Zynq Ult VCU TRD User Guide
28
UG1250 (v2019.1) May 29, 2019
Chapter 3:
APU Software Platform
Audio
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
.
For this TRD, the supported parameters are:
• Sampling rate: 48 kHz
• Sample width: 24 bits per sample
• Sample encoding: Little endian
• Number of channels: 2
• Supported format: S24_32LE
X-Ref Target - Figure 3-5
Figure 3-5:
Audio Design
ALSA Library API (libasound)
vcu_qt
vcu_gst_app
User Space
OS
(Kernel)
HW
HDMI Rx Subsystem
HDMI Tx Subsystem
Audio Formatter IP
Audio Hardware
HDMI Rx Driver
HDMI Tx Driver
Audio Formatter Driver
ALSA Driver
SDI Rx Subsystem
SDI Tx Subsystem
X22068-050519
