Recently I came across this gstreamer error, claiming missing a codec under the handle »meta/x-gst-fourcc-rtmd«. I have not looked into the codec further, as I believe this is already a recognized bug and will probably be taken care of at some point in the far future. Also, this dirty fix did it for me.

Change settings in VLC to get rid of »meta/x-gst-fourcc-rtmd« error

But in case you want to quick and dirty »fix« this right now, here is how to do it in VLC Player:

1. Go to Tools → Preferences → Video
2. Set Output to X11 video output (XCB)

Also:

1. Go to Tools → Preferences → Input/Codecs
2. Select Hardware-accelerated decoding: Disabled

After making these changes I was able to play my videos nicely. I had this issue with mp4 files from my Sony Alpha 6600 camera. Hope this helps!

No option for Parole, but let me know if you find the real solution!

I didn’t even notice that this produced a codec error, since VLC just crashed when I tried to play an MP3 file. I found out by coincidence from this error in parole. However, in parole, setting the standard output to X11 didn’t do anything for me, so for now I removed parole from Debian altogether, since it’s a crappy player anyway and I never use it. But if you come across a better (real!) solution, please let me know. I’d love to get this fixed properly, I simply don’t have the time to go down some library rabbit hole right now.