Compressing a .mov?

mikeford

Diamond Member
Jan 27, 2001
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compressing a compressed file gets you a change in the suffix, but maybe a larger file.

For example you could zip a .mov and get a .zip file, but it won't be much if any smaller and could be larger.

You could also reencode the file to higher compression rate or different codec, like Divx, but that usually results in artifacts since each lossy codec removes different information based on what it thinks you won't notice, or what it hides well.
 

Bluestealth

Senior member
Jul 5, 2004
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I once compressed a bunch of .movs that were inside a large folder full of junk... when I uncompressed the archive a year later to remove a lot of stuff from it, they were all unwatchable... audio still worked fine, but the video looked was cut into 4 looping diagonal sections that wern't timesynced... this was qt5... also where some black and white bars.

BTW the only way that I can think of compressing them is to open the up and save them as a h264 Quicktime 7 video(don't know if this is possible, I will never buy apple products).... Zipping them will not save space... and apparently in my case... ruined them...
 

vegetation

Diamond Member
Feb 21, 2001
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Originally posted by: Bluestealth
I once compressed a bunch of .movs that were inside a large folder full of junk... when I uncompressed the archive a year later to remove a lot of stuff from it, they were all unwatchable... audio still worked fine, but the video looked was cut into 4 looping diagonal sections that wern't timesynced... this was qt5... also where some black and white bars.

BTW the only way that I can think of compressing them is to open the up and save them as a h264 Quicktime 7 video(don't know if this is possible, I will never buy apple products).... Zipping them will not save space... and apparently in my case... ruined them...

That's simply not possible. You had some other issues causing the corruption. I would say something with your video codec, since your audio portion worked fine (classic sign).

 

Jeff7

Lifer
Jan 4, 2001
41,596
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Originally posted by: vegetation
Originally posted by: Bluestealth
I once compressed a bunch of .movs that were inside a large folder full of junk... when I uncompressed the archive a year later to remove a lot of stuff from it, they were all unwatchable... audio still worked fine, but the video looked was cut into 4 looping diagonal sections that wern't timesynced... this was qt5... also where some black and white bars.

BTW the only way that I can think of compressing them is to open the up and save them as a h264 Quicktime 7 video(don't know if this is possible, I will never buy apple products).... Zipping them will not save space... and apparently in my case... ruined them...

That's simply not possible. You had some other issues causing the corruption. I would say something with your video codec, since your audio portion worked fine (classic sign).

Agreed. Compression like ZIP or RAR is lossless. The archive must have suffered damage at some point in time. Because otherwise, you should be able to decompress your video in 50 years and still get exactly the same thing.
 

JimPhelpsMI

Golden Member
Oct 8, 2004
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Hi, Zip compression does not alter any file. If the file is already compressed you will not get any or little compression. KPZIP, WinZip, PowerZIP etc. are all suitable. Jim
 

Bluestealth

Senior member
Jul 5, 2004
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I'll have to try it out again... not sure I can locate any quicktime 5 files to it with though... I was using Winrar 2.98beta(?) best compression, solid, locked, with no recovery record... was transfered twice between harddrive as I was getting rid of them, and totaled to be about 1.7 gigs and uncompressed without any errors.... considering it was a group of qt5 from a specific source... and I was tyring to play them with qt6 it might be that apple broke something with the codec that was used to encode them... they were orginally playable on qt5 without any plugins but not on my qt6, but I also tried a qt5(reinstalled after using qt6 though) player and they no longer worked... could it have been something that I choose while compressing that made it loose something?
 

JimPhelpsMI

Golden Member
Oct 8, 2004
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Hi Blue, I can't think of anything you could do wrong when compressing a single file. All the ZIPs should Zip and Unzip them without damage!!!! Luck, Jim
 

wseyller

Senior member
May 16, 2004
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reencode with a different bitrate.

as for the file itself, not so much can be done, as quite probably the file
is already compressed, further size reduction is likely to cost in terms of
quality.
 

JimPhelpsMI

Golden Member
Oct 8, 2004
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Hi, A Zip compression is not like a JPG compression. NO DAMAGE is done to the file. It will UnZip and be the same as when you started. Jim