HINTS FOR VIEWING VIDEO ON THE WEB
(This discussion is limited to the Windows OS)

Formats | Players | Playing | Streaming | Browser Issues | Choosing a Player

Video files, by definition, tend to be very large, because they include many individual images displayed in sequence to create motion, and usually include an audio track as well. Video files used on the web are therefore limited in resolution (320x240 pixels) and are highly compressed in order to minimize file size and speed loading.

FORMATS

There are several methods of creating this file compression by using a special protocol (algorithm or codec):

• MPEG - (Moving Picture Experts Group) This is an ISO standard compression system using the .mpg file extension .
• AVI - The .avi format was developed by Microsoft for Windows, and does not require any special hardware, but does require special software to produce.
• MOV - A .mov extension denotes a QuickTime compression method developed by Apple Computer for the Mac OS. There is also a Windows version of QuickTime.
• ASF - The Advanced System Format (.asf) is used by Microsoft Windows Media, and requires special software to produce and read.

Of these, MPG is the most universal, cross-platform system and is therefore the system used on this site.

MEDIA PLAYERS

Playing compressed video requires a media player that includes the codec for the media type being used. There are many freeware and shareware media players available for download, and all include support for all media types. Some of the most popular include:

• Windows Media Player - A full-featured player that is included with Windows software and updated versions are also downloadable here.
• Nero - A commercial product available here.
• RealPlayer - A commercial product, but with a free version available here.
• QuickTime - A full-featured, free download available here.

PLAYING VIDEOS

Normally, playing a web video file means first downloading it to a temporary file on your computer and then invoking the media player to execute it. Since even compressed files can be very large, this can mean significant wait times for the download, especially at dial-up transfer rates. But, rather than wait for the complete file to download, it is possible for the file to begin playing immediately, while the rest of the file is loading. This is known as...

STREAMING VIDEO

There are essentially three ways to stream video. All of these have to do with the way the client (media player) handles the file, regardless of the source server.

• Buffering - A portion of the file is held in memory and begins playing while the rest of the file downloads. If your computer is capable enough (sufficient CPU speed, memory, and cache space), this provides smooth viewing; if not, there may be momentary glitches as buffer memory is replenished, or significant waits while more data is received.
• Segmented Buffering - This scheme gets around inadequate PC resources by breaking up the file into small chunks; one is received, buffered, and played while the next is downloaded, and so-on, avoiding buffer underruns. The segment strings, however, require a media player that can accept them.
• Proprietary Protocols - This is essentially segmented buffering, but uses a proprietary special-purpose protocol that can only be read by certain players. RealPlayer uses such a system; hence, Real video can only be viewed on RealPlayer, though it can also read other protocols.

BROWSER ISSUES

Microsoft Internet Explorer - While still the choice of 75% of internet users, it has some shortcomings. It does not support streaming of mpg files; therefore the download must be completed before being handed off to whatever media player is used; this means potentially long wait times. IE is also notorious for its security holes and constant patches.

Mozilla FireFox - Is a much better choice. It is freeware, downloadable here, and looks and feels much like IE. But it has many superior features. Most notably, it is much more secure. It does support streaming, with any media player that also supports it, and can display the video in the browser, rather than opening the player separately. Another very helpful feature is that you can right-click a video link and reach a number of handy options, including opening the link in a new window/tab, bookmarking links, and saving the linked video to your drive without downloading/playing it first. (Additionally, you can easily import your IE favorites, history, and passwords, with a single click.)

CHOOSING YOUR PLAYER

As mentioned above, there are many, many media players out there. The essential criteria is that your player supports streaming media, and not all do. RealPlayer, for example, supports streaming for its own proprietary Real video, but not for other formats, and so is not a good choice. The best choice for overall robustness and full featured support for video and other media is the QuickTime Windows Version.
If you have multiple media players on your PC, it's a good idea to specify a default player for .mpg files, so that the optimum player will be invoked when a .mpg file is downloaded. To do this, use Windows Explorer to locate a .mpg file on your computer. Right- click the filename and click "Open with...". Even if you see your player in the list, don't select it -- select instead "Choose Program..." In the dialog that opens, select your player and then be sure to check the box "Always Use the Selected Program..."

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