Knowledge Base

Problem

Video recorded by MediaRecorder displays correctly in a media player but appears distorted, black, or incorrect when loaded in EthoVision XT for background grabbing or arena setup. The video window does not render properly.

Details

On systems with both an integrated GPU (e.g., Intel) and a dedicated NVIDIA GPU, Windows may default to using the integrated GPU for EthoVision XT rendering. This can cause improper video rendering, a black or distorted background grab window, or failure to display the video frame during arena setup. Observed with EthoVision XT on multi-GPU systems; may also affect MediaRecorder.

Solution

1. Open Windows Settings > System > Display > Graphics (or search for 'Graphics settings' in the Start menu).
2. Browse to or search for the EthoVision XT executable (typically in C:\Program Files\Noldus\EthoVision XT).
3. Select EthoVision XT from the list and click 'Options'.
4. Choose 'High performance' to force EthoVision to use the dedicated NVIDIA GPU.
5. Repeat this step for MediaRecorder if applicable.
6. Restart EthoVision and attempt to load the video and grab the background image again.
7. Alternatively, open the NVIDIA Control Panel > Manage 3D Settings > Program Settings, add EthoVision XT, and set 'Preferred graphics processor' to 'High-performance NVIDIA processor'.
8. If the problem persists, also refer to the GPU Rendering / CPU Video Processing article if switching to CPU rendering resolves the issue.