Created attachment 117160 [details] Test case showing the bug. SUMMARY Combining the "Freeze" effect with others does not work. STEPS TO REPRODUCE 1. Insert a video clip on the timeline. 2. Select the video clip on the timeline and add the "Freeze", "White Balance" and "Fade from Black" effects. 3. Set-up the "Freeze" effect to freeze the video clip. 4. Set the "Neutral Color" of the "White Balance" effect to some color (e.g. blue, to produce a visible change in the color of the video clip). 5. Set-up the "Fade from Black" (or "Fade to Black") effect. 6. Position the cursor of the timeline into the video clip. 7. The "Project Monitor" tab should show the video clip being affected by the effects (but it will not, due to the bug). OBSERVED RESULT If the "Freeze" is applied, and then the "White Balance" effect and next the "Fade from Black" (or "Fade to Black") effects are added, all those effects do not work. (However they work if the "Freeze" effect is removed.) EXPECTED RESULT The "Freeze", "White Balance" and "Fade from Black" effect should work, even if used together. SOFTWARE/OS VERSIONS Kdenlive Version: 18.12.0 (64 bit Linux, Debian) KDE Frameworks Version: 5.51.0 Qt Version: 5.11.2 (built against 5.11.2) MLT Version: 6.12.0 FFmpeg Version: 4.1 frei0r plugins Version: 1.6.1 ADDITIONAL INFORMATION The attached "testcase.tar.gz" archive contains the test case showing the bug (the files are meant to be used in the "/var/tmp" directory). The file "testcase.kdenlive" is the Kdenlive project file, referencing the file "testcase.mp4" (an example source video clip). The file "testcase-output.mp4" is the file produced by rendering the project file (showing the bug; without the bug it would show frozen image first fading in, next zooming in, then freezing again and fading out, being heavily orange tinted all the time).
Please try with the current Kdenlive_Nightly_Appimage https://binary-factory.kde.org/job/Kdenlive_Nightly_Appimage_Build/lastSuccessfulBuild/artifact/ I tested and it works as expected.
Created attachment 117256 [details] Backtrace of a crash when creating a new project
Created attachment 117257 [details] Backtrace of a crash during start up
Unfortunately, the nightly AppImage build (24a3010) crashes when creating a new project (see the attachment 117256 [details]) or when trying to load the test case. It also display the message "Could not create the video preview window. There is something wrong with your Kdenlive install or your driver settings, please fix it." during start up. I have also built Kdenlive (version 19.03.70) with MLT (version 6.13.0). It crashes during start up (see the attachment 117257 [details]), making it impossible to try the test case.
I have tried the test case in Kdenlive version 19.04.1 (with MLT version 6.16.0), and the bug is no longer present (i.e. the "Freeze", "White Balance" and "Fade from Black" effects work all together as expected).
Thanks for the feedback and contribution. Glad to hear it works. We close this bug. If it still appears in the latest version, please feel free to re-open it and update the affected version number.