FYI: (solved) Ubuntu 16.04LTS codec missing package needs to be installed to use ffmpeg

[Harald Albrecht]

The sudden crashes I asked for help with on Ubuntu 16.04 are actually 
caused by a missing extra codec package. I've just found out by pure 
coincidence.

So, please make sure to install libavcodec-ffmpeg-extra56 on Ubuntu 
16.04, which isn’t installed by default. Without it, all video 
applications crash that make use of ffmpeg, such as VLC, SMPlayer, and 
others. This is a Ubuntu issue, not a Kdenlive issue.

Best regards,
Harald