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audio preservation project

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I am taking 90,000 minutes of analog audio recordings (1000 90 minutes tapes) and converting them to a digital format to be preserved for the future. We will be converting each tape to CD but also want to keep a master copy on digital tape. I have an 80/160 gig tape drive that I plan to use to backup the tapes onto but I have a question about restorability in the future. Each tape is about 1 gig so I need to backup 1 terrabyte I estimate 13 taps will do it.

Here is the question currently I am using Dantz Retrospect 6.0 for my backup needs but if I were to save using that program now and 10 years from now Dantz is out of business will I be able to restore the tape with someone elses software? Is there an industry standard for tape formats? I am sure other people have run across this issue and I would like to know what there/your solutions/experiences have been?

I am also open to other suggestions on how to save the data in an archival format. I have entertained the idea of hard drives since the tape format may not be supported in 10 years but I am sure that I can read an NTFS drive in ten years from now :-) Though I doubt data archival reliability of hard drives and data reliability is as critical as ability to restore many years down the road.

BTW The tape drive I am using is an Exabyte VXA-2 Firewire drive.

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Don't use magnetic media of any kind for archival purposes....far too fragile (and pretty expensive).

Use DVD-R Disks (ones rates as "archival quality" are rated for 100 years). Store it using one of the lossless standards, there'll be DVD drives long after a particular tape standard leaves us.

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The zip format is great for compressing uncompressed bmps, perhaps it will work as well for uncompressed audio. (instead of using a proprietary backup format)

If you do use a codec or other compressor, be sure to include the neccesary files in your backup to be able to read that format of file when restoring.

I agree that DVD might be the best way to go.. in 10 years who knows if you'll be able to find a P-ATA (or even S-ATA) hard drive controller... and if you keep a HDD controller with your backups who knows if computers in 10 years will even use PCI slots... same deal with tapes, the current interfaces for your tape drive may be dead by then. CDs and DVDs have show great backwards compatibility and it's likely they will continue to do so in the future.

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The zip format is great for compressing uncompressed bmps, perhaps it will work as well for uncompressed audio. (instead of using a proprietary backup format)

If you do use a codec or other compressor, be sure to include the neccesary files in your backup to be able to read that format of file when restoring.

I agree that DVD might be the best way to go.. in 10 years who knows if you'll be able to find a P-ATA (or even S-ATA) hard drive controller... and if you keep a HDD controller with your backups who knows if computers in 10 years will even use PCI slots...  same deal with tapes, the current interfaces for your tape drive may be dead by then. CDs and DVDs have show great backwards compatibility and it's likely they will continue to do so in the future.

sound advice :) (no pun intended) any recommended places to get "archival quality" dvd's? Can you get archival quality dvd+r as well?

Are there such things as archival quality cd's?

I most likely won't use a lossless codec for the same reasons I will use dvd's instead of a tape drive. Who knows if the lossless codec will work on a computer in 10 years. Though I would be fairly confident it would work in 10 years I would guarantee that WAV files will work in any machine in 10 years. I don't mind the extra work of twice as many DVD's given the greater confidence I can have knowing they are easily restorable without needing my expertise as the people I am doing this for are not very pc literate.

So at 4.5 gigs per dvd that is 4.5 tapes per dvd that is 200 to 250 dvd's Alot but not an overwhelming amount. 2 large cd folders.

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So at 4.5 gigs per dvd that is 4.5 tapes per dvd that is 200 to 250 dvd's  Alot but not an overwhelming amount.  2 large cd folders.

sure beats 1,000 tapes.

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By the way, i think it would be a good idea to have a couple copies. How important is it that the audio be preserved perfectly? perhaps you can additionally convert the audio to mp3 and store it on say 100CDs.

And in all honesty it may not make a whole lot of sense to prepare for 10 years down the road. Once you have tha data stored digitally in a RAW format (as uncompressed wavs are) you can always transport from one medium to another forever. Planning ahead for 2-5 years may be more realistic.

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Are DVDs still stuck at 4.5GB? I thought the standard was eventually supposed to go up to 15GB (multi-layering and focusing the laser to a specific layer or something...)

Other thought : keep the original analog tapes too. Magnetic media may be fragile, but I have a Grundig tape reel from 1959 that still plays.

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For archiving, use the FLAC compressed file format. It is open source, lossless, and will compress your files far greater than zip. Monkeys is an alternative (is it GNU yet?) as is the SHN (shorten) compression format.

