Question about input sources loading

[Salmondx]

I was trying to debug why my example stuck on processing and found this code in library sources:

/**
 * Retrieve the URL and type of a media source
 * @param {string|RawSource} source
 */
const getMetadata = async (page, id, source) => {
  let data
  let type
  if (typeof source === 'string') {
    // Source is a path. Read into a new buffer.
    data = fs.readFileSync(source, 'base64')
    const extension = source.substring(source.indexOf('.') + 1)
    type = mime.getType(extension)
  } else {
    // Source is an object of the form {type: string, data: Buffer}
    data = source.data.toString('base64')
    type = source.type
  }
  // Prepend base64 header
  url = `data:${type};base64,${data}`
  return { url, type }
}

As I can see files are just loaded as base64 strings to memory, correct? So it is not possible to use etro-node with large files or multiple input sources?

Thanks in advance!