Media Playback Error: Failed to initialize Xv output

I found a simple media player on github: https://github.com/wxWidgets/wxWidgets/blob/master/samples/mediaplayer/mediaplayer.cpp

I copied it to a new project and ran. Everything seemed to go well until I tried to open the .mp3 file. I got this error:"Media Playback error. Could not initialize Xv output".

I am working on Ubuntu in a virtual machine, so I thought maybe I was missing something. I opened Rhythmbox

and tried to reproduce the same file and I got the same error. I searched on Google and found this:

https://askubuntu.com/questions/750418/my-rhythmbox-not-playing-mp3

I installed the gstreamer plugins-ugly

and plugins-bad

, ubuntu-restricted-extra

. Also, I installed libxv-dev

because I thought it had something to do with all of this. It didn't work. I reinstalled Rhythmbox

and now it works fine. I thought I solved the code (media player) problem, but didn't. I am still getting the same error.

How can I get this to work? And why am I getting this error in the first place?

I forgot to mention. I also get these messages: