Digital TV streaming
The Faculty of Arts has Satellite and Terrestrial TV 'rebroadcast' systems that put TV onto our network. Ordinary desktop computers can be setup to play these TV channels. This is the replacement for the old Cable TV system that was centred in the Language Centre in Brennan Building.
We have two different streaming systems currently in operation and there is some overlap between them, the older one is based on 'mpeg1' video and gives 'vcd' quality pictures. On a computer screen they look fine. The quality however isn't quite up to being projected.
The other system is based on the fact that TV transmissions are now digital. We have a trial system in place that takes 3 Sydney digital TV channels, and 4 Satellite channels and stream their programs onto the network with no processing of the video data in the middle, it is simply repackaged and transmitted out onto the network. This is MPEG2 video and is full 'broadcast quality' video. The picture on this system is identical to what you would see on your digital TV set at home.
These TV transmissions are available over much of the University network, however they do not leave the University network for copyright and technical reasons. You cannot watch these video streams from home, even over broadband (Which in general. in Australia, is no where near 'broad' enough for broadcast quality video!).
Not all sections of the University network (SydNet) are setup to transport multicast, so you may not be able to receive these transmissions. Talk to your local computer network person and ask that this feature be enabled. All Faculty of Arts network segments are enabled for multicast video. If you ARE the local computer person and are unsure, please feel free to give me a call.
NOTE: There is a known problem with VLC 0.9.x versions, they don't pickup all the SAP channels. We recommend downgrading to the VLC 0.8.x versions.
The VideoLan Client media player
The Video Lan Client program or vlc is a cross platform media player, that among it's features is the ability to take digital TV transmissions off the network and play them.
The Mac version differs in look from the Windows and Unix versions due to the different way OSX on the Mac works. However the function is the same.
For Faculty of Arts users, Mac and Windows installers for vlc are on Aristotle, Arts Public, All Software, (mac|windows), 'Not Supported'. We try to keep the latest versions of VLC here for ease of access. If you are not a member of the Faculty you will not be able access this server. Go to videolan.org and download the latest for your Operating System.
vlc can be used right away with out any configuration, however there are a couple of options in the player's preferences that should be set - it saves you from having to explicitly activate these options each time.
Setup SAP playlist
We need to bring up the 'Preferences' panel. On the Mac, you find this on the Application's menu 'vlc'. On other systems this is found under the 'settings' menu. Here there are subtle differences between systems with little triangle's to indicate submenu's or little '+' signs. You click on the triangle or the + to get the submenus to drop down.
The services discovery option SAP needs to be set as shown here.
Press the save button to save this in the application preferences.
What does this do ?. Our streaming software sends program announcement messages out onto the network on a special channel that contain the stream details. This is called the 'Session Announcement Protocol'. By listening for these SAP messages a software program can generate a guide of current programs available to by viewed automatically.
Setup deinterlaced video
This is quite optional - although the playback will look much better if you do set the 'deinterlace' options as (Standard Definition) broadcast television is transmitted in 'interlaced' format.
Note that for High Definition, some times the transmission is Progressive Scan instead. For this you want the de-interlacer turned off. Channel 7 is the only Australian broadcaster to use a 'progressive scan' format. The other channels use Interlaced format on High Definition as well. At this time no satelite broadcaster in the Asia-Pacific region is transmitting High Definition TV.
We head back into the Settings again, only this time we look for Filters under Video.
After selecting that we want to deinterlace we then need to select the type. So click on 'deinterlace' and more options appear.
Press the Save button, and you will be returned to the main controller window.
I've found that bob usually is the best option, however what is 'best' depends on your computer, type of screen and your perception of the effect.
You may have to restart vlc to see the effect.
Start the application. If it hasn't remembered that you want to view the play list, open the Play list Window.
Mac Window -> Playlist
Others View -> Playlist
The playlist window should look something like these
The MacOSX version shows the playlist attached to the bottom of the 'Controller'. The versions for other systems open a separate playlist window. Another note for Mac users is that you might get an error box that looks like this
Select the Suppress further errors check box and then dismiss the window. It is telling us it can't activate a particular feature our network doesn't support. VLC however works perfectly well with out this feature active.
Expand the 'Session Announcements (SAP)' section
Scroll through the list for interesting programmes. The standard interface conventions apply, click on the little arrow or the + to expand sub lists.
Our local streams all start with Usyd META or are in a subgroup called Usyd META
Most of the other programs you see in this playlist come from other places on the Internet. Most are not viewable - while their descriptions are available the actual program stream doesn't get to us, some do work.
You view a program by double clicking on a program of interest. Shortly after doing so you should get a window showing the program that looks something like this -
Note The playlist is dynamic, and will change by itself. As new sources advertise their presence, they will appear in this list, as they get turned off and old, they get removed. In this way, if we change the line up on our server, the program guide shown in the VLC playlist will also change.
Apple's Quicktime, version 5 and later can play the MPEG1 streams from a web page. Go to Satellite TV streaming to see what we stream in this format.
Other media Players
An other popular free media player called mplayer can also play all these streams, however it doesn't have a stream selection interface like vlc so has to be started with a command line with the appropriate URL of the stream. It does however work very well and in some cases manages better picture quality due to different playback algorithms.
RealPlayer can play the lower quality mpeg1 streams, however I've found it cannot reliably connect to the streams, more often than not saying it doesn't have the right plugins.
Windows Media Player
Windows Media Player can not connect to our network video streams with out a helper application, although it's quite capable of playing both mpeg1 and mpeg2 video if a helper application gets the streams off the network for it. (This is what Cisco's IP/TV client software does).
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