vlc - not playing back opus file created by the demo in the opus lib

on ubuntu 12.04 did an apt update / upgrade and only got to vlc 2.0.3

rob@ ~$ cvlc -v
VLC media player 2.0.3 Twoflower (revision 2.0.2-93-g77aa89e)
[0x1f47108] main libvlc warning: This doesn't look like a valid plugins cache
[0x1f7e758] dummy interface: using the dummy interface module...

It throws all kinds of errors playing back an opus file created with the opus lib 1.1.1 ...

[0x1ecd108] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing
[mp3 @ 0x7faddcc115a0] Header missing


rob@ opus$ ./opus_demo -e voip 48000 1 120000  /home/rob/133041.wav ../myopus.opus

libopus 1.1.1-beta
Encoding 48000 Hz input at 120.000 kb/s in auto mode with 960-sample frames.
average bitrate:             147.403 kb/s
maximum bitrate:             240.400 kb/s
active bitrate:              154.607 kb/s
bitrate standard deviation:   42.169 kb/s

'myopus.opus' wont playback on the vlc UI client ( 2.0.8)

i can select the file from the directory viewer and hit play but nothing happens.

Not sure how to playback the test files being created with the opus demo ??