Lag/Bugs I encountered

Bug
1

Windows 10 Mid-end gaming computer/Shotcut version 23.12.15

Shotcut handles small projects wonderfully. Overall very happy with Shotcut although I had some issues as my project size grew larger (Final length was 55 minutes.)

There are various issues that cause unresponsiveness and growing memory usage. Often results in crash, although sometimes it does resolve:
-Not possible to ripple delete 40+ minutes of material at once (or even 10, or 5 minutes). Have to cut in ~3 minute increments (see image below)
-The undo button is very crash prone, esp. when undoing ripple cuts or transitions. Either the program simply crashes or otherwise exhibits similar unresponsive behavior.
-When moving clips 0 distance, sometimes a transition is created that spans the entire distance to the next clip (I did not manage to recreate on video). Undoing this always takes time and is very prone to crashing

Lag (First Video):
-Moving between tracks is an issue (moving a clip sideways is okayish, but if you touch another track it lags). Much faster was to copy, delete, then insert track in desired lane.
-Directly changing position cooridinates using mouse is laggy. Have to manually input pixel values. Same with fadein/out
-Operations (moving,adjusting fadeins, etc) are much slower when a clip is selected.

Crashes:
-(See rar file) Attached in file is 2 clips that cause crash if you attempt to split, resize (from beginning), or perform ripple cuts of subsections. Seems to be some issue with filters as issues persist even after replacing the original video with an image. Seems unrelated to project size.
-(Second video) There’s a bug where Forward or Forward/Reverse doesn’t on clips if the video doesn’t start from the beginning (This occurs after you re-open the project. Video shows expected vs bugged behavior) I was unable to show the bug live with saving/re-opening on video because trying to change the video start point crashed the application (another bug? 3rd video)

-Not crash related but rejoining clips duplicates the filters on them.

Suggestions:
-More versatility in copying filters . Especially with lag it is difficult to uncheck, copy, then recheck filters.
-The Home button in filter view could take user to beginning of clip or filter range, not entire video
-Increase the area of the resize bar so it is not easy to accidentally drag out the Timeline panel instead
-Excuse the mess of language, but is it possible to have the option of a sort of “1 to 1 pixel subsampling” conversion of color individually pixel to pixel so you don’t end up with Shotcut blurring edges as in this thread: Shotcut changing and blurring colors on image

Had issues uploading, files here: Shotcut - Google Drive

Edit: image

deleting 40 minutes of content in one go copy
deleting 40 minutes of content in one go copy1699Ă—830 170 KB

1 Like
2

I have also encountered errors when rendering any size. position, or rotation after a 30 minute of content. Rendered video just freezes through the entire edited scene.

3

Try to split up your long videos into parts of 10-30 minutes videos and combine the part video projects in an master video with File->“Open MLT as Clip”.

You get the advantage of faster less RAM consuming editing because less thumbnails are loaded in the GUI-RAM and you are faster if you have to check parts in the exported video by part rendering.

Improving the RAM handling is a steady and slow process.

4

This is intentional. Shotcut does not know which filters you want from each clip, and they can be different. You need to decide yourself. If you do not like that, then do not merge. Lift one of the clips and trim the other to fill the time occupied by the other half.

Your bug report has too many items to address especially the lags or the memory consumption. Maybe someone will look at your crash reports.

is it possible to have the option of a sort of “1 to 1 pixel subsampling” conversion of color individually pixel to pixel

You must use an export that does RGB or YUV 4:4:4. Quicktime Animation and still presets do RGB. Look at the pix_fmt in Export > Other. For example, the ten_bit/ProRes444 does YUV 4:4:4. It is extremely rare to deliver video like this even for intermediates. For 8-bit, set/add:
mlt_image_format=rgb
pix_fmt=yuv444p

5

I reproduced and fixed this for the next version 24.01

6

@Alex007 Thanks. That’s a nice workaround.

Absolutely. And if there’s anything you’re looking at and would like information on (crash reports etc) I’ll be more than happy to upload.