Function crc32

packages/engine/src/utils/ffprobe.ts:128–138

(buf: Buffer)

}

function crc32(buf: Buffer): number {
  let crc = 0xffffffff;
  for (let i = 0; i < buf.length; i++) {
    crc ^= buf[i] ?? 0;
    for (let bit = 0; bit < 8; bit++) {
      const mask = -(crc & 1);
      crc = (crc >>> 1) ^ (0xedb88320 & mask);
    }
  }
  return (crc ^ 0xffffffff) >>> 0;
}

export function extractPngMetadataFromBuffer(buf: Buffer): StillImageMetadata | null {
  if (