From doc, I use below command to draw a box and fill it with color.
ffmpeg -i output.mp4 -vf "drawbox=x=0:y=570:w=in_w:h=40:[email protected]:t=fill" output_1.mp4
I got an error.
[Parsed_drawbox_0 @ 0x7fa5c6f05840] [Eval @ 0x7ffee6f23bc0] Undefined constant or missing '(' in 'fill' Last message repeated 5 times [Parsed_drawbox_0 @ 0x7fa5c6f05840] Error when evaluating the expression 'fill'. [Parsed_drawbox_0 @ 0x7fa5c6f05840] Failed to configure input pad on Parsed_drawbox_0
You seem to be using an older ffmpeg version; upgrade or use max in place of fill.