adrian@li137-80:~$ sudo apt-get remove ffmpeg
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package 'ffmpeg' is not installed, so not removed
0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
adrian@li137-80:~$ sudo apt-get purge ffmpeg
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
ffmpeg*
0 upgraded, 0 newly installed, 1 to remove and 1 not upgraded.
After this operation, 0 B of additional disk space will be used.
Do you want to continue? [Y/n] Y
(Reading database ... 70510 files and directories currently installed.)
Removing ffmpeg (7:2.8.8-0ubuntu0.16.04.1) ...
Purging configuration files for ffmpeg (7:2.8.8-0ubuntu0.16.04.1) ...
adrian@li137-80:~$ sudo apt-get install ffmpeg
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
ffmpeg : Depends: libavcodec57 (>= 7:3.2) but it is not going to be installed or
libavcodec-extra57 (>= 7:3.2) but it is not going to be installed
Depends: libavdevice57 (>= 7:3.2) but it is not going to be installed
Depends: libavfilter6 (>= 7:3.2) but it is not going to be installed or
libavfilter-extra6 (>= 7:3.2) but it is not going to be installed
Depends: libavformat57 (>= 7:3.2) but it is not going to be installed
Depends: libavresample3 (>= 7:3.2) but it is not going to be installed
Depends: libavutil55 (>= 7:3.2) but 7:3.2-0~16.04.york0 is to be installed
Depends: libpostproc54 (>= 7:3.2) but it is not going to be installed
Depends: libswresample2 (>= 7:3.2) but it is not going to be installed
Depends: libswscale4 (>= 7:3.2) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.