Configuring an Audio stream

In the device configuration settings, click "TELEOPERATION" in the top tab. You will find a section for adding a real-time audio stream below:


Clicking on the little + symbol next to AUDIO will give you two options to create an audio stream: with a ROS 1 topic or directly from a Hardware source.


1. ROS topic

Configuring a ROS topic is the easiest method, as it "just works" out of the box. When clicking "Add ROS topic," you'll be asked for a topic name that corresponds to the message type audio_common_msgs/AudioData. Input your topic name and you're set.

2. Add from USB Hardware

This method has a few more steps, but is better for bandwidth and efficiency as it pulls the data directly from the hardware channel. To get started, select "Add from Hardware."

To discover your USB hardware address, in a terminal type arecord -l to list your sound cards. You will see a list much like the following:

$ arecord -l
card 1: tegrasndt210ref [tegra-snd-t210ref-mobile-rt565x], device 9: ADMAIF10 CIF ADMAIF10-9 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: BRIO [Logitech BRIO], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 3: C920 [HD Pro Webcam C920], device 0: USB Audio [USB Audio]
  Subdevices: 0/1
  Subdevice #0: subdevice #0

From here, we select the card number and device number to input into Formant. For example, we might want our HD Pro Webcam C920 audio device, corresponding to card 3 device 0. So in the Formant settings, we add
hw:3,0. Formant will usually be able to auto-detect this for you if you double-click the text field.

When the audio is properly set up, you will get a volume control button in the bottom right of your teleoperation session: