Audio

This chapter is an exploration of sound on computers in general and specifically how the architecture of the Raspberry Pi supports music and all sorts of other sound manipulations. It discusses analog versus digital audio, sound over High Definition Multimedia Interface (HDMI), 1-bit digital analog conversion (DAC), both signal and sound processing, and Inter-IC Sound (I2S, a communications protocol for carrying digital audio signals). The chapter also covers the Raspberry Pi's onboard sound, both the input and output features. Compression of an audio waveform allows better quality audio on transmission media than other degrade reproduction. Recordings of old time AM broadcast and movies from the 1930s and 1940s provide a prime example. Features that enable to modify all or parts of sound files are called effects. The audio editing techniques in the chapter work in most Linux distros on the Raspberry Pi, but authors have used Raspbian for the examples.