Game Development Reference
In-Depth Information
Lower sampling rates, such as 8kHz, 11kHz, and 22kHz, are the ones that you are
going to use in your games, as, with careful optimization, these can yield high-quality
sound effects and arcade music. These rates would be optimal for sampling any voice-
based digital audio as well, such as movie dialogue or an e-book narration track. High-
er audio sample rates, such as 44.1kHz, would be more appropriate for music, and
sound effects that need a high dynamic range (high fidelity), such as rumbling thunder,
could use 48kHz. Higher sample rates will allow audio reproduction that exhibits
movie theater (THX) sound quality, but this is not required for most games.
Digital Audio Streaming: Captive Audio vs. Streaming
Audio
As with digital video data, digital audio data can be either captive within the applica-
tion distribution file (in the case of Java, a .
JAR
file) or
streamed
, using remote data
servers. Similar to digital video, the upside to streaming digital audio data is that it can
reduce the data footprint of the application file. The downside is reliability. Many of
the same concepts apply equally well to audio and video. Streaming audio will save the
data footprint, because you do not have to include all that heavy new media digital au-
dio data in your .JAR files. So, if you are planning on coding a Jukebox application,
you may want to consider streaming your digital audio data; otherwise, try to optimize
your digital audio data so that you can include them (captive) inside the .JAR file. This
way, the data will always be available to the application's users when they need it!
The downside to streaming digital audio is that if a user's connection (or the audio
data server) goes down, your digital audio file may not always be present for your end
users to play and listen to, using your game application! The reliability and availability
of digital audio data are a key factor to be considered on the other side of this
streaming-versus-captive trade-off. The same would apply to digital video assets as
well.
Again, as with digital video, one of the primary concepts in regard to streaming
your digital audio is the bit rate of the digital audio data. As you learned in the previous
section, the bit rate is defined during the compression process. Digital audio files that
need to support lower bit-rate bandwidth are going to have more compression applied
to the audio data, which will result in lower quality. These will stream (play back) more
smoothly across a greater number of devices, because fewer bits can be quickly trans-
ferred as well as processed more easily.
