OBS Studio Clean HDMI Output to Hardware Encoder

This article provides a step-by-step guide on how to route a clean, high-quality video and audio feed from OBS Studio directly to an external hardware encoder using your computer’s HDMI output. By utilizing the OBS “Fullscreen Projector” feature and configuring your OS display settings, you can output a dedicated feed free of software UI elements, overlays, or system cursors directly to your streaming or recording hardware.

Step 1: Connect the Hardware and Configure Windows

Before configuring OBS, you must physically connect your computer to the hardware encoder and ensure your operating system recognizes it as a secondary display.

  1. Connect an HDMI cable from your computer’s graphics card (GPU) HDMI output port to the HDMI input port on your external hardware encoder.
  2. On your PC, right-click the desktop and select Display settings.
  3. Under the Multiple Displays dropdown, select Extend these displays. Do not use “Duplicate” or “Clone” mode, as this will mirror your main monitor and display the OBS interface itself.
  4. Select the virtual display that represents your hardware encoder and set its resolution (typically 1920x1080) and refresh rate (typically 60Hz) to match your encoder’s optimal input specifications.

Step 2: Output the Clean Video Feed from OBS

Once the hardware encoder is recognized as an extended display, you can project a clean feed of your OBS Program mix to it.

  1. Open OBS Studio.
  2. Locate the Program preview window (the right-side window if you are in Studio Mode, or the main preview window if you are not).
  3. Right-click anywhere inside the preview window.
  4. Hover your mouse over Fullscreen Projector (Program).
  5. A list of available monitors will appear. Select the monitor that corresponds to your external hardware encoder (e.g., “Display 2”).

OBS will immediately send a full-screen, clean video feed of your program output to the hardware encoder, bypassing all user interface elements, docks, and menus.

Step 3: Route Audio to the HDMI Output

To ensure your audio accompanies the video feed through the HDMI cable to the encoder, you must configure your OBS audio monitoring settings.

  1. In OBS Studio, click on Settings in the bottom-right corner, then select the Audio tab on the left.
  2. Scroll down to the Advanced section.
  3. Locate the Monitoring Device dropdown and select the audio output associated with your HDMI connection (this is often labeled with your GPU name, your encoder name, or “Intel/NVIDIA/AMD High Definition Audio”). Click Apply and then OK.
  4. In the main OBS window, look at the Audio Mixer dock. Click the three dots (or gear icon) next to any audio source you want to send to the encoder and select Advanced Audio Properties.
  5. Find the audio tracks you want to send and change their Audio Monitoring status from “Monitor Off” to Monitor and Output (or “Monitor Only”).

Your selected audio sources will now be mixed and embedded directly into the HDMI video signal being sent to your external hardware encoder.