For WebRTC error code descriptions see this part of the wiki (
https://code.google.com/p/bigbluebutton/wiki/090InstallationUbuntu#Client_WebRTC_Error_Codes). A 1002 error can also be caused by an improperly configured server. Try running the following command to make sure that your config files are set correctly, "
sudo bbb-conf --enablewebrtc". The actual cause of the 1004 is contained in the browser log so you can either search through it for the section that contains the 'fail' or copy it to pastebin and I can look for the cause.
I would also suggest trying to connect to
demo.bigbluebutton.org from the same computer and if it works fine then you can exclude the client from being the problem.