opencv 3.1.0 imread stunked, but imdecode is ok

Question

I'm using opencv 3.1.0, tried to read an image by imread, just like

Mat image = cv::imread("1.jpg");

but it stunked without any error message (performs like in an endless loop)

I changed imread to imdecode, like this

cv::Mat readimage(const char* filename)
{
  Mat image;
  FILE *file = fopen(filename, "rb");
  if (file == 0)
  {
    return image;
  }
  int len = 5000*5000*4;
  char *imgData1 = new char[len];
  int imgLen1 = fread(imgData1, 1, len, file);
  vector<unsigned char> vecImgData(imgLen1);
  memcpy(&(vecImgData[0]), imgData1, imgLen1);
  image = cv::imdecode(vecImgData,1);
  delete[] imgData1;
  fclose(file);

  return image;
}

Mat image = readimage("1.jpg");

and this try works well.

I just wonder what wrong with my picture? It's there something wrong when i use imread?