iMovie and File Format

I use iMovie because predictably it's "free" if you own or have access to a Mac.  Arguably it's an easier to use video editing software and relatively stable.  I used a bunch of Linux video editing software and they just crashed and burnt every few minutes.

Here is the biggest discovery ever for me.

I notice iMovie actually lags when editing, that's it stutters as I try to edit the footage or video clips.  That prompted me to try out Final Cut Pro X and the problem went away, seemingly.  After my FCPX expired after the one-month trial period, I was hard pressed to pay $300 to own a working copy.  I mean if you make money out of it, it seems like a bargain.  I am going to spare my thoughts on this.

After some Google searches, I think I found out why the stuttering.  I think it has to do with the source file format.

In FCPX, I edit the MOV files directly from my Nikon D7000, as I can de-squeeze my anamorphic footage in FCPX without changing the file format first.  I don't remember if I ever used HandBrake to un-squeeze and then edit in FCPX and if so did it show any lagging at all.

iMovie doesn't allow me to un-squeeze the footage while editing.  So I used HandBrake to un-squeeze the footage to 2.35:1 and along the way I think I compressed the file quite a lot.  And I think hence the difficulty of iMovie when editing.  I am assuming iMovie has trouble editing "highly" ompressed mp4 files.  The file was changed to mpeg4 in mp4.

I now de-squeeze files in H.264 (default mpeg4) in mp4 and retain a higher bit rate at 8000kb/s (default is 1000).  When I edit them in  iMovie, it doesn't lag anymore.

A word of caution:  I really don't know for sure, just want to share my experience.  When it becomes technical stuff which video editing is, I just test it out to see what works or works better without spending tons of money or time reading up.

Also, I use a Nikon hack to increase the recording bit rate at I think 65mbps in 1080p at 24fps.  I am sure along the way when I use HandBrake to de-squeeze a lot of data are lost.  Still when editing the stutter goes away.