# Nanovg-Demo {#v4d_nanovg}

@prev_tutorial{v4d_video}
@next_tutorial{v4d_shader}

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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).

\htmlinclude "../samples/example_v4d_nanovg-demo.html"

@include samples/nanovg-demo.cpp