listAudioDevices

Get a list of available audio devices on the NVIDIA hardware

Since R2021a

Add-On Required: This feature requires the MATLAB Coder Support Package for NVIDIA Jetson and NVIDIA DRIVE Platforms add-on.

Syntax

audiolist = listAudioDevices(hwObj,audioType)

Description

audiolist = listAudioDevices(hwObj,audioType) returns a list of Advanced Linux Sound Architecture (ALSA) audio devices connected to your NVIDIA^® hardware. The type of listed audio devices (capture or playback) depends on the audioType specified in the function.

Examples

List Available ALSA Audio Input Devices

To list ALSA audio input devices connected to the hardware:

Create a connection to the NVIDIA hardware.

hwobj = jetson('jetson-board-name','ubuntu','ubuntu');

Use the listAudioDevices function. In the function, specify audioType as 'capture'. The function returns a structured array with field names that correspond to the properties of ALSA audio input devices connected to the jetson object.

devices = listAudioDevices(hwobj,'capture')

devices = 

  1×2 struct array with fields:

    Name
    Device
    Channels
    BitDepth
    SamplingRate

In this example, the function returns a 1-by-2 array, indicating that two audio input devices are connected to the jetson object.

View the properties of the first ALSA audio input device. For example,

devices(1)

ans = 

  struct with fields:
         Name: 'USB-Audio-PlantronicsBlackwire325.1↵
                PlantronicsPlantronicsBlackwire325.1atusb
                -3530000.xhci-2.3,fullspeed'
       Device: '2,0'
     Channels: {'2'}
     BitDepth: {'16-bit integer'}
 SamplingRate: {'8000'  '48000'} 

List Available ALSA Audio Output Devices

To list all connected ALSA audio output devices:

Create a connection to the NVIDIA hardware.

hwobj = jetson('jetson-board-name','ubuntu','ubuntu');

Use the listAudioDevices function. In the function, specify audioType as 'playback'. The function returns a structured array with field names that correspond to the properties of ALSA audio output devices connected to the jetson object.

devices = listAudioDevices(hwobj, 'playback')

devices = 

  struct with fields:
            Name: 'USB-Audio-PlantronicsBlackwire325.1↵
                   PlantronicsPlantronicsBlackwire325.1atusb
                   -3530000.xhci-2.3,fullspeed'
          Device: '2,0'
        Channels: {'2'}
        BitDepth: {'16-bit integer'}
    SamplingRate: {'8000'  '48000'}

In this example, the function returns a 1-by-1 array, indicating that one audio output devices is connected to the jetson object.

Input Arguments

hwObj — Connection to a specific NVIDIA hardware board

jetson object | drive object

Connection to a specific NVIDIA hardware board, specified as a jetson or drive object.

audioType — Type of audio device

'capture' | 'playback'

Specify the type of audio to be listed:

• 'capture' — ALSA audio input devices connected to the NVIDIA hardware.

• 'playback' — ALSA audio output devices connected to the NVIDIA hardware.

Example: audiolist = listAudioDevices(hwObj,'playback')

Output Arguments

audiolist — List of connected ALSA audio devices

table

The type of listed audio devices depends on the audioType specified in the function. The resulting structured array contains these details:

• Name: The name of the audio device.

• Device: The device identifier for the audio device: the card number and the device number, separated by a comma.

• Channels: The number of channels supported by the audio device. For example, in List Available ALSA Audio Output Devices, the audio device supports audio from two channels only.

• BitDepth: The data type in which the audio device reads or sends data.

• SamplingRate: The sample rates supported by the audio device.

Version History

Introduced in R2021a