无法安装ffmpeg-无法纠正问题,您持有损坏的包装

我想安装ffmpeg,但收到以下消息。我怎样才能解决这个问题 ?

(base) h@cheemc52:~/opencv/build$ 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: libavcodec56 (>= 10:2.6.9) but it is not going to be installed
          Depends: libavdevice56 (>= 10:2.6.9) but it is not going to be installed
          Depends: libavfilter5 (>= 10:2.6.9) but it is not going to be installed
          Depends: libavformat56 (>= 10:2.6.9) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.