Error in installing ERPnext on Ubuntu 14.04

Frappe Framework Bug
1

Hi! I was trying to install ERPnext by setting up frappe bench but was
unable to do so. I tried the Easy way and got the following error

W: Failed to fetch http://ppa.launchpad.net/libv4l/ppa/ubuntu/dists/trusty/main/binary-i386/Packages 404 Not Found

E: Some index files failed to download. They have been ignored, or old ones used instead.

Output of cat /etc/lsb-release is
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION=“Ubuntu 14.04.2 LTS”