Delivering Live Content
With the appropriate license key, RealVideo Encoder
can deliver live content for broadcasting live events.
To deliver live content, you need:
- A live video source
- A computer running RealVideo Encoder
- A computer running RealServer
RealVideo Encoder and RealServer computers can be on different platforms.
To deliver live content using bandwidth negotiation,
use one computer for each bandwidth. Run the Live Encoder on each
computer connected to one RealServer. For more information on
bandwidth negotiation, refer to Managing Content on the
RealServer.
To enable live delivery, be sure the following configuration
settings are included in RealServer configuration file:
- PnaPort - the port number to which the Encoder connects
- EncoderPassword - the password the Encoder uses to connect
You have the option of specifying that the Server
saves the live content as a RealVideo file by setting the LiveFileTarget
and LiveFilePassword configuration option.
For more information on setting up RealServer, refer
to "Broadcasting Live" in the Server Administration
Guide.
If you want to advertise your live event, you can
list it in Timecast: RealMedia Guide (http://www.timecast.com),
The RealNetworks online resource for RealAudio and RealVideo
sites and live events. Thousands of people use Timecast to determine
what broadcasts are available. By listing your live event on Timecast,
you can greatly increase your audience.
Your listing appears in the Live Guide:
There are two ways to list your live events.
- Fill out a Web form with the relevant
information.
- Place special tags in your HTML
code.
Filling out a Web Form
Use the Web form (http://www.real.com/live/addlive.html)
if you have only a few events or programs that occur at the same
time each day, or each week. On the Web form, enter basic information
about the event, such as name, complete URL, date and time of
the event, and a short description. The data will be verified
and posted on Timecast.
Place Special Tags in your HTML Code
If you have several different events, you can save
time by inserting special "live tags" in your HTML code.
The live tags are placed within comment lines in the source HTML,
so that they are invisible to your users. A software robot reads
the information in the live tags and automatically enters the
event(s) in Timecast.
To advertise your live event using special tags:
- On the Web page with the link to your live event, insert the live tags using the following format:
<!--@Rastart event="Brief Event Description" start="Thu, 11 Apr 1996 20:30:00 EST" -->
(some HTML that describes the event)<!--@RAend-->
Note For more information about the live tag, refer to:
http://service.real.com/help/content/livetags.html
- Send e-mail to: live_event@real.com.
Do not enter a subject. In the body of the e-mail, enter the
complete URL for the page containing the live tags (for example:
http://www.real.com/example/tags.html). A software Robot gathers
the information in your live tags. The data will be verified and
posted on Timecast.
Note It is VERY important that you include the full address, including the
"http://" part. If you use frames, be sure to send the
address for the event page that appears within a frame, not the
HTML page that creates the frames.
Live encoding usually requires creating your own
template. How you design your template depends largely on the
power of your system. When encoding video frames that are 160
pixels by 120 pixels, a dual processor 200 MHz computer gives
a good result with a frame rate of 4 fps, Quality 100, or with
a frame rate of 9 fps, Quality 25. A single processor Pentium
system gives a better result when set at 2-3 fps.
For more information about creating templates, refer
to Creating Templates.
System Requirements for Delivering Live Content
The minimum system requirement for delivering live
content is a single processor 200 MHz Pentium. The recommended
system requirement is a dual processor 200 MHz Pentium Pro.
Producing High Quality Live Content
- The average bit rate should be higher
than the bit rate in the template. If the average bit rate is
lower, you will experience a deterioration in the video quality.
- Audio quality is important when delivering live content. Setting the volume too low can result
in a weak signal. Setting the volume too high can cause a distortion
of the audio.
- Under no circumstance is loss of audio acceptable. If you experience audio loss in a live broadcast,
lower the frame rate. If necessary, lower the video quality.
- Latency, the amount of time required
for buffering the video, should not exceed 5-10 seconds when delivering
live content.
- View the live content using a Web
browser. This allows you to see how the live content looks when
it is delivered.
RealVideo Encoder for Windows runs on Windows 95
and Windows NT.
To provide content in multiple compression algorithms,
run multiple machines using RealVideo Encoder with the same input
signal. All concurrently running copies of RealVideo Encoder should
use identical settings except for Compression Type. RealServer
uses bandwidth negotiation with RealPlayer to deliver the correct
content. Refer to Bandwidth Negotiation.
To encode and broadcast live content in Windows:
- Start RealVideo Encoder 1.0. RealVideo Encoder window opens.
- Click Open Session on the File menu. The Open Session window appears.
- In the source pane, click the Capture Device button.
- Click Audio Capture and Video Capture. Both audio and video must be captured together.
- In the destination pane, click RealServer checkbox, a check appears in the box.
- In the Host field, type the server name, IP address or machine name.
- In the Password field, type the password. This field is optional.
- In the Resource field, type the Web address of the broadcast destination.
- Click the OK button. The Open Session window closes.
- In the properties pane, enter the Title, Author,
and Copyright information for your output file. These fields are
optional.
- If you want to allow RealPlayer and RealPlayer
Plus users with low bandwidth modems to experience a RealVideo
broadcast encoded for a higher bandwidth by partially downloading
video data before beginning playback, click the PerfectPlay
checkbox.
- If you want to allow RealPlayer Plus users to
save your RealVideo signal to disk, click the Selective Record checkbox.
- In the templates pane, select the template to
encode the file. For more information, refer to Encoding
Templates.
Delivering live content usually requires that you
create your own template. Refer to Encoding Templates for
Delivering Live Content and Creating Templates.
- Select Statistics from View. The
Statistics window appears. The information displayed in this window
during broadcast will help you evaluate and adjust your template
settings.
- Click the Start button to start the encoding
process. The broadcast previews in the right window.
Note Preview can be turned off to marginally increase performance. From menu, click Options.
Click Show Filtered Output to clear the selection.
- Select Set Video Format from Options.
You can use this option to adjust video format settings while
delivering live content. Click the OK button to accept
the current settings.
- In the results pane of the Statistics window,
notice the Frame Rate. Wait while enough data is collected
for an average frame rate to be determined. If the average frame
rate is below the frame rate set in your template, adjust the
template setting to a lower frame rate.
- In the results pane, notice Latency. If latency
is greater than 5 or 10 seconds, adjust the template.
- View the live content in the preview window.
Viewing the live content through your Web browser is strongly
recommended.
Command line options allow automation of live feeds.
RealVideo Encoder options for live encoding are listed below:
| Option | Description
|
| /L | Turns on Live Input instead of static input file. The destination can then be selected between server or file output.
|
| /S server[:port]/filename | Specifies delivery to a server on the supplied port. If the port is not supplied then the default of 7070 is used. The server can be either a hostname or IP address. The filename is used as the target on the server.
|
| /W password | Specifies the password, if required to connect to the Live Server. The default is no password and is only used if the target is a server.
|
| /O | Used for the file name at the encoder if simultaneous file output is required.
|
| /I | Can be combined with the server details to enable slta functionality from the command line.
|
| /D hhh:mm:ss | Allows the encoder to run for the supplied time. The maximum time is 999:59:59. When the time elapses then the encoder should gracefully shutdown and exit. If a static file is being encoded and the file ends before the maximum duration, there is no need for an error message. If this option is not supplied, then the encoder continues to run.
|
Ctrl-C terminates encoding.
