ffmpeg -y -i "in.mkv" -vf eq=gamma=1.25,format=yuv444p10,colorspace=all=bt709:format=yuv444p10 "out.mkv"

/**
 * Formats a metavar help string.
 * 
 * This returns a string that explains how many arguments an option takes.
 * For example, an option that takes two arguments and has a metavar
 * 'FOO' will get 'FOO FOO' as help string.
 * 
 * The 'shortZeroOrMore' changes the behavior of the * nargs value and
 * determines its size/verbosity.
 * 
 * Options with a variable number of arguments get a string that indicates
 * how many the user may pass. See the formatArg() description for examples.
 */
function formatMetavar(arg, shortZeroOrMore = false) {
  const {L} = this
  const {nargs} = arg.opts

  // Helper function for wrapping metavar strings.
  const getMetavar = (n, ellipsis) => ellipsis
    ? L.argOptionalEllipsis('')
    : (arg.metavars[n] ? arg.metavars[n].content : arg.metavars[arg.metavars.length - 1].content)
  // Helper function for adding brackets.
  const addBrackets = (str, needed) => needed
    ? L.argOptionalBrackets(str)
    : str
  // Joins items together using the appropriate joiner for the language.
  const collect = items => L.joinMetavars(omitFalsy(items))
  
  let itemTypes = []

  if (isString(nargs)) {
    // FOO [FOO ...]
    if (nargs === '+') itemTypes.push({optional: false}, {optional: true}, {optional: false, ellipsis: true})
    // [FOO ...]
    if (nargs === '*' && shortZeroOrMore) itemTypes.push({optional: true}, {optional: false, ellipsis: true})
    // [FOO [FOO ...]]
    if (nargs === '*' && !shortZeroOrMore) itemTypes.push({optional: true}, {optional: true}, {optional: false, ellipsis: true})
    // [FOO]
    if (nargs === '?') itemTypes.push({optional: true})
  }

  if (isInteger(nargs) || (nargs == null && arg.typeData.properties.takesValues)) {
    const amount = nargs || 1
    for (let n = 0; n < amount; ++n) {
      itemTypes.push({optional: false})
    }
  }

  // Work from the inside out to properly wrap the brackets.
  itemTypes = itemTypes.reverse()
  let result = ''
  for (let n = 0; n < itemTypes.length; ++n) {
    const type = itemTypes[n]
    const metavar = getMetavar(itemTypes.length - n - 1, type.ellipsis)
    result = addBrackets(collect([metavar, result]), type.optional)
  }

  return result
}