Kdenlive/Development

Kdenlive is rather easy to build (at least on supported platforms), and this page should show you the simple steps to get there. If you encounter any problem during the process or spot any information that should be added/updated, please don't hesitate to reach out to the Developer's mailing list, on the Telegram Kdenlive Developers' group or the Developers' Matrix room.

Building Instructions

The building instructions have been moved to the dev-docs folder in the code tree.

(the rest of this page should follow)

Next Steps

Once you've got a working dev environment, you should checkout the Contributing Guide and Coding Guide.

Now you can tasks find some nice first issues to solve. Welcome on board!

A instruction of the workflow with KDE's GitLab can be found here. You can also gain more general knowledge by exploring the tutorials on TechBase.

IDE Setup

Pick your favourite!

Setting up KDevelop

Open KDevelop and go to Project > Open/Import project Then select the CMakeLists.txt file in the kdenlive source folder. You can now start hacking on Kdenlive!

Setting up QtCreator

After checking out Kdenlive from git—when working on refactoring, you may want to clone two copies, one with the next branch and another one on the refactoring branch—, you can open the CMakeLists.txt in QtCreator, which will load the project if cmake succeeds. If you run/debug Kdenlive, make sure that kdenlive and not kdenlive_render is selected as an active project.

If you let QtCreator restore the previous session (File → Session manager), it will remember the open documents. Environment variables (see below) can be set in Projects > Build Environment.

If you genearated a kdenlive.qch file, you can add it to Qt Creator with Tools → Options → Help → Documentation → Add

MLT documentation

Kdenlive uses MLT’s C++ API called mlt++. This API is not documented as it is simply a wrapper to C functions. For example, the documentation of Mlt::Consumer::position() can be found in framework/mlt_consumer.c:mlt_consumer_position(). The actual C function name is usually a combination of the class name and the function name, but can also be found by consulting mlt++/MltConsumer.cpp:position().

Environment variables

If kdenlive crashes on startup (e.g. in QtCreator) and shows a message like:

   kdenlive(24309) KXMLGUIClient::setXMLFile: cannot find .rc file "kdenliveui.rc" for component "kdenlive"

then you have to ensure the .rc file is found. If CMake is configured to install Kdenlive to /usr/local, the .rc file is put there, but when kdenlive is then run from the build directory, the KXMLGUIClient will not search there. Solution: Set the environment variable KDEDIRS to $KDEDIRS:/usr/local.

You can get more information about the paths that are checked by running kdenlive like this:

   strace build/src/kdenlive 2>&1 | grep kdenliveui.rc

Wayland

To avoid flickering here are some Kdenlive envvars that work with Sway?

QT_QPA_PLATFORM=wayland-egl
SDL_VIDEODRIVER=wayland
XDG_SESSION_TYPE=wayland

Kdenlives File Format

A description on Kdenlives file format can be found at [[1]]

Contact

See Contact