code: public InputStream getAsStream() throws ProponoException {
          if (getContents() != null && !getContents().isEmpty()) {
              final Content c = getContents().get(0);
              if (c.getSrc() != null) {
                  return getResourceAsStream();
              } else if (inputStream != null) {
                  return inputStream;
              } else if (bytes != null) {
                  return new ByteArrayInputStream(bytes);
              } else {
                  throw new ProponoException("ERROR: no src URI or binary data to return");
              }
          } else {
              throw new ProponoException("ERROR: no content found in entry");
          }
      }
docs: Get media resource as an InputStream, should work regardless of whether you set the media
  resource data as an InputStream or as a byte array.