# Nanovg-Demo {#v4d_nanovg}

@prev_tutorial{v4d_video}
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| Original author | Amir Hassan (kallaballa) <amir@viel-zu.org> |
| Compatibility | OpenCV >= 4.7 |

Renders a color wheel on top of an input-video using nanovg (OpenGL), does colorspace conversions using OpenCV (OpenCL) and decodes/encodes on the GPU (VAAPI).

@youtube{qVPQaftIGFE}

@include samples/cpp/nanovg/nanovg-demo.cpp