Bug 353019 - 15.13.0 git master - Chroma key effect not working -- leaving burned image of keyed clip in monitor
Summary: 15.13.0 git master - Chroma key effect not working -- leaving burned image of...
Status: RESOLVED FIXED
Alias: None
Product: kdenlive
Classification: Applications
Component: Effects & Transitions (show other bugs)
Version: unspecified
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Vincent PINON
URL: https://www.youtube.com/watch?v=HlQ2e...
Keywords:
Depends on:
Blocks:
 
Reported: 2015-09-22 03:44 UTC by Unknown
Modified: 2016-03-02 16:51 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed In:


Attachments
Watch this video I made with audio narration to see an example and details of issue. (28 bytes, text/plain)
2015-09-23 19:16 UTC, Unknown
Details

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Description Unknown 2015-09-22 03:44:26 UTC
See video example in URL.

When I apply the blue screen effect, then choose the color I'd like keyed out, it keys out the color from the clip, but there's still a burned image of the video clip behind that, which overlays any of the clips below it in the timeline.

Reproducible: Always

Steps to Reproduce:
1. Add clip to timeline, then add green screen clip in track above the previous clip.
2. Apply the blue screen effect to the clip with the green screen in it
3. In the effects stack, choose the color to be keyed out

Actual Results:  
Color is keyed out, but some kind of burned image is still present from the keyed clip, which is showing in front of all the clips behind it.

Expected Results:  
The key effect should key out the desired color entirely, showing anything in the below track(s) in the timeline.

Using Kdenlive 15.09.0 from kubuntu-ci/unstable ppa on Kubuntu 15.10 beta x64.
Comment 1 Roger Morton 2015-09-22 09:52:11 UTC
You do not mention the use of transition in your description on how to reproduce.
I don't think you are using the effect correctly.
Have a read of https://userbase.kde.org/Kdenlive/Manual/Effects/Alpha_manipulation

You need to have a composite transition in the project for "Blue Screen" to work
Comment 2 Unknown 2015-09-23 00:33:08 UTC
Roger, I tried adding a composite transition between tracks, but it didn't have any affect. This could be related to the bug I reported about not getting any transitions to work in 15.09.0, but I'm not sure. (See https://bugs.kde.org/show_bug.cgi?id=353024)

Adding a Pan and Zoom effect, however, does fix the issue, and the transparent green in the above video is now fully keyed out, showing the clip underneath it.
Comment 3 Unknown 2015-09-23 00:57:04 UTC
Here's a video when I try to add the blue screen effect after applying a composite transition between two tracks.

https://youtu.be/u-YOF_WSVnI
Comment 4 Unknown 2015-09-23 18:56:11 UTC
After reading a post from Vincent in a different bug report, it turns out that tracks now have composite embedded in them (and I think are enabled by default). If they aren't, there's a new icon in the track header to enable/disable the composite function.

However, even with composite enabled, the Blue Screen effect still isn't keying out the background properly; It's leaving a green tint over the track content beneath it.

Again, see the videos for examples.

Confirmed this issue as well in 15.08.1+git20150923.0031+15.10-0_amd64, which I downloaded and installed, yesterday.
Comment 5 Unknown 2015-09-23 19:16:03 UTC
Created attachment 94696 [details]
Watch this video I made with audio narration to see an example and details of issue.
Comment 6 Unknown 2015-11-26 20:46:56 UTC
This bug is still present in Kdenlive 15.11.80 development build.

See this video for example: https://youtu.be/Q8n0ksj-6mo.
Comment 7 Unknown 2015-11-26 20:55:38 UTC
Updated bug title to reflect the latest development build that still has this bug present, 15.11.80.
Comment 8 Unknown 2016-01-08 19:21:29 UTC
Bug is still present in Kdenlive 15.13.0 development version (Kdenlive-git in Arch/Antergos).
Comment 9 Unknown 2016-01-08 19:23:12 UTC
I should also mention that adding an Affine transition on the clip with the chrome key effect will make the effect work normally; there's no burn-in. But removing the Affine transition and turning on composite brings the burn-in issue back.
Comment 10 Unknown 2016-02-26 18:59:59 UTC
This bug is still present in the latest 15.13.0 git master. JB, I added you to the cc list in light of the recent fixes with the composite multitrack fix in the timelines. I figured this issue might be closely related?
Comment 11 Jean-Baptiste Mardelle 2016-02-26 20:13:56 UTC
I cannot reproduce the problem. Works fine for me with auto track composite. Could you attach / mail me a sample project with files so that I can try to reproduce ? You can create a compressed archive from a project in:
Project > Archive Project
Then check the "Compressed archive" checkbox.
Comment 12 Unknown 2016-02-26 21:38:11 UTC
Thanks for looking into this JB. Yessir, making a sample project right now.
Comment 13 Unknown 2016-02-26 22:01:23 UTC
You should have it in your e-mail.

Here's also a video of the issue using the latest 15.13.0 master git build: https://youtu.be/joYrS1nM3Jo.
Comment 14 Jean-Baptiste Mardelle 2016-02-26 22:04:49 UTC
Ok, I found the problem that caused both this and the composite font transparency issue.
The auto composite transition is a frei0r transition. There was a bug in older frei0r transitions that bleeded image transparency:
https://github.com/ddennedy/frei0r/commit/63808414a36882b8bdd397aa24d5f61450151c4c

It was fixed in november in Dan Dennedy's frei0r repository. Where did you get your frei0r plugins ?

By the way, the effect "color selection" seems to be a much better better effect for chroma key... have you tried it ? Maybe we should rename it...
Comment 15 Unknown 2016-03-02 16:51:46 UTC
You're right, JB. I just tested this in Kubuntu running KDE 5.5.4, and, lo and behold, it works perfectly! I got my frei0r package from Olivier Banus's sunab ppa: https://launchpad.net/~sunab/+archive/ubuntu/kdenlive-svn/+packages?field.name_filter=&field.status_filter=published&field.series_filter=wily. It seems to do the trick.

Also... wow, the color selection tool is MUCH, MUCH better for chroma keying. You're absolutely right. Honestly, I would rename the "Color Selection" effect to "Chroma Key", and do away with the current chroma key effect entirely. The features on the Color Selection effect allow for a much, much cleaner keying of the clips. That's my suggestion.

However, the terms used in the Color Selection effect are REALLY programmer-esque. I have no idea what most of them mean, so the only way I could test them was to play around with them; trial and error. After a little more tinkering, I could suggest some more film-friendly terms to use. :)

Either way, I switched back to Kubuntu as my primary working distro, for reasons exactly like this. So, on Kubuntu, it seems to be working fine.

JB, I'm not sure how to want to mark this bug, being that it seems the issue is with the frei0r package in the Arch repo's (or possibly the AUR). Invalid? Upstream?

Thanks so much for looking into this for us.