cornerRadius property
The proportion of the radius to the width of the canvas. The default value is 0.0.
Only server-side stream mixing can set this parameter.
After you set the value, width_px, height_px, and radius_px are calculated based on width, height, radius, and the width of the canvas. If radius_px < min(width_px/2, height_px/2) is met, the value of radius is set valid; if not, radius_px is set to min(width_px/2, height_px/2), and radius is set to the proportion of radius_px to the width of the canvas.
Implementation
double cornerRadius;