Sometimes, it may be necessary or desirable to process Kdenlive project files using XML tools. Some of these tools, such as the Firefox browser as well as all libxml2-based tools, cannot process some, but not all, Kdenlive XML project files. As it turns out, sometimes Kdenlive projects contain an attribute kdenlive:customeffects. However, the project document lacks any declaration of the namespace kdenlive. In turn, these files won't be processed by XML tools, but instead turned down.

To allow correct processing of such project files, it will be sufficient that Kdenlive generates a proper namespace declaration in some suitable place (opening mlt tag), such as:

<mlt ... xmlns:kdenlive="http://www.kdenlive.org/" ...>

Also, I see both an attribute as well as a property element both for custom effects using the same namespace and same name. Which one of the two is the real one? What if both differ? What if only one is present?

Reproducible: Always