hard to isolate and duplicate; on a PC it can be easier to find the DVD folders and simply copy them to your hard disk, remove the DVD and insert a recordable blank, and copy them to it. I think this could work, but it's really something i have experience with. I'll ask some DVD experts i know and see if i can get you a better answer. It's a very good question.

More soon...

Special Deal said...

If you still have the original iDVD project (for instance), you can re-run it easily to make more copies; it still takes some time, but no more "work" for you. If you don't have the original project file, and only have a finished DVD, it's trickier.

Brad said...

Hi Michael,
I just borrowed ldvb from the library yesterday after ordering a new cam corder with internal flash drive. I really enjoyed learning so much about video making so quickly. I knew that I didn't know much about making sketches from scenes and the art of video making. Well it is apparent that I didn't know how much of the technical side I do not know.
Before my inexperience leads to a costly result can I ask if I can safely transfer video to dvd's or do I need to save the original flash memory? Now I want to say your practical approach and accessible writing style made learning enjoyable. Turning what might be dry and technical subjects for novices into helpful and useful tips is a rare gift.
Thank you.
Brad True
Brad True