Codec refers to a device or program that encodes an audio signal into digital format and decodes digital signals back into analog format, or acts as a digital signal converter. It includes an analog-to-digital converter (ADC) or a digital-to-analog converter (DAC). The major audio interfaces are I2S, HDA, SPDIF, and analog. Cmedia Codec is responsible for the encoding and decoding of audio data, and facilitates the transfer of audio data between these major audio interfaces.