Real Media Files
You someday might want to experiment with using the microphone attached to your computer to record your lectures or other messages you want to make available to your students. There are two basic ways to deliver those kinds of recordings via Manhattan.
The first is use software that creates sound files in a non-streaming format such as WAV and simply attach that file to a Manhattan message. "Non-streaming" means that the file must be fully transferred to the student's computer before any sound is heard. One way for you to experiment with WAV files is to work with the "Sound Recorder" utility that comes with Windows - look for it under "Accessories" in your Start menu. Besides the fact that Sound Recorder only allows you to make recordings up to 60 seconds long, it is the other disadvantages of WAV audio files that make them impractical for your online classroom. A 60-second voice recording made with Windows Sound Recorder generates a 1.25 Megabyte WAV file. A file that size would take about 4 minutes for your students to download using a 56 Kbps modem under ideal conditions.
The second, and preferred, method for making voice recordings available to your students is to use a streaming file format. A "streamed" sound recording can be heard as it arrives at your computer, instead of having to first download the entire file. Your students can begin to listen to a 30 minute recorded lecture a few moments after they click on the file name, instead of having to wait for the entire file to transfer.
Manhattan provides basic support for streaming of the popular Real Audio/Real Video (also called Real Media) file formats. In a nutshell, when Manhattan encounters a file that ends with a *.rm extension, it sends a special instruction to the web browser when the file is downloaded that starts the RealMedia Player.
Installing RealPlayer
Working with Real Audio is similar to working with PDF files (see the previous section) in that you and your students will need special software to listen to the files, while another, separate software package is required to create the recordings. The player software is called Real Player and a free version is available from http://www.realnetworks.com. RealPlayer is widely used on the Internet, and you might already have a version of the software installed on your computer. Nevertheless, the software is updated frequently, and it often is worthwhile to upgrade to the latest version.
In the interest of running a profitable company, the RealNetworks web site gives you plenty of opportunities to purchase the enhanced version of their player before you are delivered to the page where you can download the free version. Make a game out of it. Visit http://www.realnetworks.com and start your adventure by looking for a "Real Player" button. See how long it takes you to find the FREE RealPlayer Basic version. Read the fine print. Look at the bottom of the pages. It's there. Really!
As always, whenever you download software, pay attention to both the name of the file (which will be very descriptive) and the name of the folder where you chose to save the file. Once the file has been downloaded, close all running programs, then run the program you have just downloaded. Follow the instructions on the installation program screens. RealPlayer will automatically add itself to your web browsers' lists of 'plugins', so you will be able to immediately listen to Real Audio files the next time you are on the web.
Posting Real Media files to Manhattan
As of this writing, the preferred tool for creating Real Media files is Helix Producer. The basic version is available for free download from http://www.realnetworks.com
Audio files created with Helix Producer can simply be attached to any Manhattan message just as if they were any other type of file. You can attach more than one audio file to a single message, and you can mix audio files with other file types in the same message. When someone clicks on the file attachment their web browser will attempt to launch RealPlayer and they can begin to listen to the file immediately as it is streamed to them.
Behind the scenes, Manhattan treats files the end in *.rm in special way. When you click on a file ending in *.rm, instead of sending the file Manhattan sends a short Real Audio Metafile or 'ram' file to the browser. Upon receiving the ram file, the browser launches RealPlayer which in turn retrieves the actual *.rm file from the Manhattan server, playing the content as the file is retrieved. This method is called HTTP streaming and is how Real Audio and Real Video files can be streamed from any ordinary web server.
This web server streaming method, however, is not as robust as streaming Real Audio and Real Video files from a server equipped with RealNetwork's Helix server software. It works OK for small numbers of users who need to listen to simple audio presentations over a relatively fast Internet connection. If your school intends to get into streaming educational content over the Internet in a big way, you will probably want to experiment with RealNetwork's Helix server software to supplement Manhattan's basic services.