What is Streaming Media ?Streaming media is basically concerned with allowing audio and video to be viewed on the web.
Well, you might say we have been doing that for years in the form of downloadable Quicklime, AVI or AVI files, where it is relatively easy to put a few minutes of video together and upload onto your site for visitor downloading.
However, there are a few drawbacks to this approach.
For the supplier there is there is a question of security, although in many cases the material will be freely distributable, any one who can gain access to the site can download and redistribute the file, which makes it difficult for companies who wish to receive payment for information or entertainment
Also the user has to download the file in its entirety before it can be viewed. With a 56K modem, this will take approximately 3 minutes per megabyte so, if the file was say 3 MB then it would take nearly 10 minutes to download, for what is probably about 1 minute of actual video footage.
To speed up the process surely we could start viewing the beginning of the video section that has already been downloaded and then by the time that had been viewed, the complete file would have been loaded and then we could watch to the end.
This is the essence of streaming. However in the above scenario it would hardly help.
In our example the video clip was 1 minute long and so, that we did not run out of material before we reached the end of the video we would have to download 9 minutes of data into a buffer before we could start viewing the file. In this case saving 1 minute in time is hardly worth it.
It would have been easier to go off for coffee whilst the whole file was downloaded.
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What Streaming Media doesStreaming allows the viewing of a video file long before the entire file has been downloaded. It makes it possible for people to see or listen to things almost as soon as they click on the link and then watch them for as long as they like - just like turning on the television or listening to the radio.
In this case the streaming server will keep topping up the memory buffer with the section of video you are just about to view until it has been completely viewed.
Downloading an AVI file (as the above example) is very much like taking a bath, you have to wait for it to fill up before you can take the plunge, Streaming Media on the other hand is like taking a shower, you can enjoy the experience immediately.
Another important point is the security aspect. As the streaming media file is normally downloaded only into a memory buffer and not onto the hard disk it cannot be copied - although some encoders give the supplier the choice to assign the file as a “stream only” or “save to disk” option. |
Why we need Streaming MediaThe short answer is because audio, and in particular video, use a huge amount of data
In fact downloading a single minute of a 4:2:0 standard television signal over a standard 56K modem would probably take over an hour and a half.
So, streaming media is used to make it possible to take a television signal and reduce the file size so it can be streamed over the internet for people to view.
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How Streaming Media worksThere are two things we need to do to stream media over the internet
First, we need to make the audio and video small enough to be able to deliver over a standard internet connection. This is carried out in the encoding process
Then, we have to take that encoded file and deliver it over the internet for viewing
So there are two processes that we have to look at Encoding and Delivery
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