These are some links to high definition multicasts. These are 20-25
Mbps streams, and require multicast to work. To see if your
connection is multicast-enabled, use the multicast tester at Multicast Technologies.
To use links below:
- Install VideoLAN (before you start the download, look for the University of Wisconsin-Madison mirror for fastest download).
- Click on a link below. The first time you do this, your computer
will not know how to display files with the extension VLC, and will ask
you. Browse to the VLC application, and choose it.
- Unicast versus IP multicast
- With unicast, one stream leaves the server for each viewer.
Unicast connections work on-campus and off-campus, over DSL and
cablemodems.
- With multicast, one stream leaves the server no matter how many
viewers. Multicast connections only work on the campus and at
other universities or institutions with advanced networks. DSL
and cablemodems do not support multicast.
- Multicast only works on wired connections.
- Multicast DOES NOT WORK
- on WiFi or wireless connections.
- on UW campus wireless.
- on DSL service.
- on cablemodem service.
- using WiscVPN.
- Global versus local scoping
- Multicast addresses starting with 239 are locally-scoped...That means that they stop at the UW-Madison campus border router and can not be seen elsewhere on the Internet.
- Multicast addresses starting with 233 are globally-scoped...That means that they can travel past our border router and across the Internet.
- Progressive scan, Interlacing and Deinterlacing
Interlacing is used to compress data. Half of the lines are sent
at a time, first the odd lines, then the even lines, and these
interlace with each other. When displaying video on an LCD
computer display, the lines are displayed in a progressive
(non-interlaced) way. When motion occurs with interlaced video,
some items on some lines appear in different locations, giving them
jagged edges. De-interlacing is a mechanism to reduce the
visibility of these jagged edges. VideoLAN has several settings
for Deinterlace, which can be found under the Video menu.
- University of Washington live (Mt. Rainier in the distance) [ udp://@233.0.73.26:1234 ]
- University of Wisconsin-Madison live aquarium [ udp://@233.0.59.6:1234 ]
- There is a 4 Mbps Multicast version of this stream at [ udp://@233.0.59.8:1234 ]
- There is a 1 Mbps Unicast version of this stream at [ http://128.104.23.100:8090 ] (Uses VLC)
unicast works anywhere-cablemodem, DSL, WiFi, off-campus.
Both of these streams will carry DART presentation at 7:00 PM on January 29, 2008
- University of Wisconsin-Madison recorded Marching Band [ udp://@233.0.59.2:1234 ]
- Only on wired connections on the UW-Madison campus - there is a stream of the digital feed of WISC DT at [ udp://@239.1.1.22:1234 ]
- There are multiple programs in the digital feed:
- a high definition feed of WISC
- a standard definition feed of My Madison 14
- VideoLAN can choose the program with a pull-down menu
- On Windows computers, the program is chosen with the Navigation menu, then the Program item.
- On Apple computers, the program is chosen with the Playback menu, then the Program item.
Dave Devereaux-Weber
dave@doit.wisc.edu
13-March-2008