12GB per hour of HD footage instead of 29GB?

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Level 1

8 points

12GB per hour of HD footage instead of 29GB?

Hi,

I recently switched over to HD camera (Sony HDR-HC1E). This is a DV tape cam.
Im editing in imovie 6.0.4.

I always back up my files by exporting via imovie "full quality" when i used to do this with SD content i would get a DV file as result, now on HD i get a .mov file.

I used to get a 12GB file for a 60min movie. Now with HD i am getting 29GB per hour.

I hear other people talking about 12GB per hour for HD content.

Can anyone please tell me how this is possible?

I am going through external hard drives at lightning speed!

Thanks
Dave

Mac OS X (10.4.8)

Posted on Mar 8, 2010 5:13 AM

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Answer 1

Mar 8, 2010 6:34 AM in response to Dieop

miniDV/Standard is ~13GBs/h
miniDV/HDV is ~13GBs/h on tape.. on import, it gets automatically converted into a different, editing codec (AppleIntermediate), which has ~ 30-40GBs/h.

on export back to cam, your aic.mov gets converted back to HDV.
on authoring in iDVD, it will be 'shrunked' to 2-4GBs/h ..
for web-usage, or on iPod or.. you can compress it even more..

summary:
+all within normal parameters+ .. 😉

Matt Clifton wrote:
... You can choose to optimize video on import (large, rather than full size) ...

not with iMHD6, Matt .. topic on this sub-board.. 😉

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Answer 2

Mar 8, 2010 6:39 AM in response to Dieop

Hi Dave

There's actually a big difference between a DV stream (whether recorded to tape or file) and a .mov file.

DV or HDV footage is recorded at 25Mbps - megabits per second. This translates to 90000Mb per hour, divide by 8 to convert bits to bytes, and you get 11.2GB/hour. That's constant, whether on the tape or saved as a DV file. Note that DV is pretty compressed.

Now, when iMovie (or any other video conversion program) saves a .mov file, it's no longer a DV stream. It can be any of the codecs (video formats) that your program supports, and there are a wide range of codecs for both SD and HD. These different codecs will use different file sizes depending on their level of compression. (Just like mp3, a compressed audio codec, vs AIFF, an uncompressed codec.)

You can choose to optimize video on import or choose a smaller format on export (large, rather than full size) which will reduce the frame size of your footage, which may be a good solution for you, depending on what you ultimately plan to do with the material. (Edit: actually, not with iMovie 6 - thanks, Karsten 🙂 Newer versions of iMovie will help you there. )

Matt

Message was edited by: Matt Clifton

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Answer 3

Dieop Author

Level 1

8 points

Mar 8, 2010 6:37 AM in response to Karsten Schlüter

Thanks Karsten,

I convert my clips into various formats for web use, wmv, mov, divx...

But is there any way to store the original files on an external drive (uncompressed DV or mov) at 12GB per hour of content?
Or do i have to keep it at aprox 30GB content?

I don't store my clips on DV tape.

Thanks again
Dave

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Answer 4

Dieop Author

Level 1

8 points

Mar 8, 2010 6:43 AM in response to Matt Clifton

Thanks Matt,

I always thought that converting to "full quality" form the imovie export feature gave me an uncompressed file (DV).

Since switching to HD, i have filled 4, 1.5 TB drives!

I must have been mistaken about what i read, i thought it was possible to export one hour of HD into 12GB.

My main reason for keeping my edited clips in uncompressed form is that things are always changing and new media players are coming out. If i have the original edited files stored on drive they are easy to re make into any format.

Thanks
Dave

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Answer 5

Mar 8, 2010 6:55 AM in response to Dieop

Dieop wrote:
.. is there any way to store the original files on an external drive (uncompressed DV or mov) at 12GB per hour of content?

unfortunately, only FinalCutPro is able to handle HDV 'natively'.

Or do i have to keep it at aprox 30GB content?

you can keep only the large aic.mov but ..
why not keeping the tapes?
Excellent long-term-storage track-record, no loss, no conversionss, no backups.. 'raws'.

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Answer 6

Dieop Author

Level 1

8 points

Mar 8, 2010 7:06 AM in response to Karsten Schlüter

Thanks again Karsten,

The main reason i don't keep back up on tape is that in an our tape i have roughly 12 clips. If i have to capture and re split the clips it would take more time, also GB's are cheeper for storage now anyway.

Dave

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