View Issue Details Jump to Notes ] Issue History ] Print ]
IDProjectCategoryView StatusDate SubmittedLast Update
0001630KdenliveEffectspublic2010-05-30 04:152010-08-11 11:45
Assigned To 
PlatformOSOS Version
Product Version0.7.7.1 
Target VersionFixed in Version 
Summary0001630: No way to use video masks for compositing 2 videos.

In image editors you can often use a layer mask to provide the level of alpha transparency.

The best I could manage was using the blue screen to composite a foreground image multiplied with the black and white mask, and the background.

This is bad since a) it doesn't have alpha transparency, only binary and b) you cannot use pure black (0,0,0).

Attached images are illustrating what I was trying to do. With this feature Kdenlive would be able to manage a TON of additional effects.
TagsNo tags attached.
Build/Install Method(select)
Attached Filespng file icon layers.png [^] (5,735 bytes) 2010-05-30 04:15

png file icon mask.png [^] (3,093 bytes) 2010-05-30 04:15

png file icon result.png [^] (7,870 bytes) 2010-05-30 04:15

jpg file icon menu.jpg [^] (75,327 bytes) 2010-06-03 03:02

- Relationships

-  Notes
genjix (reporter)
2010-06-02 10:37

I think that you should get rid of needing composite to overlay 2 videos. It should just work as the videos should have an alpha channel.

That way the effect (e.g Blue Screen or whatever) just modifies the alpha channel and the videos underneath show through.

This way you could have an effect like I described in the OP that uses a monochrome video as the current clip's alpha channel.
LeHomard (developer)
2010-06-02 12:49

Using an alpha channel for the clips (videos and pictures) would be ideal. Adding transparent pngs would be straightforward, and compositing would be a breeze.

It seems to be the way OpenShot works : [^]

OpenShot being also based on MLT means that it should be possible in Kdenlive, but that would probably mean quite a lot of work to change from the current system...
genjix (reporter)
2010-06-03 03:00

Not sure if I should discuss this here or move it to the mailing list...

In Blender's Video editor you can also have as many compositions as you want because compositions are stored on their own separate track. This makes working with video a lot more flexible.

Combined with alpha channels in videos (specified by Video Effects) would be so great.

I've uploaded a new example image showing an Add Composition strip between tracks 3>2 (hence the caption on it).
genjix (reporter)
2010-06-03 03:06

I forgot to mention. This means you can have multiple compositions and can work with the result of the composition rather than just the top clip.

Blender also has the ability to combine clips into a metaclip so you just manipulate it as if it was a single clip on 1 track.

In KDEnlive to do the same I have to save the file, make a new project, import that project as a clip. It's not a bad solution still though. But Blender's way is nicer.
LeHomard (developer)
2010-08-11 11:45

Acknowledging as a feature request.

- Issue History
Date Modified Username Field Change
2010-05-30 04:15 genjix New Issue
2010-05-30 04:15 genjix File Added: layers.png
2010-05-30 04:15 genjix File Added: mask.png
2010-05-30 04:15 genjix File Added: result.png
2010-06-02 10:37 genjix Note Added: 0005246
2010-06-02 12:49 LeHomard Note Added: 0005249
2010-06-03 03:00 genjix Note Added: 0005255
2010-06-03 03:02 genjix File Added: menu.jpg
2010-06-03 03:06 genjix Note Added: 0005256
2010-08-11 11:45 LeHomard Note Added: 0005531
2010-08-11 11:45 LeHomard Severity tweak => feature
2010-08-11 11:45 LeHomard Status new => acknowledged

Copyright © 2000 - 2016 MantisBT Team
Powered by Mantis Bugtracker