How To | Routing audio using USB audio bridging when NV-21-HU USB-C DisplayPort (DP Alt Mode) is used

This article will provide an instruction on a workaround to route audio using USB audio bridging when USB-C DisplayPort is used.

Updated at November 21st, 2023

Procedure


Note

In 9.8.1, embedded audio over USB-C DisplayPort (DP Alt Mode) is not supported.

This article will provide an instruction on a workaround to route audio using USB audio bridging as an alternative to embedded audio over USB-C DisplayPort until 10.0 is released to support embedded audio over USB-C DisplayPort. Read this awareness article before proceeding.

 
  1.  Enable USB Audio Bridge on the NV-21-HU Encoder.
  2.  Route all video sources as needed.
  3. Place USB Sound Card In component in the design (It is going to be used as an Audio source for alt-mode DisplayPort mode)
  4. On the output display connected to the NV-21-HU Decoder, set Audio Source to Audio Input Pins and Audio Channels to 2. This enables an external audio source.

  5.  Place a 2x1 stereo matrix mixer in the design. Mix Sound Card stereo audio source and HDMI stereo audio source to the mixer. Route the output to the output display connected to the NV-21-HU Decoder. The resulting design should look like this:

Note

  • This workaround does not enable embedded audio over USB-C DisplayPort, it takes advantage of USB audio bridging over USB-C.
  • One single USB-C cable is used for both USB-C DisplayPort video and USB Audio Bridging. 
  • Audio should be manually mixed since the audio does not follow the video.
  • There is no breakaway audio from the USB-C source component.
  • Embedded audio over HDMI functions as expected.
 

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