Bug 514312

Summary: .mov files without transparency
Product: [Applications] kdenlive Reporter: Jose <jguidusmedia>
Component: Project Bin & ImportAssignee: Jean-Baptiste Mardelle <jb>
Status: RESOLVED NOT A BUG    
Severity: major CC: berndmj
Priority: NOR Keywords: triaged
Version First Reported In: 25.12.0   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: clip .mov con transparencia
Color clip scaled down in Clip Monitor
Clip scaled down in Clip Monitor
Effect panel

Description Jose 2026-01-08 08:35:00 UTC
I've experienced this in previous versions as well. When importing .mov files, the transparent background isn't displayed and is instead rendered black, so some kind of luma effect always needs to be applied.
SUMMARY


STEPS TO REPRODUCE
1. 
2. 
3. 

OBSERVED RESULT


EXPECTED RESULT


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: 
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 Bernd 2026-01-09 18:05:17 UTC
Not all .mov files have an alpha channel. Can you provide a sample of that .mov file that has alpha but rendered black in Kdenlive?
Comment 2 Jose 2026-01-09 18:15:28 UTC
How can I send you a snippet? Yes, it's black and the file has transparency.
Comment 3 Bernd 2026-01-09 20:36:18 UTC
(In reply to Jose from comment #2)
> How can I send you a snippet? Yes, it's black and the file has transparency.

Add it as an attachment here or post a link to a file share if it's too big
Comment 4 Jose 2026-01-10 09:46:57 UTC
Created attachment 188380 [details]
clip .mov con transparencia

El archivo contiene canal alpha pero kdenlive no la detecta
Comment 5 Bernd 2026-01-10 16:33:49 UTC
Created attachment 188387 [details]
Color clip scaled down in Clip Monitor

(In reply to Jose from comment #4)
> Created attachment 188380 [details]
> clip .mov con transparencia
> 
> El archivo contiene canal alpha pero kdenlive no la detecta

Thanks for the clip. It pains me to say that the clip does NOT have transparency.

I have attached two screenshots: one with a color clip that has been scaled down to show the background in the clip monitor, and the other with the clip also scaled down a little. I have set the Clip Monitor background to Checkerboard to see where there is transparency.
Comment 6 Bernd 2026-01-10 16:34:19 UTC
Created attachment 188388 [details]
Clip scaled down in Clip Monitor
Comment 7 Bernd 2026-01-10 16:35:01 UTC
Created attachment 188389 [details]
Effect panel

This shows the Transform effect applied to the clip in the Project Bin
Comment 8 Bernd 2026-01-10 16:41:02 UTC
(In reply to Jose from comment #4)
> Created attachment 188380 [details]
> clip .mov con transparencia
> 
> El archivo contiene canal alpha pero kdenlive no la detecta

According to mediainfo this clip used Apple ProRes 422HQ which doesn't support an alpha channel. ProRes 4444 does according to https://www.andrewgormley.com/post/how-to-choose-the-right-version-of-prores-for-your-project
Comment 9 Jose 2026-01-10 18:59:18 UTC
Comment on attachment 188388 [details]
Clip scaled down in Clip Monitor

En la imagen se sigue viendo sin transparencia
Comment 10 Jose 2026-01-10 19:11:14 UTC
Comment on attachment 188388 [details]
Clip scaled down in Clip Monitor

Maybe I was wrong when choosing the clip, but it has happened to me with many movs. I usually make a lot of animations in Friction with transparent background and mov file, and they don't work
Comment 11 Jose 2026-01-10 19:11:40 UTC
Maybe I was wrong when choosing the clip, but it has happened to me with many movs. I usually make a lot of animations in Friction with transparent background and mov file, and they don't work
Comment 12 Bernd 2026-01-11 01:21:47 UTC
(In reply to Jose from comment #11)
> Maybe I was wrong when choosing the clip, but it has happened to me with
> many movs. I usually make a lot of animations in Friction with transparent
> background and mov file, and they don't work

A clip in Kdenlive may have transparency but unless you select a video codec and format that supports an alpha channel in the resulting video, any transparency will be rendered against a black background and appear black in the final video. I can imagine other applications working the same way. So, pay close attention to the render or export settings in Friction and choose a format that supports an alpha channel like ProRes 4444 or VP8 and VP9. The mlt format must be set to rgba, pixel format to bgra.

I am closing this bug report as RESOLVED-NOTABUG