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NeoMac · Jan 17, 2002, 09:24 AM

Does anyone know the exact amount of DV footage one can fit per 1GB of storage space?

I've heard widely varying numbers, between 4 -5 minutes. Does anyone know the exact amount? Does it include audio? Any factors that cause it to vary widely?

I'm trying to plan ahead. In the near future, I'm going to edit on my Mac using iMovie, but burn on some elses SuperDrive. I need to know what capacity drive I would need to transport 90 minutes of DV. I'd hate to buy a drive and find out it's too small and I would rather not buy more than I need either.

Tnx in advance.

[ 01-17-2002: Message edited by: NeoMac ]

scottiB · Jan 17, 2002, 11:05 AM

Five minutes is a shade over 1GB (I can't remember exactly), and, yes, that includes audio. A 20GB drive can handle 90 minutes, roughly.

SirCastor · Jan 17, 2002, 11:24 AM

DV usually comes in a hair over 5 minutes per gigabyte, but you have to remember (as in all compression schemes) the data is going to change the ultimate size.

This is especially important to remember with DVDs where variable compression shows up. When you have a shot which contains a large amount of the same color or same frame, the compression algorithim accounts for that by spending less time doing stuff there. It saves time and space.. So ultimately you might have a shot of a blue sky for 30 seconds (I dunno why) in which case the compression is not very complex because nothing changes.. so ultimately that may only take a third the amount of space as a shot would with lots of activity and color

Hope that makes sense.

NeoMac · Jan 17, 2002, 11:58 AM

The external drive I intend to purchase for this task will only be used to hold and transport the DV data. I'll then take it to a buddy who will be getting a G4. His system will do the compression since I only have a G3.

So, you are saying, a 20GB drive should be adequate to hold 90 minutes or (likely) less of edited (iMovie2) DV footage? If so, then that is what I will buy. Does it matter if it is 5400rpm or 7200rpm (for transfer, not capture, I mean)

I'd like to keep the edited footage. I presume, long term storage is better done by recording the DV data back to a MiniDV?

Jansar · Jan 17, 2002, 12:18 PM

The rpm's only refer to transfer speed, and technically, I'm not quite sure what I personally use, but I use a Cube, and it seems to work fine. I import videos with my digital camcorder, and it seems like the movies five minutes long are quite a bit less than a GB, however I checked again and found that it's true. I only have a 30 GB HD, and I've kept a large amount of data on my drive, but that's because I don't store a whole lot on my computer. It really depends on the usage.

opallaser · Jan 17, 2002, 02:21 PM

Yes it's about 5mins per gig. You must also remember that you need space for your render files.

I would suggest getting a 7200rpm drive simply because you will have fewer problems than with a 5400 rpm (which will work)

Moderator · Jan 18, 2002, 09:05 AM

but...wouldn't 5 minutes of DV footage from a three chip camera result in a bigger file than 5 minutes of footage from a 1 chip camera?

If a high quality still is a larger file because there is more information depicted then it would stand to reason that high quality video is the same.

If that's true than there is no one answer..it would have to depend on the camera and CCD.

jcarr · Jan 18, 2002, 10:23 AM

Originally posted by Moderator:
<STRONG>but...wouldn't 5 minutes of DV footage from a three chip camera result in a bigger file than 5 minutes of footage from a 1 chip camera?</STRONG>

Yes and no. The DV codec is a compressed format. While the uncompressed info from three CCDs is larger than from one CCD, after the hardware encoder in the camera is done with the data, it's down to the standard DV codec data rate. Otherwise you'd only get about 20min of recording on a 60min MiniDV tape.

BTW - A 60min MiniDV tape represents about 13GB of data.

scottiB · Jan 18, 2002, 11:35 AM

iMovie2 has an export selection for iDVD. If you want, you can export them ahead of time and drop the finished .movs into the iDVD app.

NeoMac · Jan 18, 2002, 02:41 PM

Originally posted by scottiB:
<STRONG>iMovie2 has an export selection for iDVD. If you want, you can export them ahead of time and drop the finished .movs into the iDVD app.</STRONG>

When iMovie2 exports the selection, is it compressing it as MPEG2? Or is the export just a file config thing?

I want to be crystal clear on this:
If I buy a 20GB drive, can I fit 90 minutes of edited (in iMovie2) DV footage, including all the rendered fades, transitions, titles, music, etc?? Then put all that suff on the 20GB drive and take it to a G4 with SuperDrive. Copy it over and plop it in iDVD for compression and burning?

Sorry, for the nit-picking, I'm a very detail-oriented person.

NeoMac · Jan 18, 2002, 05:44 PM

Ahhhh, don't bother guys. I'll just get a 30GB drive. I'm sure the extra capacity will come in handy and I won't have to constantly worry about not having enough. It's an extra $150 bucks (internal) ... but I'm going to see what it will take to build an external drive or buy an external.

Tnx.

[ 01-18-2002: Message edited by: NeoMac ]

scottiB · Jan 18, 2002, 06:58 PM

When iMovie2 exports the selection, is it compressing it as MPEG2? Or is the export just a file config thing?

It's just a file config thing, basically all settings at the highest (720x480, 29.97 fps, etc). iDVD, itself, does the mpeg-2 compression from .mov files.

If you export ahead of time, you just need to use iDVD on your pal's G4. If you bring the iMovie project folder, you'll need to export it from his cut of iMovie2 (which probably'll be faster on a G4). Make sure that he has all the plug-ins installed that you have--like the Apple Plug-In Pack installed found here.

[ 01-18-2002: Message edited by: scottiB ]