Sending sound, image (or even video) file from local disk to Emscripten. What is the best format? Base64, blob, typed array or something else?

Can anybody tell me which format is the best for sending files from disc to Emscripten?
Right now I can send wav. files encoded as Int8Array. Is it better to convert it to base64 or blob instead? Or is the Int8Array a good choice?
Regarding Images: I wonder if it is better to send base64 or blob (base64 is readable directly from ofImage if I understand it right)? Actually base64 would be packed into a blob if I send blob…
Or am I completely wrong and there is a much better way to achieve that?

Finally I can send and read the image (.bmp) as an Int8Array like that:

int* embind_5(const emscripten::val &embind_5) {   
  std::vector<int> rv;
  const auto l = embind_5["length"].as<unsigned>();  
  emscripten::val memoryView{emscripten::typed_memory_view(l,};<void>("set", embind_5); 
  int* array = &rv[0];
  return array;