Code, Code, Code Your Sound / And You'll Make It Stream...

Stream It, Dano

Doing this complicated two-step lets you do something very important: you can now stream RealMedia files using a standard HTTP server. If your RealAudio files are encoded to a single rate, and that rate is less than or equal to the data rate that a viewer's Internet connection can handle, the audio or video will actually stream automatically, without the necessity for you to buy, license, download, or configure a RealAudio/RealMedia server.

This streaming is limited in flexibility, but for most sites that aren't solely music- or video-oriented, this is a fantastic feature. It means you can simply "drop in" RealAudio files easily, without having to worry about a separate server, and without your visitors having to wait until the entire file downloads before they can hear or see your content. Be warned, however, that not using a direct RealMedia server means that a clever visitor will be able to bootleg your file by grabbing the content file out of their browser cache, or in numerous other ways. Basically, your content is not secure at all if you're not using a RealMedia server, so don't post high-quality full-length RealAudio samples of your newest hit song if you don't want them spread all over the world by tomorrow morning.

Now, if your RealAudio files happen to be encoded to a higher rate than the connection can handle (such as 44.1 KHz stereo audio attempting to go over a 28.8 Kbps connection), and if your viewer has a newer RealPlayer with the PerfectPlay option checked, the file will be downloaded to their machine, then played automatically (assuming you've also enabled PerfectPlay when encoding it). Or they can right-click on the link, and "save as" to grab it.

Decoding Codecs

RealNetworks has a technical document that contains an interesting section called Choosing RealAudio Codecs. It shows charts detailing exactly what frequency response you will get from picking one of the almost three dozen different codecs that they use. To put it mildly, it's quite a complex decision, which is why RealNetworks — and you — would love for everyone to download their new G2 player. G2 can update itself automatically and play any RealMedia content ever created, and using RealProducer, you can have it automatically adjust itself to the user's available bandwidth using their SureStream technology.

Unfortunately not everyone lives on the cutting edge of technology, so if you want people with older players to hear your content instead of clicking off to another site in disgust, you have to give them something they can deal with (assuming they have a RealAudio player at all, which most people actually do).

The WebDeveloper.com Secret Guide to RealAudio
The WebDeveloper.com Secret Guide to RealAudio
Choosing the Right Codec