Realtime Audio

Sound Files | Realtime Audio

Realtime Audio

The ability to receive audio signals in "real time" (as it is happening) is a rapidly growing development on the Web. We shall demonstrate some applications with RealPlayer 5.0, a freeware realtime audio player available for PowerMacs, Windows, and Unix systems from RealNetworks (a commercial version with additional features is available from the same site; you can also download the free RealPlayer 4.0 there, which plays both audio and video but is presently available for fewer systems). RealPlayer can function either as an independent application to access realtime audio on the net, or as a plugin application that is launched automatically by the Web browser when you connect to a site transmitting a realtime audio stream. The newest browsers also now offer integrated streaming audio that is similar in function to RealPlayer.
Some Caveats

The transmission of high quality realtime audio on the network generally requires at least 28.8 kbaud modem connectivity. You can still connect at slower speeds, but the sound quality will be diminished. Over ISDN and faster connections the sound quality can be quite high from sites offering a 28.8 kbaud stereo audio stream if you have stereo speakers on your computer.
The Timecast RealAudio Guide

A starting point for exploring realtime audio sites on the Internet is the real guide From this site, you can find a variety of News, Industry, Business, and on-line radio broadcasts of all types, as well as special events (sample special event: the live audio feed from Space Shuttle missions can often be found at SPACEZONE). Assuming that RealPlayer has been installed and configured to launch automatically from your browser, you can explore a variety of sites simply by clicking and following the instructions.
Example: News and Information Soundclips

As an example, let us use the real guide page to select an audio clip of a story from National Public Radio (NPR), and an audio clip from the informative Earth and Sky daily radio thumbnail sketch. From the real guide, select the "News" tab. On the resulting page, use the search field to type in "NPR" followed by a keyboard return. On the resulting page click a story of interest. Once you have made the selection, click the "Start" button on the RealAudio Player to play the clip. Repeat the preceding sequence but use the search string "earth and sky". Follow the instructions on the resulting page to play an audio clip.
Example: Live Rock Radio from Sweden
The preceding example played a fixed soundclip. A more powerful application is the transmission of "live" sound. As an example, let us illustrate the use of "on demand" radio by connecting to the live audio stream for a Swedish rock radio station, FM 105.5 "Bandit Radio" (we can't do education ALL the time!).
Use the browser to access the real guide. Select the "all stations" link. on the resulting page, select "STATIONS", and on the resulting page type into the search field "bandit 105.5" followed by a return. On the resulting page click on the link "Bandit 105.5 Rock". This will bring up a page written in Swedish. Wait a few seconds, or click the link near the top to forward you to a new address. Click the top right "Play" button. This should bring up a window similar to the following

which will load data for a few seconds and then launch the audio feed for the station broadcast (the DJ is Swedish but, as is true the world over, most songs on rock radio are in English). This audio stream will generally remain on as long as the above RealPlayer window remains open, even if you go and do other things with the browser.


			Sound Files \| Realtime Audio
		Realtime Audio The ability to receive audio signals in "real time" (as it is happening) is a rapidly growing development on the Web. We shall demonstrate some applications with `RealPlayer` `5.0`, a freeware realtime audio player available for PowerMacs, Windows, and Unix systems from RealNetworks (a commercial version with additional features is available from the same site; you can also download the free `RealPlayer` `4.0` there, which plays both audio and video but is presently available for fewer systems). `RealPlayer` can function either as an independent application to access realtime audio on the net, or as a plugin application that is launched automatically by the Web browser when you connect to a site transmitting a realtime audio stream. The newest browsers also now offer integrated streaming audio that is similar in function to RealPlayer. Some Caveats The transmission of high quality realtime audio on the network generally requires at least 28.8 kbaud modem connectivity. You can still connect at slower speeds, but the sound quality will be diminished. Over ISDN and faster connections the sound quality can be quite high from sites offering a 28.8 kbaud stereo audio stream if you have stereo speakers on your computer. The Timecast RealAudio Guide A starting point for exploring realtime audio sites on the Internet is the real guide From this site, you can find a variety of News, Industry, Business, and on-line radio broadcasts of all types, as well as special events (sample special event: the live audio feed from Space Shuttle missions can often be found at SPACEZONE). Assuming that `RealPlayer` has been installed and configured to launch automatically from your browser, you can explore a variety of sites simply by clicking and following the instructions. Example: News and Information Soundclips As an example, let us use the real guide page to select an audio clip of a story from National Public Radio (NPR), and an audio clip from the informative Earth and Sky daily radio thumbnail sketch. From the real guide, select the "News" tab. On the resulting page, use the search field to type in "NPR" followed by a keyboard return. On the resulting page click a story of interest. Once you have made the selection, click the "Start" button on the RealAudio Player to play the clip. Repeat the preceding sequence but use the search string "earth and sky". Follow the instructions on the resulting page to play an audio clip. Example: Live Rock Radio from Sweden The preceding example played a fixed soundclip. A more powerful application is the transmission of "live" sound. As an example, let us illustrate the use of "on demand" radio by connecting to the live audio stream for a Swedish rock radio station, FM 105.5 "Bandit Radio" (we can't do education ALL the time!). Use the browser to access the real guide. Select the "all stations" link. on the resulting page, select "STATIONS", and on the resulting page type into the search field "bandit 105.5" followed by a return. On the resulting page click on the link "Bandit 105.5 Rock". This will bring up a page written in Swedish. Wait a few seconds, or click the link near the top to forward you to a new address. Click the top right "Play" button. This should bring up a window similar to the following which will load data for a few seconds and then launch the audio feed for the station broadcast (the DJ is Swedish but, as is true the world over, most songs on rock radio are in English). This audio stream will generally remain on as long as the above `RealPlayer` window remains open, even if you go and do other things with the browser.