Why are my .mov files so large?

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Why are my .mov files so large?

I’m trying to understand how much hard drive space I’m going to need for videos recorded with my new panasonic TM700 camcorder. I’ve been recording in the HA setting (17Mbps). According to the specifications I should be able to shoot 4 hours and 10 minutes of video with the 32 GB of internal storage = ~8 GB per hour. Yet when I import the video into iMovie 11 (which incidentally is even slower than importing my old miniDV files) I get .mov files that are about 1 GB per minute = 60 GB per hour. Why are the .mov files bigger than the original raw data? I’m going to need to buy an 8 TB drive at this rate. Am I doing something wrong with the import? Very confused.

iMac 2.66 GHz coreDuo, Mac OS X (10.6.5)

Posted on Dec 19, 2010 6:23 AM

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Answer 1

Tom Wolsky

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152,777 points

Dec 19, 2010 6:28 AM in response to KCS9999

iMovie is converting to media to QuickTime in an editable codec. That used by the camera is very heavily compressed and not suitable for post production work. The format and codec used is requires a much higher data rate and takes up much more space.

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Answer 2

KCS9999 Author

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Dec 19, 2010 8:04 AM in response to Tom Wolsky

So is there a way to store the raw data at the 8 GB per hour rate on my hard drive and still be able to play it (assuming I'm not interested in editing it)? Or could I store the raw data files on my hard drive and then import them into iMovie for editing from the hard disk? The files on the camera are .mts files that my Mac calls an executable file.

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Answer 3

Tom Wolsky

Level 10

152,777 points

Dec 19, 2010 8:11 AM in response to KCS9999

You can store it, but you can't play it without converting it. To store it, make a folder with some useful name and copy the entire card and its complete folder structure into the folder; or you can make a disk image of the card and its contents.

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Answer 4

KCS9999 Author

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Dec 19, 2010 8:23 AM in response to Tom Wolsky

Thanks. I'm now thinking I may just buy a 2 TB firewire drive and store the files as .mov. That should give me about 33 hours of video. By the time I fill that up, drives with 10s of TB should be the standard.

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Answer 5

Dec 19, 2010 9:46 AM in response to KCS9999

You can use either VLC or Movist to play the raw MTS files. Both are free.
Shedworx also has a quickview plugin which lets you preview your MTS files via finder. It will also playback using dropped frames if neccessary.

Movist actually drops frames in order to achieve a smoother playback. Naturally that affects the viewing quality.

Good quality playback of MTS files (h.264) is rather taxing on your system so I would say your system will definitely have choppy playback.

HTH

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Answer 6

KCS9999 Author

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Dec 19, 2010 5:59 PM in response to mattias.rylander

Thanks for the tip about Movist. It worked well for viewing the raw MTS files. I was able to drag the MTS file (full 1080P data) onto my desktop and play it with Movist. The playback was excellent quality with very little choppiness. I was hoping to be able to store the files this way and then when I wanted to play with them, import into iMovie. Unfortunately, I am not able to import the file from the desktop, I can only import from the camera (well not the 1080P file but a different 1080i file). Does anyone know how I can import the MTS file into iMovie from my hard drive, not the camera?

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Answer 7

Tom Wolsky

Level 10

152,777 points

Dec 19, 2010 6:37 PM in response to KCS9999

Import>Camera Archive and point to the folder that contains the archived card.

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Answer 8

Dec 20, 2010 12:51 AM in response to KCS9999

Since the AVCHD actually is a whole structure, with specifics for each manufacturer, it is easiest to keep a backup of the entire card.

Do an image of the card by using the built in DiskUtility. When you have the card mounted and it shows up in DiskUtility, click on the drive (named like the device that holds the memory card) and click the "Create image" (or similar) icon in the menu. Create an image which is readonly (to prevent OSX from placing index files) and store it somewhere safe.

When you want to import files to iMovie, just mount the newly created image and iMovie will treat it like the real thing, including all metadata.

Copying the MTS files alone off the memory card will not retain some metadata, however when using iMovie, you won't need it anyways. As iMovie won't import standalone MTS files you can choose to either put them into an AVCHD structure as above (an iMovie archive is basically the same) or use a third party tool to convert them from MTS to a Quicktime format. The latter is easier and can be accomplished using the free MPEGStreamclip. Convert to AIC (iMovie internal format).
As iMovie uses the creation timestamp when importing single clips, you can use terminal to "touch" the files to the correct date if you know this. Or just fix it in iMovie itself.

HTH

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