Some times you may get an error in FFMPEG Shared Libraries not Found while installing on your system,
checking whether to force gd support in ffmpeg-php... no
checking for ffmpeg headers... ...found in /usr/local/include/libavcodec
checking for ffmpeg libavcodec.so...
configure: error: ffmpeg shared libraries not found. Make sure ffmpeg is compiled as shared libraries using the --enable-shared option
Execute the below commands,