Windows Media Encoder can be used in conjunction with
a Windows Media server to broadcast a live event. This gives an
organization the capability to use the Windows Media server as the
back-end server to publish the live content to multiple users. Also, a
laptop or some other mobile or portable device can then act as the
system capturing the video/audio content that will be published by the
Windows Media server.
Preparing for a Live Broadcast
To prepare for a live broadcast,
a Windows Server 2008 server or Windows Vista workstation with a
compatible camera and microphone, or a system with a video/audio capture
card, must be configured and tested for basic functionality. The camera
and audio devices should be able to capture and record video and audio
content at the desired level of quality.
After the remote system is working properly, the live broadcast can be initiated.
Initiating a Live Broadcast
To start a live
broadcast, Windows Media Encoder should be launched on the broadcasting
system. After being launched, follow these steps:
1. | Select Broadcast a New Event, and then click OK.
| 2. | Select the video and audio device source that will be capturing the event. Click Next when you are ready.
Note
For systems with only a single
video and audio source, the options should default to the only devices
in the system. However, for systems with an audio and video capture card
installed, the onboard audio might also be an option, so be certain
that the correct video and audio devices are selected.
When choosing the audio
device, you might want to click Configure and confirm that the
microphone has been enabled. Many systems automatically have the
microphone disabled, so although the correct device has been selected,
no sound will be captured.
| 3. | The
next setting allows the Windows Media Encoder system to either push the
video/audio stream to a Windows Media server on the network, or allows
the Windows Media server to initiate a pull from the encoder system.
Make the choice and then click Next to continue.
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Note
The
choice of whether to push or pull media content depends on what you are
closer to. If you are closest to the Windows Media Encoder system (you
are in the room where the event is taking place), you probably want to
push the video/audio stream to the Windows Media server. A push from the
encoder system causes the Windows Media server to automatically start
publishing the session.
If the Windows Media
Encoder system is set up in a room and you are with the server, but not
necessarily where the encoder system is located, you can initiate the
capture remotely by choosing to have the Windows Media server initiate
the session.
If you choose to push to the Windows Media server, you will be prompted with the following steps:
1. | You
will be prompted to enter the name of the Windows Media server and the
publishing point, and you have the option of copying the publishing
point settings from another configuration. Click Next when ready.
| 2. | The
next screen will prompt for the encoding options. The various bit rates
for encoding will be shown, displaying Total Bit Rate, Frame Rate, and
Output Size. Choose the desired bit rate or bit rates, and then click
Next to continue.
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When given the option of
choosing the bit rate or bit rates supported, keep in mind the quality
desired as well as the bandwidth available to publish the media files.
If users are dialing in to
receive the published content, you do not want a total bit rate that
exceeds the available bandwidth of the dial-up modem session. Just
because a user has a 56KB modem does not mean that user is getting a
56KB bit-rate speed. You should choose a bit rate lower than the
available bandwidth.
Multiple bit rates can be
selected for the encoding options so that a modem rate (possibly 24Kbps
or 37Kbps), a DSL/cable modem rate (possibly 135Kbps or 240Kbps), or
high-quality rate (possibly 500Kbps or greater) can be selected. With
multiple bit rates, the bit rate that meets the transmission speed of
the remote client system will be used. Therefore, a user coming in over
DSL might get a 135Kbps transmission, and a user coming in over a
dial-up modem might get the same transmission at 24Kbps.
When selecting multiple bit
rates, one thing to consider is the size of the captured file. The more
bit rates that are selected, the larger the file will be. Each bit-rate
encoding option selected will capture a video and audio stream for that
mode. So if 12 bit-rate encoding options are selected, 12 streams of the
content will be stored in the file.
Another point to consider is the
desired available bandwidth. Even if all the users have high-speed
network connections and can accept a 768Kbps bit-rate encoded stream, if
the file is published using unicast broadcasting, a network might
become oversaturated with too much data. A lower captured video stream
can allow more users access to the information.
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| 3. | For
live broadcasts, an archive copy of the broadcast file can be captured
and saved to disk. This allows for future playback of the session.
Select the check box to archive the file and enter a filename to capture
the session. Click Next to continue.
| 4. | Information
can be added to the broadcast file, such as title, author, copyright
information, rating, and description. This information is optional.
Enter the desired information and click Next to continue.
| 5. | The
next screen gives you the option to begin the broadcast when the Finish
button is clicked, or to simply finish the configuration and start the
session later. Make the appropriate selection and click Finish.
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If you choose to pull where
the session is initiated by the Windows Media server from the encoder,
you will be prompted with the following steps:
1. | You
will be prompted to enter a free HTTP port that can be used to
communicate between the Windows Media server and the Windows Media
Encoder system. Port 8080 is the default, but by clicking the Find Free
Port button, you can search for an open port. Click Next to continue.
| 2. | The
next screen prompts you for the encoding options. The various bit rates
for encoding will be shown, displaying Total Bit Rate, Frame Rate, and
Output Size. Choose the desired bit rate or bit rates. Refer to the
“Choosing the Bit Rate(s)” sidebar for more details. Click Next to
continue.
| 3. | For
live broadcasts, an archive copy of the broadcast file can be captured
and saved to disk. This allows for future playback of the session.
Select the check box to archive the file and enter a filename to capture
the session. Click Next to continue.
| 4. | Information
can be added to the broadcast file, such as title, author, copyright
information, rating, and description. This information is optional.
Enter the desired information and click Next to continue.
| 5. | The
next screen gives you the option to begin the broadcast when the Finish
button is clicked, or to simply finish the configuration and start the
session later. Make the appropriate selection and click Finish.
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For live broadcasts, it’s
usually preferable to test the broadcast process to make sure that the
lighting, sound quality, and video quality are at the desired level.
Playing around with the different bit rates can provide better results
based on the needs of the organization. Although a producer can choose a
higher bit rate to get better quality, the results might not be better
than those obtained at a lower bit rate and with presumably
lower-quality published media. If the lower bit rate produces results
that are still acceptable, lowering the bit rate can minimize bandwidth
demands on the network, creating less demand on the network and allowing
the organization to have more simultaneous media streams.
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