Why use optical disc for the backup copy? Have you considered a hardware media player connected to your TV, with internal or USB disks or network access to remote disks?

I don't know whether any media players play native DV AVI or not, but if not then SD MPEG2 is the way to go and with the same quality as a DVD, but tidier and smaller physical size if you have a lot of material.

Some media players accept ISO images of optical discs (DVD and sometimes Blu-ray) so you can have menus if you want.

Interesting ideas, PeterDuke. One reason I haven't been thinking along these lines is that I have the notion that a physical optical discs would be more future proof somehow, and that it would be something I could pass along to my son after I'm gone. But this thinking could be in error.

I guess I'm looking for the simplest, lowest-tech solution short of the actual tapes (which will be preserved), that would maintain the quality.

If I do go the route of DVDs as MusicVid suggested, then what rate would any of you suggest to effectively get the same quality as DV?

And doesn't blu-ray support the same SD mpeg2 format, albeit on a larger capacity disc?

James

A VHS tape typically holds 2 hours (SP T-120).
2 hours per DVD equals about 4Mbs or a little better.
4Mbs is more than enough bitrate to retain VHS quality.
Do what you will, but I still suggest you keep it simple.

There is no advantage to putting VHS on BluRay. It is not higher quality. It is not less expensive. You can't play it in a DVD player. It is much more sensitive to damage and UV. So why?

"Putting DV on Blu-ray involves upscaling, and the quality path from VHS->DV->Blu-ray will not be a happy one."

Upscaling is not necessary to create a Blu-ray project or store the material on Blu-ray media. You can prepare the media as if you were planning to write it to DVD using the MainConcept DVD templates. DVD Architect allows you to use SD format MPEG-2 media as your source when you start a project. You could put a lot of SD material on a 25 GB Blu-ray. It will be way cool for the six months the media lasts.
I agree with all the other comments about why you might do it some other way, but it is technically possible to store SD material on Blu-ray.

Since MPEG2 is based largely on encoding the difference between frames, the encoding quality at a given bit rate is particularly affected by video noise and motion. VHS tends to be quite noisy and it will require a higher bit rate to encode properly than would a very clean video. A noisy VHS video of a car race would require all the bit rate you could throw at it. The notion that a lower bitrate can be used because VHS is lower quality is somewhat of a fallacy.

The maximum bit rate for DVD is 9.8 Mbps which is the total of video and audio combined. Blu-ray has a maximum bit rate of around 40 Mbps. Disregarding the issue of Blu-ray disc longevity, you could encode your VHS video in SD at a high bit rate, like 15 or 20Mbps, and author the Blu-ray and it will look better than any DVD could. The higher bit rate means you would be able to put less time on the Blu-ray but the quality will be much higher. Of course, it will also require a Blu-ray player to view the disc.

One more thing to consider is that DV video uses 4:1:1 color sampling and MPEG2 uses 4:2:0, so after converting DV to MPEG2, you end up with 4:1:0 which means that only 12.5% of your original color information will have survived the conversion. This has always been true of DV to DVD conversions, so if you've never noticed it by now, you probably won't.

If you're worried about lifespan, I would suggest keeping the original DV files and store them to hard drives and maybe also Blu-ray data discs. Hard drives are really cheap these days. Digital data isn't considered "safe" unless copies exist in two physically separate places. Even then, there is no guarantee that your great-great grandchildren can read and decode the video in the future. This is where paper and film have it all over digital media.

"This is where paper and film have it all over digital media."

That's why I liked working with punched paper tape: you can see the bits.

A colleague from work once actually took a tape home and transcoded the ASCII code into English after we no longer had paper tape readers,

Thanks all for the comments. As I suspected, it is not a simple question with simple answers.
I'm hearing that BD discs will not have the life expectancy of DVD. Sounds reasonable given the higher capacity. So my question is can anyone point me to an authoritative source on DVD media life expectancy? There are various flavors of +/-/rw and all that plus different brands and formulations.

And to John Cline's point about color subsampling differences, does anyone know of a good converter that does color upsampling when going from DV to MPEG-2? Does that even make sense to worry about?

