The software processes for playing back and capturing audio data are similar. This
section describes the common steps
Opening your PCM device
The first thing you need to do in order to playback or capture sound is open a connection to a PCM playback or capture
device.
Configuring the PCM device
The next step in playing back or capturing the sound stream is to inform the device of the format of the data that
you're about to send it or want to receive from it.