[MacDV] Storage

[Donald Tully]

Derek - That is far and away the best, most concise explanation of  
file converting, compression and storage needs than I have ever read.  
You've answered my question thoroughly. I thank you for taking the  
time and obvious effort to explain the issue so well. I'm sure others  
on this list will benefit from your knowledge, as well.

Kindest regards,
Don Tully


On Feb 16, 2010, at 4:52 PM, Derek Roff wrote:

> I think we've got some terminology problems in this discussion.  By  
> the description of your process, it sounds like you are converting  
> your VHS tapes to DV25 video (often called simply "DV"), and editing  
> it in iMovie.  This is what I do.  This kind of digital video takes  
> up a bit more than 13 GB per hour, and iMovie lists its resolution  
> at 640x480. (Other video programs may call the same video 720x480).   
> You can't make that hour of video any smaller in file size, without  
> changing its format or resolution in some way.  Usually, that means  
> applying some kind of additional compression.
>
> iDVD does, that, converting the DV video into MPEG2.  You have some  
> compression choices, and iDVD will make some choices for you,  
> depending on the amount of video you are trying to put on a disc.   
> But at the iDVD default for one hour of video, the file size will  
> probably be near 4 GB.  The resolution will still be the same as  
> what iMovie calls 640x480.  It will just be compressed in a  
> different way.  You can also export from iMovie to QuickTime, and  
> choose to modify the format, compression, and resolution, if you  
> desire.  You can get pretty good looking MPEG4 video at the same  
> iMovie 640x480 resolution, and compress to somewhere around 750 MB  
> per hour.  That's what I do, before uploading to YouTube.  YouTube  
> then compresses and converts the format yet again, and changes the  
> resolution.
>
> Based on the file sizes quoted below, we can draw some conclusions  
> about Don Tully's video project.  The iMovie project has more than  
> an hour of video in it, although much may be unused and duplicate  
> clips, or things in the trash.  His 3 GB iDVD project is probably a  
> bit under an hour.  And most importantly, we can conclude that the  
> QuickTime movies in the Garage Band and iDVD folders do not contain  
> the video. There is no way that a 4.4 MB or 2.6 MB file can contain  
> any useful amount of video. It does no good to archive these files  
> by themselves. If you copied these files to another computer, they  
> could not play. These files contain pointers to the actual video  
> files.  They can play the video on any given computer, only if they  
> can find their corresponding video files.
>
> Jumping back to the original question of what to save on the hard  
> drive, the answer depends on future goals and needs.  Will you need  
> to access all of the raw footage later for possible re-editing.  If  
> so, you will need a lot of storage.  If your ready to dump the raw  
> material, but think you might do a bit more polishing of the  
> project, then keeping the iMovie project might make sense, after  
> getting rid of the trash and unused shots.  That would bring an hour- 
> long project down to about 13 GB.
>
> If you're planning a bunch of future projects, then a group of  
> iMovie projects may take up too much disk space.  If you don't think  
> you will do a lot of editing later, maybe saving the iDVD project  
> file or the DVD image file would make the most sense.  The two will  
> be similar in file size.  The latter can be created in iDVD, using  
> the File>Save as Disc Image command.  With the disc image, you can  
> burn as many new copies of the DVD as you like, using Disk Utility.   
> With the iDVD project file, you can adjust menus and chapters, add  
> or subtract video clips, as well as burn additional DVDs, making it  
> the more flexible choice.  In either case, if you really want to  
> edit again, you can extract the video and turn it back into DV video  
> with MPEG Streamclip. There will be some quality loss, but it is an  
> option.
>
> Derek
>
>
> --On Tuesday, February 16, 2010 12:00 PM -0800 macdv-request at listserver.themacintoshguy.com 
>  wrote:
>
>> Hi Listers - I have a rather elementary question about the most
>> efficient way to store iMovie and iDvd projects.  I am converting old
>> VHS tapes to DVD. I edit them using iMovie and then send them to
>> iDvd   to burn.  When I'm done I have a 27GB iMovie project, and 3 GB
>> iDvd   project, a 4.4 MB Quiktime movie in my Garageband folder and a
>> 2.6 MB   QT movie in my iDvd folder.  I'd like to keep something on
>> my hard   drive for future reference.  What's the best way to do
>> this, please?
>
>
>
> Derek Roff
> Language Learning Center
> Ortega Hall 129, MSC03-2100
> University of New Mexico
> Albuquerque, NM 87131-0001
> 505/277-7368, fax 505/277-3885
> Internet: derek at unm.edu
>
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