And yeah, there is no permanent anymore. Not that there ever was, but in this digital age it's getting more complicated to perpetuate the illusion...
James

"can anyone point me to an authoritative source on DVD media life expectancy?"

Probably not.

Media formulation is changing all the time, although DVDs are probably in the "milk the cow for all you can get" stage of development. Inovations are more likely to be to cut costs rather than improve longevity.

Some brands are better than others, but the brand you read on the packet is not necessarily the manufacturer. Even if you know the manufacturer (which can be read with appropriate software) that doesn't help if the manufacturer has off-loaded poorer grade or a special run for someone else.

There are so-called "archival" type DVDs with a gold layer which we hope are better than others.

The method of storage is also important. Store on end in cases that don't squeeze the hole, in a cool, dark, low humidity environment.

On the subject of archival DVDs, I found this which seems helpful:
http://adterrasperaspera.com/blog/2006/10/30/how-to-choose-cddvd-archival-media

Other opinions welcome.

James

As a general rule, Blu-ray players do a better job of uprezzing SD video than any software you might use to do the uprezzing. Unfortunately most of the uprezzing magic of these players only works on progressive video though. Still, I've yet to see software improve on what is built into most Blu-ray players. The only reason I uprez is when I want to put some SD video into an HD project.

The quoted article recommends Taiyo Yuden (now JVC) DVDs. This brand together with Verbatim are popular choices.

I have had DVD-R discs packaged as Verbatim but actually made by CMC Magnetics Corp. (A wag once said that CMC stands for "Coaster Manufactuing Company".) Verbatim is normally made by Mitsubishi Chemical Company.

After burning a DVD I always check the PI and PO (PIF) errors using Kprobe2. These are the checksum errors before error correction. I am surprised that the article made no mention of them. A bit of fluff or a finger print shows up as higher soft errors in the vicinity of the contamination, but not necessarily a fatal hard error.

The theory is that discs with lower errors have more tolerance to aging than the others, but I have never seen any proof of that.

Taiyo Yuden and Mitsubishi (Verbatim) typically have lower PI/PO errors than say Ritek or CMC, but it is not always the case. I have occasionally had TY discs with errors higher than I normally accept, so I discarded them and burnt again.

It is not feasible to burn say a 1-2 hour movie to a DVD and watch it the whole time with match sticks holding your eyes open to look for defects. Even if there is no glitch today there is no guarantee that there will not be a glitch tomorrow. So PI/PO tests are the only practicable test you can do that I know of.

Disc errors are a function not only of the disc media but also the reader. Some readers are better than others and probably work better with some brands than others too.

I don't think there is a reliable test comparable to PI/PO for DVD that you can perform on BD, unfortunately.

as an aside.....

a friend of ours is head of nuclear medicine at a major hospital in sydney.... they were told by admin to investigate media storage for their HUGE inventory of visual as well as text based case files. so, having approached EVERY major player (ibm, xerox, hp, etc.,) and been offered every digital possibility under the sun they chose the one format that has been proven to be totally future proof - microfiche.

as another aside, similar in a way---
I have about an hour's worth of regular 8mm Kodachrome 25 film shot by my dad in the 50s and 60s, of my family of origin. A few years ago I had it transferred right, by a lab in LA. Cleaned, liquid gate immersion to fill in the scratches, Rank Cintel flying spot scanner.
The scenes that were shot with enough light, which fortunately are most of them, are simply stunning... the colors are deep, vivid, and luscious. The film has held up for more than 50 yrs, and there is more information in each frame than I ever saw as a kid watching it projected. I'm so glad I have it. Actually, I'm just just now finishing that anthology project with Vegas to pass along to my sibs. Dad didn't have a tripod, so Deshaker has been my friend lately. Fun stuff.
James

On the otherhand, I was involved in transferring some 8mm film to digital a few years back. The oldest was about 25 years at the time and had developed a distinctly purple cast that I couldn't fix (the yellow had faded away). So don't expect all film to last 50 years.