I do not recommend tape for archiving data, as the maintanance is really-really high. An optical solution (DVD) is highly recommended. If you absolutely need to stream to tape, use TAR.

This reminds me... I have a bunch of 2" reels in a vault in Vermont that I should pick up sometime (from back when I wanted to be a rock star).

Thank you for your time,

Frank Russo

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So at 4.5 gigs per dvd that is 4.5 tapes per dvd that is 200 to 250 dvd's  Alot but not an overwhelming amount.  2 large cd folders.

sure beats 1,000 tapes.

Yeah but it doesn't beat 12 tape 80 gig cartridges in terms of space taken up in a safety deposit box ;)

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Yeah but it doesn't beat 12 tape 80 gig cartridges in terms of space taken up in a safety deposit box  ;)

What is the envoromental spec guarantee of a safety deposit box?

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Are DVDs still stuck at 4.5GB? 

...

Other thought : keep the original analog tapes too.  Magnetic media may be fragile, but I have a Grundig tape reel from 1959 that still plays.

AFAIK all consumer grade burnable DVDs are still stuck at 4.5GB...

1959 Eh... Many of the tapes in this project are from the 1970's and some are barely audible due to the degradation (I think it is caused by electron drift). It isn't our hope to do any audio restoration on them now but to later do it on an as needed basis. Who wants to spend 4 man hours per hour of audio and do audio cleanup on 1500 hours of audio (about 250 straight days of work)? (note: I am not looking for an answer to that question ;) ) I guess reel-to-reel are less fragile than a standard 90 minute cassette, learn something new every day.

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  Who wants to spend 4 man hours per hour of audio and do audio cleanup on 1500 hours of audio (about 250 straight days of work)? (note: I am not looking for an answer to that question  ;) )  I guess reel-to-reel are less fragile than a standard 90 minute cassette, learn something new every day.

Audio cleanup is easy (well, sort of)....

The quickest method is to simply play the tape at 1/4th speed as it is recorded into a wave file. Then speed up the wav file by 400%.

Thank you for your time,

Frank Russo

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The quickest method is to simply play the tape at 1/4th speed as it is recorded into a wave file.  Then speed up the wav file by 400%.

Sorry, It might be because it's late here....but can you explain the logic of how this does anything besides slowdown/speed up the audio?

I might be thinking too digital....

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I agree with blakerwry. Plan for 5 years preservation with the expectation that in 2007 you'll be moving all of this data to the media format du jour around that time.

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The quickest method is to simply play the tape at 1/4th speed as it is recorded into a wave file.  Then speed up the wav file by 400%.

Sorry, It might be because it's late here....but can you explain the logic of how this does anything besides slowdown/speed up the audio?

I might be thinking too digital....

I think the idea is that you're caputring four times as many samples per second, greatly reducing your odds of a dropout. You'd have the option of time-compressing the audio, essentially discarding three out of every four samples, using some sort of interpolation algorithm (which is basically what sampe rate converters do), or playing it back as is -- audio captured at quarter speed with a 44.1KHz sampling rate should play back at the proper speed using a 176.4KHz sampling rate, which many audio cards can already handle, to speak nothing of what will be available a few years down the road.

FYI, a properly stored analog tape will play back up to half a century in the future (we know this because even poorly-maintained old tapes are being found and restored all the time). A digital tape is far more likely to show its age, even after a few years of storage, beacause if you lose a sample, you lose a sample and that's it. Analog degrades far more gracefully than digital.

Oh, and I'll believe all those "100 year" archival CD claims in 100 years when a) they find a working CD player to test that theory and B) manage to retrieve usefull data from one of my Mitsui discs.

Piyono

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I agree with blakerwry.  Plan for 5 years preservation with the expectation that in 2007 you'll be moving all of this data to the media format du jour around that time.

Agreed.

Piyono

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FYI, a properly stored analog tape will play back up to half a century in the future (we know this because even poorly-maintained old tapes are being found and restored all the time). A digital tape is far more likely to show its age, even after a few years of storage, beacause if you lose a sample, you lose a sample and that's it. Analog degrades far more gracefully than digital.

Oh, and I'll believe all those "100 year" archival CD claims in 100 years when a) they find a working CD player to test that theory and B) manage to retrieve usefull data from one of my Mitsui discs.

This probly goes in the you already know this department but it caused me to think.

