Failed to open vdpau backend - Nouveau

I'm using ArchLinux and when I run vlc or mplayer, I used to get the error Failed to open VDPAU backend libvdpau_nouveau.so: cannot open shared object file: No such file or directory This doesn't seem to cause any error as far as video playback is concerned, but I want to know the reason for this problem. I referred to this post in UbuntuForums and one of the suggestions to solve the problem was to install nouveau-fw. Looking at the installed files by the nouveau-fw package, I couldn't find libvdpau_nouveau.so at all in the list, but surprisingly mplayer stopped showing the error after installing the package. But vlc still continues to show the error. The only other solution given in the post was to install official nvidia drivers. I'm hoping to avoid this and just use the open-source drivers. Hoping someone can provide a solution to this.