video/3gpp no sound

Please install vlc and try to use it:

Open a Terminal from the menu Applications->Accessories->Terminal

Tip: right click with mouse on the terminal title caption and select the item "Always on Top" doing this you will force the terminal window to stay on top of the other windows and you will find very easy to copy single row from this web page into the terminal...
Something more about using the terminal https://help.ubuntu.com/community/UsingTheTerminal

Then type or better copy and paste a row a time then press enter:
(Tip: select the single row to copy then right click into the terminal and to quick paste click with middle button of mouse )

sudo apt-get update
sudo apt-get dist-upgrade
sudo apt-get install vlc

give your user password when requested, you don't see nothing when you type it, then press enter.

Hope this helps

i tried it, vlc gives me the followging error:

"
Geen bruikbare decodermodule:
VLC ondersteunt het "samr" audio- of videoformaat niet. Helaas kunt u dit niet oplossen.
"

rougly translated to english:

"
No usable decodermodule:
VLC does not suppord the "samr" audio or videoformat. u cannot solve this problem.
"

what should i do next?

Please read:

http://ubuntuforums.org/showthread.php?t=762399
https://bugs.launchpad.net/ubuntu/+source/ffmpeg/+bug/93849

Hope this helps

http://ubuntuforums.org/archive/index.php/t-1219403.html