Videos with no audio track cause loading to hand and video to not play

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Play video with no audio track (confirmed via playing in vlc and the volume 
starting at 0%)

What is the expected output?
The video to play

What do you see instead?
black screen

The Operating system you are using (Linux, Windows etc)?

Linux
What version of WebcamStudio are you using?
0.72 build 571
What version of Java are you using?
1.7.0_65

Additional notes
I noticed it by running webcamstudio from terminal, playing a video with an 
audio track showed all the loadup lines, then it would say Start audio ... 
Start video ..., but videos with no audio print Start audio ... and just sits 
there, if i mute the audio which i guess stops it from trying to load audio the 
video does play, and i'd assume adding an audio track would work also. Possible 
solution is making it load video before audio? Otherwise i'm fine with the 
workaround.

Original issue reported on code.google.com by [email protected] on 11 Jan 2015 at 8:27