The
Encoding
class names the specific type of data representation used for an audio stream. The encoding includes aspects of the sound format other than the number of channels, sample rate, sample size, frame rate, frame size, and byte order.
One ubiquitous type of audio encoding is pulse-code modulation (PCM), which is simply a linear (proportional) representation of the sound waveform. With PCM, the number stored in each sample is proportional to the instantaneous amplitude of the sound pressure at that point in time. The numbers may be signed or unsigned integers or floats. Besides PCM, other encodings include mu-law and a-law, which are nonlinear mappings of the sound amplitude that are often used for recording speech.
You can use a predefined encoding by referring to one of the static objects created by this class, such as PCM_SIGNED
or PCM_UNSIGNED
. Service providers can create new encodings, such as compressed audio formats, and make these available through the AudioSystem
class.
The Encoding
class is static, so that all AudioFormat
objects that have the same encoding will refer to the same object (rather than different instances of the same class). This allows matches to be made by checking that two format's encodings are equal.