2 Replies Latest reply: Jan 21, 2013 4:43 PM by John Gerads
jfaughnan Level 3 Level 3 (780 points)

This is not a new behavior, I found a discussion reference on this from 2007. Still, doesn't seem to be widely known.

 

In at least some circumstances, if not routinely, iMovie will decode and reencode a DV file (changing container to .MOV) when a rejected clip is moved to the trash:

 

Gordon's Tech: iMovie '11: deleting rejected clips reduces video quality

 

DV is a lossy format, so reencoding like this degrades quality (noticeably in the case I studied). Note QuickTime Pro (old days) could excise without reencoding.

 

It would be nice if iMovie gave a warning. I don't think it's possible to undo this.

 

My situation is a bit peculiar -- single 10GB clip (A to D conversion) and @2007 .DV format. Maybe this doesn't happen with all DV formats.


iMovie '11, iPhone OS 3.1.2, MacBook Core-2 Duo, G5 iMac, G3 iBook, Mac mini
  • 1. Re: iMovie may reduce video quality when sending clips to trash
    John Gerads Level 1 Level 1 (0 points)

    I'm noticing it now in imovie 11.  Import a video clip in HD, put rejected clips in the trash and the quality of my imported clip is reduced significantly. 

     

    This is frustrating.  Good thing I kept a full copy.  In some of my files, my rejected clips total 5-10GB so it would be nice to get rid of those. 

     

    I'm surprised that there aren't more threads on this.

  • 2. Re: iMovie may reduce video quality when sending clips to trash
    John Gerads Level 1 Level 1 (0 points)

    If the rejected clips are not moved to the trash, but simply remain rejected, the video maintains HD quality.

     

    Interesting, I did a force quit while one file was trashing the rejected clips and I lost the entire file when I restarted imovie.

     

    Seems that imovie took the entire flle to a different place to get rid of the rejected clips, then would dump the "original" clip back into my Events.

     

    Again, I'm surprised that there aren't more threads on this.

     

    Any workarounds?