Video distribution software and a USB digital camera
This month, as part of my ongoing research into video solutions for the
Windows NT platform, I take a look at Microsoft's NetShow 3.0. NetShow is a full-featured product and promises to keep Progressive Networks on its toes. And because NT 5.0 Beta 2 supports Universal Serial Bus (USB) ports, I hooked up Eastman Kodak's USB-based DVC323 digital video camera and gave the camera a run for its money. Keep reading, and I'll tell you what you can expect when working with the new USB interface and the OS that isn't--yet.
NETSHOW 3.0
I like so many features in Microsoft's third version of NetShow, the
company's video broadcasting and distribution software, that I can't bring
myself to single out just one. On a level from 1 to 10, with 10 being virtually unattainable, I'd give NetShow 3.0 an 8.5.
NetShow 3.0 includes NetShow Services, a software suite Microsoft designed
for video distribution over the Internet or an intranet. NetShow Services
consists of two parts: a server component and a tools component. You install
each component separately. Depending on how many clients you serve and the
performance you desire, you might not want to put NetShow's server components
and tools on the same system.
The server component contains all the utilities and documentation necessary
to distribute content over a variety of networks in different ways, depending
upon available bandwidth and desired performance. The tools component includes
three utilities for producing and editing content: NetShow Encoder, NetShow
T.A.G. Author, and NetShow Indexer.
NetShow Encoder is a powerful tool for capturing, compressing, and
converting multimedia data to a format acceptable for NetShow streams. NetShow
streams use Microsoft's proprietary Advanced Streaming Format (ASF) codec.
NetShow T.A.G. Author and NetShow Indexer edit and organize content (an Adobe
Premiere plug-in lets you save the content you created or edited as an .asf
file). Currently, you can view an .asf file's content only by using Microsoft's
freely distributed Windows Media Player.
The ASF codec offers variations that let you tailor your stream to the
content and bandwidth with which you are working. Depending on the quality of
video and audio you want, the amount of motion in the video, whether you include
slides, and how the majority of your client systems will view the content (i.e.,
via Internet or intranet), you can choose from up to 28 ASF variations. If
you're not sure which codec variation is best for your needs, the NetShow setup
wizard includes detailed dialog boxes that explain the advantages of each
format.
Installing the NetShow software wasn't difficult. Configuring the software,
although a complicated task, wasn't too difficult either, thanks to superb
documentation and wizards that worked so easily and quickly they gave me
whiplash. As with most new Microsoft products, you must have or install Internet
Explorer (IE) 4.01 to run the NetShow software.
When you open the server-based NetShow Administrator window, a list of
possible operations displays. Selecting any operation (e.g., Start Here,
Configure Server, Monitor Server) calls a list of options and features,
including various Quick Start wizards with integrated descriptions of the
features and options available when you configure content for network
delivery. For example, selecting the Start Here option initializes a guided text
tour. The opening text block runs through a brief introduction to the software,
defines key terms, and provides links to appropriate wizards. Selecting the
Configure Server option, as Screen 1 shows, gives you the information you need
to completely configure a NetShow server to transmit content across a network.
Selecting Monitor Server enables tracking of the activity of NetShow servers and
clients through an event log.
The first step in implementing a video distribution solution for your
network is deciding whether you want to deliver the content by unicast or
multicast. In unicasting, a server broadcasts one stream of content to one
viewer. Unicast streams usually let viewers pause, rewind, or fast-forward the
stream. NetShow delivers unicast streams from a folder on the server called a
publishing point.
In multicasting, a server broadcasts one stream of content to a station,
and multiple viewers can pick up the stream from the station. A station is a
file on the server that contains the location of ASF content. Because
multicasting transmits only one outgoing source stream that multicast-enabled
routers replicate across the network, multicasting uses much less bandwidth than
unicasting uses and reaches a larger audience. Because multicasts are available
to all network viewers simultaneously, one viewer can't control the stream's
progression. Multicast is best suited for live content and can also present
prerecorded material that many viewers access at the same time, such as a CEO's
address to stockholders.
Whether you choose to unicast or multicast your video content using
NetShow, a wizard exists to help with setup and configuration. The NetShow
Administrator server configuration interface includes Unicast Publishing Points,
Multicast Stations, Multicast File Transfers, and Server Properties options.
Selecting any of the first three options activates corresponding wizards;
selecting Server Properties lets you enable security and authentication and set
limits on the number of concurrent connections, bandwidth utilization, and bit-rate transfer.
NetShow Administrator's wizards are exceptional in the high degree of
customization they make available to users. If you are unsure what a particular
selection will do, you can almost always access an onscreen explanation or a link to explanatory text. NetShow has the best-documented and most
flexible wizards I have seen in any software product to date.
Opening the Unicast Publishing Points wizard calls a screen displaying two
options: On-Demand Unicast Publishing Point and Broadcast Unicast Publishing
Point. When you select either of these options, you can create a new publishing
point or modify existing publishing points. When creating a new publishing
point, you must choose a source for your content from options such as NetShow
Encoder, Remote Publishing Point, or Remote Station.
I selected the NetShow Encoder option on my test network in the Windows
NT Magazine Lab. Using an Intergraph TDZ 2000 with a Winnov Videum video
capture card and a Toshiba MK-128 video camera, and a Compaq WS6000 and Intel's
ProShare video camera and video capture card, I had no trouble linking live
video streams to a publishing point on my Toshiba Tecra 780CDM server using the
NetShow wizards. In fact, the entire process took less than 5 minutes.
I didn't just create a link to the site: The wizards let me dictate exactly
what formats to produce the video connection in. My choices included the
following: create an .asx file that points to the ASF stream; create an .htm
file with an <HREF> tag that links to an .asx file; create an .htm file
containing <EMBED> and <OBJECT> tags for Windows Media Player (this
.htm file is compatible with standard browsers); and copy <HREF>, <OBJECT>,
and <EMBED> syntax to the Windows clipboard. I found the clipboard copying
ingenious. This functionality is exactly what I see most Web developers looking
for--the ability to quickly paste the video tag into whatever HTML editor they're using.
An .asx file (or ASF Stream Redirector--ASX--metafile) is
NetShow-specific. An .asx file is a redirector file that directs a browser or
Windows Media Player to the source of an ASF stream.
As much as I like NetShow, the product lacks an important capability:
distributing content between smart servers during off-peak network hours to
optimize performance and limit network traffic. Multimedia content requires efficient management tools. Fortunately, Microsoft engineers told me such
functionality will appear in a future NetShow release.