Black border issues when using clips that contain different resolutions

I’m somewhat new to video editing.
I know this subject has been talked about in various ways in this forum
as I browsed the forum searching “resolution”, etc.
I have a camera that takes videos at resolutions
640x480 and 1280x720.
Months ago I took a bunch of 640x480 videos.
Now I do all at 1280x720.
I do wish to use some of the older 640x480 clips in my projects,
though most of the clips I use in projects now are 1280x720.

I’m wondering if there’s a common way in Shotcut for dealing with a project
that uses clips with various resolutions. Like perhaps a preferred method for dealing with clips of various resolutions within a project.

Basically I’m trying to get rid of the black border issue in the final export.

I’d like to somehow enlarge the 640x480 to fill the screen, but in handbrake
I cannot get 640x480 to get any bigger. I think the 640 can go up, but the 480 number seems to not budge.

I probably just need to do a bunch of Shotcut export tests with various export settings.

Mainly I’m writing this to see if there’s a common workflow for getting no black borders
in the playback on my tv when I use various video clip resolutions in my Shotcut projects.

Thanks for any ideas.

You’re dealing with two different aspect ratio’s.
640x480 is 4:3 aspect ratio (in the picture below, green is 4:3)
1280x720 is 16:9 aspect ratio. (blue color)

To have no border, you have two choices.

  • Crop top & bottom of the 4:3. (maintains the 16:9 ratio)
  • Crop left & right of 16:9. (maintains the 4:3 ratio)

You could add a decorative border around the 4:3 to keep the 16:9.
You could have the 4:3 all the way to the right with some sort of picture or text on the left.

Going off on a tangent here… Have video in 16:9, say of waves crashing, have that be your border, then put in the 4:3 video.

You could do what Hudson555x suggested or use the Crop filter with Center bias to fit the image and remove the borders.


Wouldn’t that just crop the top and bottom of the 4:3 video? Thus leaving no borders within 16:9.
If you’re working within 16:9 you’re still going to have borders with 4:3 video.

Maybe I’m missing something here that I’m not quite understanding.

This is a 640x480 image with the crop filter applied.

This is it before the crop.

The image will fit the screen but some bits will be cut out.

Okay, I’m trying the various techniques you both mention.
Thank you both for the detailed descriptions.
If I do crop the 16:9 to maintain the 4:3,
the export still has black borders here, now on both clips.
maybe something to do with my export settings.
Note that I’m thinking since one clip is 1280x720 and the other clip in my test project is 640x480 that it seems like I would need to crop out 640 from the 1280 width,
so I tried cropping out 320 from both left and right. 720-480=240, so I cropped out 120 from both top and bottom of the 1280x720. The result is that now they both show up in the exported video with black borders. I’ll do more tests.
The crop with center bias on the 640x480 seems to get the result I want where both clips in the exported video fill the whole screen on my tv. There’s a good bit of loss of the top and bottom of the 640x480 clip though.
I guess with using clips of various resolutions and various aspect ratios one will definitely end up with a final video export that has either some black borders, or some loss of some of the image areas.
Thanks for the ideas and techniques to try.

Regarding the math…

If you want to crop a 16:9 clip to be 4:3, you take the shorter side, 720, and multiply it by 4/3. I like to think of “4:3” as being “4x:3x” and the way to find X is, if we know the shorter side, in this case 720, divide by 3. Now we have X=240, so multiply by 4, and you get the longer side (4*240=960). 960 is your target width, so take the original width 1280 and subtract the target width 960 to get the total amount that you need to crop. Maybe this graphic will make some kind of sense:


If you wanted to crop a 4:3 clip into 16:9, once again find the common side, in this case width, 640, and multiply it by 9/16. 640*9/16=360, so the height needs to be 360. 480 is the original height, so crop (480-360)/2 from top and bottom.

If you want to have a 4:3 scale video, you’ll need to make a new project with a custom video mode specifying the 4:3 aspect ratio resolution you wish to have. Then bring in your clips. Then just crop just the 16:9 videos.

Thank you for those details. I may look into that. It looks interesting.
I’m hoping to not have to do much calculating like that though. But I do appreciate you diagram and explanations for future reference. For now I just crop by eye, and use the crop with “Center” checked. That works nicely usually to fill the preview screen in some cases.
So I really don’t have all the resolution, aspect ratio, cropping, etc worked out. But I want to get on with editing, so I’ll dive in and hack away at it, doing test exports until I get the results I like. Thanks for the ideas.