When i installed phonon4qt5-backend-vlc to replace the obsolescent gstreamer
backend, dragon player would play no videos. In the console the following
messages would show repeatedly:

[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4006700] chain filter error: Too high level of recursion (3)
[00007f97f4006020] main filter error: Failed to create video converter
[00007f97f4004f00] main scale error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4006020] chain filter error: Too high level of recursion (3)
[00007f97f4005ba0] main filter error: Failed to create video converter
[00007f97f4004f00] main scale error: Failed to create video converter
[00007f97cc001420] gl vout display error: parent window not available
[00007f97cc001420] fb vout display error: cannot get terminal mode
(Inappropriate ioctl for device)
[00007f97f403ff20] main video output error: video output creation failed
[00007f980c00a570] main decoder error: failed to create video output


Further testing shows that installing the `vlc` package additionally
(containing the VLC gui application) resolves the problem. The problem
reappears after removing just `vlc`, suggesting that a needed library is
contained in that very package.

Of course, a system library depending on an application with a .desktop file is
unacceptable — we are not Arch. Please fix this packaging issue.