code: private static long getFileSizeFromUrl(String url) {
          if (!url.toLowerCase().startsWith("http")) {
              return -1;
          }
  
          final Request request = new Request.Builder().url(url).head().build();
          long respLength = -1;
          try (Response response = MVHttpClient.getInstance().getReducedTimeOutClient().newCall(request).execute();
               ResponseBody body = response.body()) {
              if (response.isSuccessful())
                  respLength = body.contentLength();
          } catch (IOException ignored) {
              respLength = -1;
          }
  
          if (respLength < 1_000_000) {
              // alles unter 1MB sind Playlisten, ORF: Trailer bei im Ausland gesperrten Filmen, ...
              // dann wars nix
              respLength = -1;
          }
          return respLength;
      }
docs: Return the size of a URL in bytes.
  
  @param url URL as String to query.
  @return size in bytes or -1.