Streaming - Problems & Solutions to video streaming, live streaming, and the streamintroduction,streaming,video streaming,live streaming,stream |
Given a good network connection, streaming video works well although in many ways it is surprising that it works at all. The nature of the Internet and its use of IP means that a broadcast is competing with other data transmissions, and in general there is no way of guaranteeing sufficient bandwidth to ensure an uninterrupted broadcast without denying emails, gaming and such.
Proprietary high-end video conferencing systems usually use other network technologies which has a relatively low but guaranteed end to end bandwidth, or ATM which can be set up with channels with guaranteed Quality of Service (QoS). Bandwidth over the Internet is increasing rapidly but unfortunately demand seems to be keeping up with supply, so increasing bandwidth alone is unlikely to solve the problem. Various developments are taking place which should ultimately result in QoS being available over IP.
A more mundane, but nevertheless important, difficulty in our experience is that many users have trouble setting up their client machines to receive audio and video. A more fundamental problem in many educational establishments is that teaching rooms have frequently been set up without audio hardware. Where there are a large number of machines in one area it is generally necessary to use headphones.
Because "live" broadcasts are not really live but are typically delayed for around 30 seconds it is difficult to set up remote feedback. For example where an on-line lecture has been publicized in advance it would be beneficial to allow questions from the remote audience. One way to achieve this would be to set up a Web page so that people could type in their questions, which could then to relayed to the lecturer by another person in the room.
Many organizations have their networks protected with a firewall and, even if normal Web traffic is allowed, special provision may have to be made to allow access to the ports used to receive streaming video. The same applies when serving video to the Internet from inside a firewall. For example, our test audio stream at www.brainfartradio.com is distributed out port 8000 however to reach the net, a hole had to be punched in the firewall in a way to let audio out but keep the darkside from coming in. Much of that can be accomplished with "port forwarding" to allow a stream to escape the firewall at port 8000 while being originated from an entirely different port on our server. Be sure to re-enforce the hole with permissions.
Despite the problems, streaming has shown that it is practical to deliver multimedia broadcasts across wide area networks, providing the end user is connected to the network with a reasonably fast connection such as Ethernet, DSL or cable modem. We do not consider it feasible to use a dial-up modem connection to view full motion video streamed broadcasts. 284KB just does not fit well into a 56KB pipe.
Careful consideration should be given as to whether video is needed as part of a multimedia presentation. Although easy to produce, a continuous shot of someone talking direct to camera is technically demanding on bandwidth and probably adds relatively little to the presentation. In particular, when producing material for education and training a combination of slide shows, animation and recorded computer session together with a commentary is easier to deliver and in many cases more effective than full motion video.
