ffmpegX installation problem

[Tripper]

I tried installing ffmpegX but after I press install it gives me the following warning that I have taken a ppic of which you can see HERE

[Case]

“You Must Sign In to View This Album”

[Tripper]

Well I guess I'll just tell you what it says.

IT says:
Alex is not in the sudoers file. THis incident will bw reported.
postdrop: warning: unable to look up public/pickup:
No such file or directory

[major]

Check if your OSX account has administrator privileges. Possibly create another OSX account and install from there.

[Tripper]

I tried installing it from the administrator's account but it still gives me the same message