generateLut.js

function generateLutFilter(hexColorsToExclude) {
  function hexToRgb(hex) {
    const bigint = parseInt(hex, 16);
    const r = (bigint >> 16) & 255;
    const g = (bigint >> 8) & 255;
    const b = bigint & 255;
    return { r, g, b };
  }

  let lutFilter = "lutrgb=";
  let rConditions = [];
  let gConditions = [];
  let bConditions = [];

  for (const hexColor of hexColorsToExclude) {
    const { r, g, b } = hexToRgb(hexColor);
    rConditions.push(`if(eq(val\\,${r})\\,${r}\\,`);
    gConditions.push(`if(eq(val\\,${g})\\,${g}\\,`);
    bConditions.push(`if(eq(val\\,${b})\\,${b}\\,`);
  }

  const rFilter = rConditions.length > 0 ? rConditions.join("") + "255-val" + ")".repeat(rConditions.length) : "255-val";
  const gFilter = gConditions.length > 0 ? gConditions.join("") + "255-val" + ")".repeat(gConditions.length) : "255-val";
  const bFilter = bConditions.length > 0 ? bConditions.join("") + "255-val" + ")".repeat(bConditions.length) : "255-val";

  lutFilter += `r='${rFilter}':g='${gFilter}':b='${bFilter}'`;

  return lutFilter;
}

const hexColorsToExclude = ["008000", "007ACC"];
const lutFilter = generateLutFilter(hexColorsToExclude);

const ffmpegCommand = `ffmpeg -i input.mp4 -vf "${lutFilter}" -c:a copy output.mp4`;

console.log(ffmpegCommand);