javascript - YouTube iFrame API captions displaySettings does not change fontStyle -

for valid youtube video captions, following options returned.

  player.getoption("captions", "displaysettings");   {     background:"#080808",     backgroundopacity:0.75,     charedgestyle:"none",     color:"#fff",     fontfamily:4,     fontfamilyoption:"propsans",     fontsizeincrement:0,     textopacity:1,     windowcolor:"#080808",     windowopacity:0   } 

attempting change of above properties shown below doesn’t result in changes caption style.

  ytplayer.setoption("captions", "displaysettings", {fontfamily: 2}); 

is api broken or there missing step?

if check options setoption in iframeapi, can see there's no fontstyle option, fontsize

if you're using this blog reference, note post written in 2015 , it's html5 player. writer warned:

"i'm not sure whether means api reference out of date or undocumented options unofficial , might disappear without notice. since latter might possibility, should exercise caution in using these options."

so, follow official documentation.