Widevine have to provide libwidevinecdm.so in /usr/lib/qt6/plugins/ppapi/ so Falkon and other browsers to use drm content. The easier way, about me is https://dl.google.com/widevine-cdm/versions.txt provides versions they work with all chromium based browser, just for Qt is needed to have link in plugins.
https://dl.google.com/widevine-cdm/${version-from-link-above}-linux-x64.zip
Makes no sense to start downloading a separate widevine, current in chrome is 4.10.2710.0, so on the supported list.
To make it works with all browsers, it certainly can't be just in a qt6 directory. AFAIK, it still should be in the /usr/lib/chromium directory to be seen/used by most, might be needed to add an extra link for Falkon, but you can test that yourself too., just add the link.
I test with version in build, but symlink is incorrect it point out to:
/opt/google/chrome-unstable/libwidevinecdm.so
But it should point to:
/opt/google/chrome-unstable/WidevineCdm/_platform_specific/linux_x64/libwidevinecdm.so
/usr/lib/chromium/libwidevinecdm.so is incorrect too.
