Audio Capture

Audio capture is a sensor codelet for capturing audio packets from microphones. The captured audio is published as 32-bit float data.

Configuration Parameters

Parameter

Description

Default

capture_card_name

The name of the audio device used for capturing audio. Leave this empty if using the system’s default capture device.

sample_rate

The sampling rate in Hz for capturing audio.

16000

num_channels

The number of audio channels to capture.

6

audio_frame_in_milliseconds

The duration of each audio packet in milliseconds.

100

ticks_per_frame

Number of times to query ALSA within the duration of 1 audio frame.

5

Messages

Message

Proto Type

Name

Output

AudioDataProto

audio_capture

Sample Application

The Audio Capture sample application captures audio from a microphone and saves it to a PCM file as raw audio data. This application requires a microphone connected to the host/device and set as the default audio input device in system settings. The specifications of the connected microphone should be used to configure the audio capture component (num_channels and sample_rate). The application is configured to capture 6 channel audio data at a 16kHz sample rate. This data is captured as 100ms audio packets and saved to /tmp/audio-out-f32-16k.pcm.

Platforms: Desktop, Jetson TX/2, Jetson Xavier, Jetson Nano

Hardware: Any microphone