Text Height
txt-h
Sets the maximum height of a text overlay bounding box on video in pixels.
txt-h constrains the text rendering area vertically. Use in combination with txt-fit to control how text is sized or clipped within the bounding box. Use txt-h[N] for a specific text layer.
This parameter works identically to txt-h in the Rendering API.
For the full list of text overlay parameters, see the Text Overlays overview.