rtmpGUI is a Windows application that uses RTMPDump, and comes with a updated maintained list of channels for you to stream from!! This list of live channels is HUGE! All the URLs and links are provided within the program! Download here - http://forum.wiziwig.eu/threads/58518-rtmpGUI-Offical-thread, video tutorial here
You cannot simply enter the "rtmpdump -r" code in Serviio
You MUST CHANGE THE PARAMETERS from RTMPDUMP to LIBRTMP parameters
If you want easy way to find Live streams without changing parameters, follow my XBMC Live Streams guide, this also has a rtmpGUI plugin
Serviio users took one step ahead of you having to change the parameters manually! Thankyou for your efforts!!
1. RSS livestream Folders
Thanks to the amazing efforts of jhb50, he has created maintained RSS livestream folders, you just copy the RSS feeds from this post into Serviio, make sure you have jhb50's livefeeds.groovy.zip available from the wiki, make you set Serviio to "RSS/Atom Feed"
2. User Chosen RSS Folder Solution
ragefuljoe made a brilliant filter that converts the xml rtmpGUI uses to an RSS folder in Serviio
Firstly go here - http://growing-flower-3635.herokuapp.com, choose the channels you want to view, copy the code to an rss file "LiveFeeds_YourTitle.rss" and host it locally or online, this also needs jhb50 livefeeds.groovy.zip, also make you set Serviio to "RSS/Atom Feed"
NOTE TO LINUX or NAS USERS
You MUST compile ffmpeg with librtmp enabled, without this some feeds will NOT work.
As a test, if you live in the UK, try the 4oD plugin, if those videos dont work then you've not installed ffmpeg with librtmp correctly