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Video for the Internet Part I

Contributed By Glen Berry

Chances are that if you’re reading this article, you’re well aware of the limitations of Internet video. Most attempts to view video online are plagued with a slew of problems: jerky motion, artifacts, connection loss, tiny screen size, pixilated images, poor color reproduction and the ultimate killer: slow download times. All these problems are compromises made to get around that fact that the existing network technology simply isn’t fast enough to support the full-screen, full-resolution video that we expect from DVD, VHS, cable or satellite sources.

Why should one still attempt it? Because delivering video over the Internet is one of the most exciting possibilities for independent filmmakers to distribute their works. And although significant compromises need to be made, streaming video is possible with careful planning.

Before we get started with the planning of the project, we’ll need to define some terms. Whether you plan on outsourcing your web hosting to an ISP/caching service or setting up your own server, there are some key concepts that you should be aware of.

The Client/Server Relationship

Our objective is to make videos available on a website for visitors (also known as “clients”) to download and view. To do this, we can create a normal web page that contains a link, or URL, that the client can click on to request the movie file.

This website is running on a piece of software that we are going to call a “web server”, or simply “server”. The main purpose of the server is to fulfill requests made by clients. When a client clicks on the link described above, the server responds to that request by sending the client the appropriate movie file.

Upload vs. Download

When the server fulfills this request and begins sending the file to the client, the server is uploading the file. Conversely, the client is downloading the file from the server. This is a very important distinction to keep in mind when we begin planning to serve up video because our focus changes from requiring fast download speeds (the consumer perspective) from our network connection to requiring fast upload speeds (the video provider perspective).

Streaming Video

Since video files are so large, this upload/download transfer between server and client does not happen instantaneously. Once the transfer begins, the server continues to upload a continuous stream of data until the client has downloaded the entire file. Normally, in order to view a file on the server that entire object would need to be downloaded to your computer’s hard drive. However, one unique aspect of video files like Quicktime is that the movie can start playing using this stream of data before it is completely downloaded. This is called “streaming video” and requires a specially encoded file like Windows Media, Real or Apple's Quicktime.

Available Upload Speeds

Realistically, the type of connection that will suit the needs of the independent filmmaker setting up his or her own server would either be T-1 or DSL.

T-1 was the original mega-connection for those with mega-dollars. The cost of maintaining a T-1 can vary from $800-1500 depending on your location and ISP. Although many professionals still prefer this high-speed pipe, the maximum upload speed of 1.6 Mbps isn’t that much faster than the far cheaper DSL connections.

DSL comes in a dizzying array of flavors, including iDSL, aDSL and sDSL. Price for an sDSL line with 384 kbps upload speed can run from $120-250. Maximum upload speeds for DSL generally tops out at 1Mbps. The only important difference to keep your eye on is upload speed and price.

Cable was not included in this comparison list because cable connections generally have great download speeds but poor upload and rarely offer static IPs, a requirement for operating a web server.

How Good is Good?

Judging the quality of video is pretty subjective so I’ll just have to go out on a limb and tell you what the breakdowns are. A high quality video stream would take up 300kbps of network bandwidth, a medium quality stream would be 100kbps and a low quality stream would be 40kbps.

A Story Problem

You have decided that you can afford an sDSL line with an upload speed of 384 kbps. You want to offer the highest quality video possible to the greatest number of people you can. What are your options? 384 kbps line / 300 kbps video = 1 simultaneous user
384 kbps line / 100 kbps video = 3 simultaneous users
384 kbps line / 40 kbps video = 9 simultaneous users

Another Story Problem

If I decide that I want to offer 100 kbps medium quality video on a 384kbps sDSL line, how long will my 3 simultaneous users be tying up all my network bandwidth until the next person can view my great short film?

17 minute short film = network will be tied up for 17 minutes
5 minute short film = network will be tied up for 5 minutes
2 minute short film = network will be tied up for 2 minutes

Clearly, low network bandwidth is an issue that filmmakers must contend with when delivering video on the web. In next month's column, we'll discuss the various formats available for compressing video for the web and strategies on how to get your file sizes down without drastically compromising video quality.

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