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How to Add Streamed Real Audio® Files to Web Pages


There are three main techniques for adding sound or audio files to web pages:

This page describes how to add simple streamed Real Audio® files to web pages. It concentrates on Microsoft Windows® type PCs, but audio software is available for most types of computers. Many embellishments are possible: This page describes the simplest way of adding streamed audio.

For background information see: Overview: Adding Audio to Web Pages.

To stream MP3 Audio see: Adding Streamed MP3 Audio Files to Web Pages.


Disclaimer

This information is supplied "as is". Neither Curlew Communications Limited nor the author take responsibility for any loss or damage caused by use of the information.


Why Use Streamed Audio Files?

Streaming is useful when the audio file will be replayed only once and is short enough to be replayed while the web visitor is online.

Perhaps you do not want people to download and store copyright files or files which may soon become obsolete? However, note that determined users can record anything they find on the Internet, so simply streaming an audio file will not protect it from being copied. Streaming is especially useful when you want web visitors to remain viewing your web page while replaying your short audio files.

Real Audio® is the best known format, with several million active users. The BBC web site is a major source of audio and video in Real Audio® and Real Video® format.

Recently, MP3 has become very popular. Files can be replayed by several hardware devices as well as many software players.

Microsoft offers a different format which is replayed via the Microsoft Media Player® software. In future, Microsoft software may achieve dominance.

Popular software players include:

For heavy traffic, the host web site needs to run a special audio server application. However, the ordinary (http) web server can supply occasional streamed audio to one or two simultaneous users.


Step 1 - Prepare the Audio

Any live or recorded material can be used - but be careful of copyrighted material. The better the material, the better the results. If possible, edit the material to trim unwanted sections and equalise the audio levels. Software such as DB PowerAmp provides special pre-processing filters for equalising audio levels and improving the sound of audio files.

Analogue audio from sources such as tape recorders and microphones can be introduced via the sockets on the computer's sound card. Most sound cards have two or three miniature 3.5mm stereo jack sockets:

The microphone input often has an automatic gain control, and is suitable mainly for speech. The line input usually has a manual gain control. It requires a higher input signal level, but usually produces better quality.

Most sound cards contain an electronic audio mixer, controlled by the standard MS Windows Volume Control software, or by a similar alternative. This permits the mixing of audio, as well as the control of recording and play-back levels. While in record mode, it displays a thermometer type sound level indicator.

Volume Control can be launched via: Start ... Programs ... Accessories ... Multimedia.


Step 2 - Encode the Audio

Although the standard Real Audio® Player can encode sounds, it is better to use the Real Producer® software. This is available from: http://www.real.com. There is a free, basic version.

Normally, the compression and codec for encoding the audio should be selected to suit replay of the audio via dial-up modem links. This means keeping the output bit rate below about 28kbps.

The resulting Real Audio output file will be called something like:


Step 3 - Create the Launch File and Hyperlink

A special web file is required to launch the web visitor's Real Player® software and initiate the replay. To create this launch file, start MS Windows Notepad, and type just the URL of the encoded sound file on a single line. For example:

http://www.curlewcommunications.co.uk/sound/c-dance.rm

Save this Notepad file as something like: c-dance.ram

Note. This example uses a sub-directory called "sound" for all launch files and sound files on the web site. Although not essential, segregating files makes maintenance easier. Similarly, the launch file and sound file have been given the same name (but different file extensions).

On the web page giving access to the sound file, place a hyperlink pointing to the launch file (ie. not pointing to the actual sound file). For example:

<A href="http://www.curlewcommunications.co.uk/sound/c-dance.ram">Breton Circle Dance</A>


Step 4 - Upload the Files, and Test!!!

Now upload the sound, launch, and web page files to the correct sub-directories on the web server, and test!!!

If there is a problem, check that all URLs are correct.


Examples

There are some Real Audio® streamed audio clips on the Hemyock Castle web site. They can be accessed via:

http://www.hemyockcastle.co.uk/wassail.htm.

For compatibility with previous versions of the Real Player® software, the files replay at 20kbps - achievable by most dial-up internet connections.

If the tape recording had not been damaged, the quality would have been at least "radio quality".


Further Information

For further information, see the extensive help files at the http://www.real.com.




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