What's the difference between "streaming" video and "progressive download" video?
Streaming video arrives to the viewer in "real time", without the viewer having to wait for it to download somewhere on their computer before being able to view it.. A viewer can jump to different areas within the video at anytime. Also, streaming video dynamically adjusts to Internet conditions along the journey from server to viewer.
Progressive downloads are video files that must be downloaded somewhere on the viewer's computer in order to play. For high-speed Internet users (cable modem or DSL), the video will usually start playing as it's downloading, giving the viewer the illusion of streaming.
Can a viewer "save" a streaming video on their computer?
No. A streaming video, unlike a progressive download, cannot be saved on the viewer's computer. A viewer can save a link to the video, however embedding the player using javascript can prevent the viewer from doing that as well.
Does true streaming video require special servers?
Yes. Streaming video requires special server software that enables the server to actually communicate with the viewer's video player in order to determine what is the best speed in which to stream the video. A progressive download video file can be served from a standard web server.
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Can people with 56k dial-up modems watch streaming video?
Yes, but the viewing experience is, by necessity, usually of low quality. A streaming video optimized for 56k viewers should have a small viewing area (160x120 pixels), and a reduced frame rate (15 frames per second or less). A progressive download video for 56k users can be of higher quality, but requires a larger file that may require a long time to download.
Why are videos for 56k dial-up users usually so low quality?
In order to stream to 56k users, the video file must be kept as small as possible. An important rule of thumb: the higher the quality a video, the larger the file. In general, 56k phone lines don't handle large files well.
Should the 56k audience be ignored when it comes to streaming video?
Not at all; It's just important to design the video file specifically for 56k viewers. the RealVideo format from Real Networks is, by far, the most effective streaming technology for 56k viewers.
How many people now have broadband (high-speed) Internet access?
The latest figures indicate nearly 11 million households have broadband access. This represents 16% of all Internet users, a 50% increase from early 2001. Also, a significant percentage of businesses in America now have broadband access.
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How much better is the streaming video experience for broadband users than for 56k users?
Broadband users have a much higher capacity to receive large video files, therefore videos designed for broadband users should have larger viewing areas (at least 240x180), higher frame rates (up to 30 frames per second), and higher audio bit rates. No broadband user wants to have a 56k video experience.
Are there different Internet speeds across the broadband spectrum?
Most definitely. Some broadband users have single ISDN lines capable of no more than 64k. Other broadband users have lines ranging anywhere from 100k to 500k and above.
How do I reach the widest possible audience with the videos on my web site?
The best way is to create video files and associated links separately for 56k viewers and broadband viewers. By necessity, the 56k files would be smaller and of lower quality than the files created for broadband users. To reach the widest possible spectrum of broadband users, you can create separate files and links for different broadband speeds (100k, 250k, etc), or create multiple tracks within a single broadband file.
What is a multi-tracked video file for broadband viewers?
A characteristic of true streaming video is that multiple tracks can be created within a single multimedia file. Each track is encoded for a specific broadband speed (100k, 250k, 350k, etc). The video server will stream the appropriate track by communicating with the video player on the viewer's computer. The track that will stream will be based on the viewer's Internet connection speed and the general Internet conditions at the time of streaming. If there is an Internet slow-down while the track is streaming, the server will automatically stream a more appropriate track until there is less Internet congestion. This helps ensure a smooth streaming experience for the viewer.
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Can video files stream through corporate firewalls?
Yes, however changes in configurations of the player is sometimes necessary. For the RealVideo format, comprehensive information may be found at http://www.service.real.com/firewall/index.html.
Can video players be embedded into a web site?
Yes. While the viewer still has to have a player installed on their computer, custom elements can be created by the web site designer. Information on embedding the RealPlayer can be found by clicking here. You can find Information on embedding the QuickTime player by clicking here.
What is encoding and compression?
Encoding is the process of turning a video into digital code that can be streamed from and viewed on computers. Compression takes that code and shrinks into an appropriate file size for effective Internet streaming. Uncompressed code is normally in the .AVI format.
What are the most popular, and effective, streaming video formats?
There are three widely used formats. In order of popularity, they are: RealVideo, Windows Media, and QuickTime. Most people with Internet access usually have at least one, and often all, of the players necessary to view files in these formats. In general, RealVideo is the most effective format for true streaming, followed closely by Windows Media. QuickTime streaming presents problems for many viewers, particularly for PC users.
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What is the "basic rule of thumb" for creating streaming video files?
One thing that must always be kept in mind when creating video files from the original video source: The higher the quality of the streaming video, the larger the file size.
How can I create my own video files for upload to your servers?
The first thing you need are video and audio capture cards. Your VCR (or video camera) would connect to these cards via cables. Most computers have audio cards already, however you'll have to make sure you get the right cables to properly connect. A video capture card can easily be installed, however some video cameras will allow the use of a firewire connection. A popular, and affordable, video capture card, the Osprey-100, may be found on the Real Networks site at http://www.realnetworks.com/products/osprey/index.html. Typically, a capture card will create an uncompressed .AVI file. It is from this file format that you create a compressed file that is appropriate for Internet streaming.
What software programs are available for creating streaming video?
There are many different programs available for creating streaming video files. A few are free; a few are very expensive; most are somewhere in between; almost all are easy to use with a little practice. A popular encoder for the RealVideo format is the RealSystem Producer Plus found at the Real Networks site. Click here for more information. Windows Media files can be created using the free Windows Media Encoder. Learn more about the Windows encoder by clicking here. Apple offers a Quicktime player and encoder at their site. Click here for details. A very popular encoder for all three format, the "Cleaner 5", is available at Discreet.com. The Cleaner comes in a full version, and less expensive "EZ" version. Top-of-the-line professional encoders include the Macromedia Director, Adobe Premiere, and Apple's Final Cut Pro.
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What kind of camera is required to create streaming video?
Just about any camera can be used to create video that will look good on the Internet, however the Mini-DV or Digital 8 formats are probably superior since they already record in a digital format that transfers effectively into the various streaming formats. Importantly, the inherent limitations of Internet streaming dictate that investing a lot of resources into high production values for purposes of creating streaming video is not wise.
What streaming format produces the best quality video?
Although everyone has an opinion, independent studies show that the three most popular formats produce nearly identical viewing experiences when the parameters set at the time of encoding and compression are the same. In other words, quality depends far more on the variables the encoder has control over at the time of encoding than actual differences between the three most popular streaming formats.
What are the most important factors to consider when encoding and compressing video?
First, you have to decide what audience you want to reach: streaming video files for 56k viewers should be altogether different than streaming videos for broadband viewers. Secondly, you must decide whether to "stream" your videos in real time, or have the viewer download the files onto their computer. Third, you must decide whether to create files for broadband viewers that are multi-tracked, or if you want the viewer to select a link that most closely corresponds to their Internet connection speed. Finally, decisions must be made regarding formats and trade-offs: how high a quality experience you want your video viewers to have relative to the file size that you find tolerable.
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