Game Development Reference
In-Depth Information
Now that you know a
little bit about what
kinds of sounds you
might i nd inside a
game, let's put you
in an interactive
environment. Go
to the App in the
Holodeck Section and
select the 'A Day In the
Forest' demo. Enjoy
a nice walk through
a little mushroom
village. A special
place where you will
have the opportunity
to observe changes
in your sonic reality
in real time, and to
experience how game
sounds are triggered.
Credit:
Jeremy Engel.
Formats for Sound Files
Sound i les come in many formats. Some game platforms use proprietary
formats, while others use open standards such as Ogg Vorbis. The list is
long, so for the purposes of this course, we will look at a select few, the
ones you're most likely to see.
Open, Uncompressed Audio File Formats
These i le types are examples of linear pulse-code modulation (PCM)
audio. The workings of PCM audio is a complex topic, but what you
should know is that an uncompressed format generally of ers you the
best quality audio (depending on the sampling rate or bit depth the
sound was originally recorded at). As we mentioned in Level 3, audio
i le size is dependent on sampling rate and bit depth. For example, a
sound recorded with a bit depth of 16 bits at a sampling rate of 44.1KHz
results in a i le of approximately 10MB per minute of stereo sound or
5MB per minute of mono sound (also commonly known as the Red Book
standard).
Interleaving
Besides bit depth and sample rate, there is another characteristic of
audio i les to be aware of, and this pertains to how a sound channel
is treated in the i le. If a i le contains more than a single channel, it is
referred to as an
interleaved
i le
.
The term means essentially to join
channels together. So a single stereo i le that has two channels is called
an interleaved i le, whereas two separate Left and Right i les with the
same material are referred to as non-interleaved (sometimes referred to
