Hi John,
There are a few things you can do.
1. Go to the preferences of the RTP protocol (Edit|Preferences..., select RTP 
from the protocol list). Enable the option "Try to decode RTP outside of 
conversations". This should show all RTP packets you have in your capture.
2. There are two ways to get RTP streams, the first one via "Statistics|VoIP 
calls". This shows you the signaling sessions in the capture, and allow you to 
decode and play the media streams.
The other one is via "Statistics|RTP|Show all streams". This shows all media 
streams, of which you can select one and hit "Analyze to analyze the data. Now 
you have the option to save the RTP payload into a raw or au file.
As you might have picked up from the RTP Statistics page is that this works for 
G711 media. Other types don't have a decoder, for several reasons.
Hope it helps,
Jaap
John Harris wrote:
Hello people,
ich will convert UDP packets to RTP packets... I can't find a tutorial which explains how to do it exactly...the wiki of Wireshark http://wiki.wireshark.org/RTP_statistics describes to do it with the rtptools, but it is not possible to install the rtptools from http://www.cs.columbia.edu/irt/software/rtptools/. There is written, that the rtptools for win32 have to be installed with visual studio but as I said it is not possible....
Has anydody experience regarding this issue ?