Streaming media:

Media on the web
There are many different formats for playing digitized audio and video materials through your computer, and many are useful in incorporating these features into web pages. The critical issue in most cases is load time. There are two situations:

A short presentation will often be downloaded in an appropriate format along with the page and then played, either on demand or when the page loads. There are many uses for such methods, especially where the visitor desires to have the video material permanently for future replay. The major disadvantage is that audio, and especially video, files of any length are very large and the user must wait for the entire file to download before it begins to play

For a longer musical score or video presentation the best approach is to use a streaming format.The result is like listening to a radio broadcast. It can begin quickly regardless of the actual total length, and it can play indefinitely without filling up your computer. Streaming video is a bit like a TV broadcast in that it begins playing as soon as the first frames arrive, is not saved on the user’s machine, and can thus be of indefinite length. In fact, streaming video is usually used for live TV broadcasts over the web.

In this case the material is stored in a very large file on the server. However, instead of downloading and then playing the entire file, only a short initial section is loaded to provide a buffer which allows you to play on through short variations in network speed. The material is then played from the buffer while the remainder of the material continues to download.

Advanced streaming technologies will allow you to synchronize audio and video streams to create commented slide show presentations, to broadcast live audio and video presentations, and to tailor size and resolution of images and quality of sound to the user's connection speed, and even to the current state of internet traffic.

True streaming video is available in several formats but today the one with the most likelihood (93%) of being available on the user’s machine is Flash, with Realmedia being another strong contender. Other video formats can be converted to Flash or Realmedia formats, and we can provide flash interfaces that will stream formats such as MP3. Streaming video can adapt to the user’s connection speed by sensing it and adjusting the resolution of the video presented. These properties make it well-suited to playing video clips in on-line marketing, newsbites, help screens, and many other applications.

On the negative side, true streaming video requires special hosting which must license server technology and is costly and usually charges for connectivity on a bandwidth usage basis. In the case of Flash this is a Flashcomm server. The need for special servers can be eliminated by renting hosting for just the video on a site designed for the purpose and linking it from there into your site. These kinds of solutions are appropriate for sites that have delivery of media as a principal purpose. One such host is Vitalstream Flashcomm streaming video service, http://www.adobe.com/products/flashcom/fvss which charges from $300 to $2000/month depending on transfer and storage requirements.

There is an intermediate solution called “progressive video.” Like true streaming video, progressive video begins playing as the first frames arrive. If done as a Flash-format movie it will work in any browser in which Flash will work, and will appear as an ordinary embedded movie. Unlike true streaming video, progressive video does not require any special server, and is inexpensive to deploy.

The principal drawback is that it does not adjust resolution to match the connection speed of the user. However, with intelligent planning of screen-size and design for a 56k modem at decent resolution, such movies can be very acceptable at any connection speed, especially with good optimization. The examples on this page are done using such a technology.