One hour of video equals 13 GB, right?

Question

Level 2

250 points

One hour of video equals 13 GB, right?

Howdy gang. I haven't been here for around six months. Been busy with website stuff. Now that that's done, I can get back to video work. Yeah! The forum looks a bit different, but it looks like you guys are still a super funny and really helpful group.

Here's my quick question. My boss wants me to put everything I've ever shot on tape into my computer. Now, I know the old saying, one hour of video equals 13 GB. But to be clear, and to be sure I don't buy a harddrive that ends up being too small, does that mean if I capture a one hour MiniDV tape it will take up 13 GB on my harddrive? Or is it 13 GB for an hour that's been exported as a QT movie?

I should know this. I'm embarrassed for not being sure. But I get kinda panicky and second-guess myself when it comes to asking the boss for new equipment.

So am I right in figuring that a 500 GB drive will hold footage from about 38 one-hour MiniDV tapes?

Thanks!

Dual 2.5, Mac OS X (10.3.6)

Posted on Nov 2, 2006 12:02 PM

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Answer 1

dMerc

Level 2

345 points

Nov 2, 2006 12:18 PM in response to Ann Apuladay

When I use a calculator I get DV/NTSC is 14GB to the hour. When it's captured it is a Quicktime so exporting would depend on the format.

I think 38 hours would be a little more than 500...like 502GB.

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Answer 2

Jim Cookman

Level 7

23,435 points

Nov 2, 2006 1:22 PM in response to Ann Apuladay

Hey stranger! first off an import of dv=an export of dv, and approximately 13 gigs per hour either way.

Secondly you do NOT want to fill up a drive more than 80%, as it begins to get really sluggish and may give you dropped frames. use 400 gigs MAX on a 500 gig drive. Some will say leave even more free space.

If all your future shooting will also be digitally immortalized, get one or two terrabytes worth of space.

(You know of course that this could also mean you're about to get fired.)

Ho ho.

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Answer 3

jbell

Level 1

25 points

Nov 2, 2006 1:24 PM in response to Ann Apuladay

1 hr of video captured at the "DV-NTSC" Easy setup will equal a bit over 12GBs. Figure 13GB to be safe.

So if you have 38 tapes, that should come out to about 494 GB.

Be aware though that if you buy a "500 GB" hard drive, you'll loose quite a bit of that. My LaCie 500 only has about 470 of "actual" storage.

I'd probably go with the next size up, a 650Gb, just to be safe. Or you could buy 2 smaller drives say 300Gb. It would probably be cheaper than buying one bigger one.

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Answer 4

Nov 2, 2006 1:29 PM in response to Jim Cookman

You know of course that this could also mean you're about to get fired

Isn't that why file and drive permissions were invented?

rh

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Answer 5

Ann Apuladay Author

Level 2

250 points

Nov 2, 2006 1:52 PM in response to jbell

As always, you guys have come through -- with the knowledge and the humor. I missed this place. I hope you all have been well.

Thank you!

Now I'm off to BHphotovideo.com. (They pay for product placement/name dropping don't they?)

Dual 2.5 Mac OS X (10.3.6)

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Answer 6

Nov 2, 2006 1:55 PM in response to jbell

jbell brings up a good point.

Drive manufacturers sell drives with space calculated in decimal, while the computer sees space calculated as binary.

To a drive manufacturer, a gigabyte is 1,000 megabytes. To a computer, a gigabyte is 1,024 megabytes. Therefore, when you buy a 500 GB drive (500,000 MB), it's actually only 488.2 GB to the computer (because 500 GB would be 512,000 MB).

And when an hour of DV is said to be 13 GB, that's 13 * 1,024 MB, not 13 * 1,000 MB.

If you go by the binary prefixes outlined in this wikipedia article (which have yet to gain traction), a computer's gigabyte should be called a gibibyte (GiB).
http://en.wikipedia.org/wiki/Gigabyte

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Answer 7

diffkid

Level 3

790 points

Nov 2, 2006 2:03 PM in response to Ann Apuladay

Here's the math (cause I'm dorky and like to show my work):

25 Mbs/sec
60 secs/minute
60 mins/hour

25 6060 = 90,000 Mbs

8 bits in a byte

90,000 / 8 = 11,250MBs or 11.25GBs per hour

38 hours/tapes

25 60*6038 = 3,420,000 Mbs

3,420,000 / 8 = 427,500 MBs or 427.5 GBs

Of course, actual storage space will vary, because of hard drive block size, file format, and all that technical stuff, etc. So its definately safe to assume 13GBs/hour.

I will also agree with everyone that you'd be cutting it close with a 500GB drive, so I'd split it up between two drives.

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Answer 8

Nov 2, 2006 2:10 PM in response to diffkid

Correcting for how computers see gigabytes (1 GB = 1,024 MB):

11,250 MB = 10.986 GB (11,250/1024)

427,500 MB = 417.48 GB (again, dividing by 1,024)

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Answer 9

Jim Cookman

Level 7

23,435 points

Nov 2, 2006 2:11 PM in response to Ann Apuladay

Try Macmall if you like the lacie drives. They've got the 500gb fw 800's for 260 or so. almost half of what I paid for mine...

I'm really liking g-raid these days though.

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