FFMPEG utf-8特殊字符在视频水印文本中无效

$input = "input.flv";
$output = "output.mp4";
$font = "arial.ttf";
$text = "ମୋ ପ୍ରତିଭା";

$command = "ffmpeg -i $input -vf \"format=yuv444p, drawbox=y=ih/PHI:color=black@0.4:width=iw:height=48:t=max, drawtext=fontfile=$font:text='$text':fontcolor=white:fontsize=24:x=w-tw:y=(h/PHI)+th, format=yuv420p\" -c:v libx264 -c:a copy -movflags +faststart $output";

结果：

这里我想放utf-8字符。但我可以在我的视频输出中获取正确的文本。请帮助我。

Here I want to put utf-8 character. But I am anable to get proper text in my video output. Please help me.