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JDLang76

macrumors regular
Original poster
Jan 1, 2018
155
57
Have 22 feature length films in 4k all form the same source. MP4. 2 channel AAC audio. Every setting is exactly the same from source.
Here's how I render them in iMovie. I chop up the credits real quick, play through those few seconds, and then the whole movie renders. Usually creates about 500gb give or take. After it is rendered, I can then edit the 4k footage completely smooth. Never had an issue.

Recently, for a hardware upgrade, I deleted all the render files (using imovie preferences) to make the data transfer easier. After, I let each project play from start to finish, and each one again rendered its 500gb-ish render files. They all function properly except one.

One movie only created about 80gb render files and when I watched the whole thing in imovie, i am getting stuttering all over the place. And its NOT at the transition moments. Its at completely random parts. I tried deleting the render files and trying again but I got the same problem. Again, the same exact specs of 4k video from the same source as the other 21 and I didnt have this problem before, nor have I had it on any other project.

Its not a HW limitation obviously - (the HW upgrade was just adding more storage)
Mac Pro 5,1
High Sierra (HFS+)
dual X5690
1080 ti with web drivers up to date
128gb ram
Editing off of 550Mb/s RAID 0 WD Black drives

Can anyone help with this? Im stumped.
 

Dave Braine

macrumors 601
Mar 19, 2008
4,000
359
Warrington, UK
when I watched the whole thing in imovie, i am getting stuttering all over the place.
Is this when watching from the Timeline? I get the same with AVCHD footage. It plays fine when viewing the clip in an event, but it stutters in the Timeline. it eventually smooths out, but if I drag and extend the clip, the new bit stutters. However, If I export/share the movie as a video file, it plays fine.

Have you tried exporting?
 

revmacian

macrumors 68000
Oct 20, 2018
1,745
1,468
USA
Have 22 feature length films in 4k all form the same source. MP4. 2 channel AAC audio. Every setting is exactly the same from source.
Here's how I render them in iMovie. I chop up the credits real quick, play through those few seconds, and then the whole movie renders. Usually creates about 500gb give or take. After it is rendered, I can then edit the 4k footage completely smooth. Never had an issue.

Recently, for a hardware upgrade, I deleted all the render files (using imovie preferences) to make the data transfer easier. After, I let each project play from start to finish, and each one again rendered its 500gb-ish render files. They all function properly except one.

One movie only created about 80gb render files and when I watched the whole thing in imovie, i am getting stuttering all over the place. And its NOT at the transition moments. Its at completely random parts. I tried deleting the render files and trying again but I got the same problem. Again, the same exact specs of 4k video from the same source as the other 21 and I didnt have this problem before, nor have I had it on any other project.

Its not a HW limitation obviously - (the HW upgrade was just adding more storage)
Mac Pro 5,1
High Sierra (HFS+)
dual X5690
1080 ti with web drivers up to date
128gb ram
Editing off of 550Mb/s RAID 0 WD Black drives

Can anyone help with this? Im stumped.
Have you tried the free version of Davinci Resolve? My experience was much more enjoyable after moving from iMovie to Davince Resolve. Davinci Resolve can be downloaded here: https://www.blackmagicdesign.com/products/davinciresolve/
 

JDLang76

macrumors regular
Original poster
Jan 1, 2018
155
57
Is this when watching from the Timeline? I get the same with AVCHD footage. It plays fine when viewing the clip in an event, but it stutters in the Timeline. it eventually smooths out, but if I drag and extend the clip, the new bit stutters. However, If I export/share the movie as a video file, it plays fine.

Have you tried exporting?
I havnt tried exporting. Ill do that tomorrow and see if the finished product is ok
[automerge]1587693199[/automerge]
Have you tried the free version of Davinci Resolve? My experience was much more enjoyable after moving from iMovie to Davince Resolve. Davinci Resolve can be downloaded here: https://www.blackmagicdesign.com/products/davinciresolve/
Thanks but ive got 44 hours of footage and 3 years of work into this project. Aint startin over now 😎
 

ColdCase

macrumors 68040
Feb 10, 2008
3,364
276
NH
On lower power machines or one using any kind of hard drive for the library, RAID or not, I often see stuttering scrubbing the time line on challenging source formats. Its a good test of your editing machine performance. I rarely see stuttering editing off a SSD. I don't think iMovie supports proxy editing, but using proxy is the way many get around it.

Exported/shared, the video will play just fine.
 

JDLang76

macrumors regular
Original poster
Jan 1, 2018
155
57
On lower power machines or one using any kind of hard drive for the library, RAID or not, I often see stuttering scrubbing the time line on challenging source formats. Its a good test of your editing machine performance. I rarely see stuttering editing off a SSD. I don't think iMovie supports proxy editing, but using proxy is the way many get around it.

Exported/shared, the video will play just fine.
If you’d read the OP, you’d know why that is not the issue at all.
 

ColdCase

macrumors 68040
Feb 10, 2008
3,364
276
NH
If you’d read the OP, you’d know why that is not the issue at all.
I was just saying that he is using rotational drives in a RAID configuration, and that may be the source of the stuttering, I’ve been there, done that, I have a 5.1 myself.
 
Last edited:

JDLang76

macrumors regular
Original poster
Jan 1, 2018
155
57
I was just saying that he is using rotational drives in a RAID configuration, and that may be the source of the stuttering, I’ve been there, done that, I have a 5.1 myself.
"On challenging source formats." All 22 movies are exactly the same. If what you said was applicable, all 22 movies would have the same problem. And regardless of that, the format is MP4 x264 SDR 8-bit AAC. As I'm sure you know, that's about as not-challenging of a format as you can get.
 
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