[JAVA][Beginning Java 8 Games Development]

Chapter 5 ■ An Introduction to Game Design: Concepts, Multimedia, and Using Scene Builder
Because a WAVE or AIFF file will not have any quality loss (as there is also no decompression needed), the PCM
data can be placed straight from the JAR file into system memory! This makes PCM audio great for game sound effects
that are short in duration (0.1 to 1 second), and it can be highly optimized, using 8-bit and 12-bit sample resolution
and 8kHz, 22kHz, or 32kHz sample frequency. Ultimately, the only real way to find out which audio format supported
by JavaFX has the best digital audio compression result for any given digital audio data is to encode your digital audio
in the primary codecs that you know are supported and efficient. I will be outlining this work process later on, when
you add audio to the game, and you will observe the relative data footprint results between the different formats, using
the same source audio sample (see Chapter 15). Then, you will listen to the audio playback quality so that you can
make your final decision concerning the optimal balance between quality and file size . This is the work process that
you will need to go through to develop JavaFX digital audio assets for use in your Java 8 game.
JavaFX also supports the popular MPEG-4 AAC codec. These digital audio data can be contained in MPEG4
containers (.mp4, .m4a, .m4v), or file extensions, and can be played back using any OS. It is important to note that
JavaFX does not contain an MPEG-4 decoder, but instead supports what is called a multimedia container, meaning
that JavaFX uses the OS’s MPEG-4 decoder.
For this reason, and because online listening studies have concluded that the MP3 format has better quality (for
music) than the MP4, you will be using the MP3 format for longer-form audio (game background musical loops) via
the Media and MediaPlayer classes. You will use the PCM WAVE audio format for short-form (1 second or less) audio
(game sound effects, such as shots, bells, yelps, grunts, laughter, cheering, and other such digital audio assets), which
you will use via the AudioClip digital audio sequencing engine (class) that JavaFX so generously provides.
Digital Audio Optimization: Start with CD-Quality Audio, and Work Backward
Optimizing your digital audio assets for playback across the widest range of hardware devices on the market is going
to be easier than optimizing your digital video or digital imagery (and thus animation) across these devices. This
is because there is a much wider disparity between target screen resolutions and display aspect ratios than there is
between types of digital audio playback hardware support across hardware devices (with the possible exception of
new hardware featuring 24-bit HD audio playback hardware compatibility). All hardware plays digital audio assets
well, so audio optimization is a “one audio asset hits all devices” scenario, whereas with the visual (video, image,
animation) part of the equation, you have display screens as large as 4,096 × 2,160 pixels (4K iTV Sets) and as small as
320 × 320 pixels (flip phones and smart watches).
It is important to remember that the user’s ears cannot perceive the same quality difference with digital audio
that the user’s eyes can with digital imagery, 2D animation, and digital video. Generally, there are three primary “sweet
spots” of digital audio support across all hardware devices that you should target for support for Java game audio.
Lower-quality audio, such as short narration tracks, character exclamations, and short-duration sound effects,
can achieve remarkably high quality by using a sampling rate of 8kHZ or 22kHz, along with 8-bit or 12-bit sampling
resolution. Medium-quality audio, such as long narration tracks, longer-duration sound effects, and looped
background (ambient) audio, can achieve a very high quality level by using a 22kHz or 32kHz sampling rate, along
with a 12-bit or 16-bit sampling resolution.
The high-quality audio assets, such as music, should be optimized approaching CD-quality audio and will use
a 32kHz or 44.1kHz sampling rate, along with the 16-bit data sampling resolution. For HD-quality audio, being at
the ultra-high end of this audio spectrum, you would use the 48kHz sampling rate, along with the 24-bit digital audio
data sampling resolution. There is also an unnamed, “somewhere in the middle” high-end audio specification, using
a 48kHz sampling rate, along with a 16-bit data sampling resolution, which just happens to be what Dolby THX used
to use for its high-end audio experience technology in movie theaters (back in the day).
Ultimately, it comes down to the quality–file size balance results that emerge from the digital audio data footprint
optimization work process, which can be amazing. Therefore, your initial work process for optimizing your digital
audio assets across all these hardware devices is going to be to create baseline 16-bit assets, at either 44.1kHz or
48kHz, and then optimize (compress) them, using the different formats supported in JavaFX. Once that work process
is completed, you can see which resulting digital audio assets provide the smallest data footprint, along with the
highest quality digital audio playback. After that, you can reduce your 44.1KHz or 48kHz data to 32kHz and save
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