Analog does degrade more gracefully for a single standalone tape. But because analog does not allow perfect copies and digital does this doesn't hold up in a multiple copy scenario. If I make 10 copies of tape A call them A1..A10 and ten copies of the digital version D1..D10. The analog tapes will ALL degrade eqiuvalently plus the copying will cause a degradation. There is no way to stop the degradation of the analog tapes, eventually they will be unsusable (be it 10,20 or 200 years). In the digital world one can get clever with a tool like PAR (smartPar or fsRaid are my favorites) or simply taking the ten files and choosing the most correct bytes (i.e. using the bits/bytes that have the most agreement). So over time all analog copies will degrade "gracefully" but the digital with proper care should not.

I agree with you about trusting those archival claims ;)

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Consider this - if 10 years ago you had wanted to store archival digital media, you would have been forced to use a host of options that are currently unpopular. That includes DOS-based compression programs, 8" or 5 1/4" diskettes, etc. So I would probably:

1) Use uncompressed media files, such as .WAV. Too much hassel to try and get an antiquated media codec to work under the Linux 7.5.2 kernel or Windoz 2015 - unless you include the source code as straight C/C++ and expect to have to re-implment it in the future. I would include hard copies of the source code if going that route...I would certainly stay AWAY from any proprietary solutions.

2) Archive with the most up-to-date media standard available today, as that is likely to be the least out of date. In my mind, that would be DVD, although CDs have SUCH market penetration that their is a good chance that there will still be players available in some form.

3) Mothball 1-2 complete PC systems (including CPU, DVD, monitor, software, etc.). These systems should be stored in a pristine, unpowered state, with just enough burn-in time to get them stable. Ideally, I would hermetically seal them to protect against moisture, or place them in a controlled environment.

4) Consider leaving archives of the digital files on a mothballed RAID 1 array of harddrives, connected to the mothballed PCs. Powered-down 10 year old drives STILL work in most cases, and a RAID 1 array gives you protection against a single drive failure. Alternately, I would consider RAID 5+1, as it offers even better protection (up to two drives?). If pursing this strategy, consider a thin, grounded lead shield to guard against stray magnetic fields.

In the end, only you know what the anticipated economic or cultural value of these recordings is, and how much you can spend to protect them...

Future Shock

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2) Archive with the most up-to-date media standard available today, as that is likely to be the least out of date.  In my mind, that would be DVD, although CDs have SUCH market penetration that their is a good chance that there will still be players available in some form.

My only comment its that I wouldn't use the latest media (e.g. bluegay) because it might turn out to be a betamax :blink:

I think DVDs are the way to go. It might be worth the extra hasstle to do it in .WAV format and just mothball a set-top DVD player as well...

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The quickest method is to simply play the tape at 1/4th speed as it is recorded into a wave file.  Then speed up the wav file by 400%.

Sorry, It might be because it's late here....but can you explain the logic of how this does anything besides slowdown/speed up the audio?

I might be thinking too digital....

I think the idea is that you're caputring four times as many samples per second, greatly reducing your odds of a dropout. You'd have the option of time-compressing the audio, essentially discarding three out of every four samples, using some sort of interpolation algorithm (which is basically what sampe rate converters do), or playing it back as is -- audio captured at quarter speed with a 44.1KHz sampling rate should play back at the proper speed using a 176.4KHz sampling rate, which many audio cards can already handle, to speak nothing of what will be available a few years down the road.

This is half correct.....

The number 1 contributer to analog playback quality is head position, which we will not discuss here.

The number 2 contributer is tape speed. The more ips, the better the quality. slowing down the tape on playback essentially gives the head "more time" to read what's on the tape, and kinda does the same as origionally recording at a higher ips (not quite). This is why low speed tape dubs sound better than high speed dubs. The heads have more time to put the info to tape, and you can saturate things a little more.

Another important factor here (which goes back to your half) is that you use a digital audio tool that does interpolated phich-speed changing. One way to test is to speed up a piece of audio and listen for phase changes on the high end (tell-tale sign that it is not interpolating correctly). Sound Forge 4 did this correctly, as did Cooledit 2K. Nero's audio editor does not.

Give it a try some time. To play back the tape slowly, I recommend that you get a cheapie Tascam portaflex or some other 4-track tape player. I can play back at 50% speed, and use DBX while boosting the signal a little bit before it hits the A/D convertor (make sure the analog signal is regging at least -4db on your PC).

Thank you for your time,

Frank Russo

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