Real
Audio/Video
Choose which
account type you have:
Standard
Special
Real
Audio/Video for Standard
accounts:
RealAudio is a real time
audio transmission/player system. A digital audio stream is
transmitted from the server over the internet to the
destination and played immediately, rather than being stored
to disk first and then played.
Each audio clip requires two
files: a metafile with extension .ram, and the digital audio
clip itself, with extension .ra. The .ram file holds one or
more lines of ASCII text, each of which references the .ra
file to be played when the .ram file is accessed by the
browser.
Entries in .ram files have
the form:
rtsp://yourmachinename.primary-server.net/your-domain/name-of-clip.ra
Note: "yourmachinename"
is the name of your machine. To find out your machine name,
go to yourdomain.com/faq.html. At the top you will find your
machine name.
Place your .ram and .ra files
in the realaudio subdirectory under your web directory.
.ram files must be uploaded
in ASCII mode while .ra files must be uploaded in BINARY
mode.
You may then access these
files at realaudio/file.ram under your www directory.
Important: In order to
use the G2 features such as multi-rate SureStream and Slide
Presentations (.smi), You must use rtsp:// in the .ram file.
The metafiles (.ram) must be uploaded in ASCII mode while
the clips (.ra or .rm) must be uploaded in BINARY mode.
Real
Audio/Video for Special
accounts:
There is no
server-side Real software installed on Special accounts,
however you are still able to stream Real Audio/Video files
using HTTP Streaming.
HTTP streaming is
an alternative approach to serving RealAudio and RealVideo
files on the Web without the added management requirements
and expense of server-side streaming software. Although this
techniques is not well-suited for high-volume sites serving
numerous simultaneous streams, many smaller Web sites can
benefit tremendously from this simple and inexpensive
approach.
Actually, it's
better than inexpensive, it's free.
That's because
it relies on HTTP (HyperText Transfer Protocol) which is
already used by all Web servers to store and transmit
ordinary text and graphics files on the Web. And from the
producer's point of view, there's no added effort because
RealAudio and RealVideo files prepared for use on an HTTP
server are identical to those used with a streaming media
server.
There are some
important differences however, between the capabilities of
HTTP and specialized server software such as RealNetworks'
RealSystem Server 8.
For example, you
can't automatically detect the user's modem speed using
HTTP. Instead, files optimized for each of the various
connection speeds must be made available for users to select
themselves. Also, the HTTP-based approach does not allow for
live streaming audio or video presentations because complete
files must be stored on the Web server before they can be
accessed. Finally, HTTP does not make efficient use of
server resources, and as a result doesn't perform well under
heavy server loads.
But for sites
serving no more than a handful of simultaneous streams at
any given time, this is a great way to add streaming audio
and video features to your Web site without incurring extra
costs.
Here are
instructions for preparing RealAudio or RealVideo files for
use on the Web.
- Copy your encoded files
(files with the .ra, .ram, .rm or .rpm extension) to
your World Wide Web server.
- Use a text editor (such as
Notepad or SimpleText) to create a metafile containing a
URL to your file. For example, the contents of your
metafile should be in the following form:
http://hostname/path, where hostname is the name of your
World Wide Web server. For example: www.real.com
- Save your metafile as a
text using a .ram file extension.
- In your HTML document,
reference the metafile in a hyperlink. For example:
<A HREF="filename.ram">
<A HREF="http://hostname/file.rm">
You can use relative or
complete paths. If you use complete paths, you must
include both the hostname and the complete path. For
example:
<A HREF="http://www.real.com/home/welcome.ram">
- When a user clicks on the
link, the streaming file(s) begin to download. The
RealPlayer begins playing after a few seconds; it does
not need to wait for the entire file to be downloaded.
With HTTP
streaming and the right encoding and optimization tools, any
Web developer has the ability to create and serve on-demand
real-time audio and video.
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