DV tapes

[ToiletDuck]

Ok i work for ABC as an editor and i work with the DV format. I believe the tapes are 25mbps. Now I have a question. If the tapes are digital. If the tapes have timecodes on them. Which they are and do. Then could I use them as a storage backup? Because if so that would equal about 99,000mb on a 66 minute tape. And if you could put 99 gigs on one tape that has a time code, could you store files on it and then access them off the tape? I mean didn't the old government computers use to run all their data strait off the tape?
Duck

[bb]

Yes, in principle you could use these tapes as a storage backup. But you have to get your files to the tape somehow (and back to the PC, of course). This is just what streamers do, although they use different tape formats.

I remember that I've read somewhere that a guy managed to store files on a DV tape using his camcorder, but I don't find it anymore (and have no proof that it works either).

bb

[ToiletDuck]

that's what I was thinking. If i have a $25-30 tape that can hold 99 gigs of info. It would be cool to put all my divx onto them. Have an archive or divx tapes. You think you would be able to watch the divx right off the tape though?

[bb]

Probably not. You download DV in realtime, but for DivX files you'd get the data faster than it would play, so I guess you'd have to transfer it to the disk first (if this is possible at all).

bb

[DDogg]

http://www.dvstreamer.com/

Actually, it is more like 10 gigs.

[AudioVideoMaster]

What about re-using, the "data" tapes this program makes, for regular camcorder video use.

I.e.: Like you don't want to use the tape to store data anymore... you now want to use the tape to record regular video from the camcorder.

Anyone tried this?

[DDogg]

Or it might be the other way around - a good use for used tapes to have additional usefullness as data storage tapes. A lot of folks will not reuse them more than once or twice if the shoot/content is important.

[ToiletDuck]

our DV tapes at work are 25mpbs and 1hr 6 minutes. 25mbps x 60 sec= 1500mb or 1.5 gigs. 1.5x66=99,000megs or 99 gigs. I bet you could pull it right off if you managed to get it to right. It would just buffer out i'd think. And if not you can still transfer it at 25mbps so it wouldn't take long at all if your harddrive could write that fast.

[ToiletDuck]

would be cool then to take it to work and then change the medium again to a regular VHS tape lol. That would take some freaking doing there hehe.

[DDogg]

Yep, I see what you are saying. Most of the time on this forum when somebody says "DV tape" they are speaking of MiniDV, or at least that is how I "hear" it.

[ToiletDuck]

Yea I figured that :) A lot of the home cams use the mini tapes that have about 20mbps or something like that and a short shoot time. But still I wonder. Has anyone used a camcorder or something similar to store files. I would like to try it. And even if I can't stream off it. Wouln't take long at all to pull a gig file. About a minute if you have a good harddrive setup.

[ToiletDuck]

Ooops I just saw your link.. Good Job!

[ToiletDuck]

I've been looking on ebay and DV decks cost an arm and a leg. Any idea on some cheap device that can write onto DV tapes?

[lemon]

> our DV tapes at work are 25mpbs and 1hr 6 minutes.

25mbps x 60 sec = 1500 megabits = 187.5 megabytes
187.5 x 66 = 12375 megs ~ 12 gigs.

1 Megabyte = 8 megabits.

[Owen]

Good job Lemon.
I was waiting for someone to point that out.
Your maths is the same as mine.
It's 12Gig not 99Gig.
Same as MiniDV.

[ToiletDuck]

hmmmm. maybe they are mbps instead of MBps. However mini dv's are still 20mbps not 25 or 50 that the pro tapes are capable of handling.

[lemon]

I'm sorry ToiletDuck, but miniDV and DV are exactly the same format, they only change in the size of the tapes.
They are both 25mbps, exactly like DVPro or DVCam, which are simple variarions of the same standard.
DV and miniDV are internally exact.
There's a DV50 format, with double the data rate, but it's called DV50 or DVPro50, and it can be stored in different sized tapes too.
The tape doesn't define the format, it's only a container. If you record something in DV format (in a DV tape, miniDV tape or a hard disk) you can transfer it to any of the other DV containers simply copying it. It will always be exactly the same data. And it will always be 25 mbps (3.125 mBps).

[FredThompson]

http://www.carr-engineering.com/dvio.htm
http://members.tripod.com/~liaor/
http://dvbackup.sourceforge.net/

DVTransfer is dead but I have a copy.

[ToiletDuck]

Our tapes that we use at the station can do either 25 or 50 mbps and the mini dv tapes that i have seen are 20 mbps

[lemon]

The tapes can't do 25 or 50. They are only a container.
Your equipment perhaps can do 50. Then it's DV50. It's completely independent of the tapes.
MiniDV is 25mbps. The tapes aren't 25, they are only tapes. The equipment is always 25 mbps.
There's no DV equipment that does 20. DV is always 25. And it doesn't depend on the container.

If your tapes can store 66min at 50mbps, then you can store just double the data, 26 Gigs instead of 13 gigs per tape.
But if they store 66min of DV, they can store only 33min of DV50.

[ToiletDuck]

the tapes can only do what they are designed to do. you can't just cram a ton of info on them if your hardware can. they can only hold so much info just like any other median.

[lemon]

That's just what I have said before ;-)