Techniques for Encoding RealAudio

Now that you know about RealAudio's place in SMIL let's talk about the best techniques for encoding it. Most development shops use one of Real's products for encoding. The low end of these, RealProducer, is free from Real. This program contains everything a low volume environment needs to produce RealAudio.

RealProducer

• It allows you to do live broadcasts, provided you have access to a Real Server. You'll need a fairly high-end machine to do the local encoding in near real time.
• Creates scaleable SureStream files for various modem speeds. The program encodes at various bit rates for different modems and then adjusts to the user's modem speed and bandwidth.
• Creates backwards compatible files for RealPlayer 5.0 users
• Control of data rates and Codec selections
• Creates audio and video content that can be streamed serverless from a personal page
• Creates pages with embedded content instead of using the G2 Player window

At Discovery we run a number of live audio broadcasts. Our most successful one is the Science Live show done every Wednesday at 8PM. The show takes place at the Discovery Store in the MCI Center in Washington DC. The audio is encoded in real time. Our sound engineers have a portable studio they have assembled with a laptop, mixing board, several microphones and an ISDN connection. The laptop is a high end one and can handle the real time compression necessary to broadcast live. Trying to accomplish this over a dial-up modem, even a 56K, is going to be very difficult since the bandwidth on the public Internet can be so variable from one minute to the next. Live broadcasting really needs a high speed connection.

With all these features in the low end RealProducer you might wonder why you would need to upgrade to RealProducer Plus or RealProducer Pro. These two packages do have some other features that make them worthwhile. They include:

• Batch conversion - The most important feature for large volume production environments

In RealProducer Pro there are more features added which help in SMIL production and creating template driven sites.

• Drag and Drop batch processing
• SMIL Template integration
• Timeline interface for creating time-based presentations

At Discovery we use RealProducer Plus for its batch conversion. I've found the SMIL templates in RealProducer Pro fairly limited and would either code by hand or use a tool such as Tag Composer 2.0.

I'll walk you through encoding with RealProducer which can be downloaded for free.

RealAudio
The Process of Encoding RealAudio