Advanced Linux Sound Architecture (ALSA) arranges hardware audio devices and their components into a hierarchy of cards, devices, and subdevices. It reflects the capabilities of our hardware as seen by ALSA.
ALSA cards correspond one-to-one to hardware sound cards. A card can be denoted by its ID or by a numerical index starting at zero.
ALSA hardware access happens at the device level. The devices of each card are enumerated starting from zero.
In this TRD design, sound cards are created for the HDMI-RX capture pipeline, the HDMI-TX playback pipeline, and the I2S RX and SDI RX Capture and I2S TX and SDI TX playback pipelines. See This Figure.
For this TRD, the supported parameters are:
•Sampling rate: 48 kHz
•Sample width: 16, 24, or 32 bits per sample
•Sample encoding: Little endian
•Number of channels: 2, 8
•Supported format: S24_32LE (2-channel audio)