I need to get a total count of JPG files within a specified directory, including ALL it's subdirectories. No sub-sub directories.

Structure looks like this :

dir1/
2 files  
   subdir 1/
       8 files

total dir1 = 10 files

dir2/ 
    5 files  
    subdir 1/ 
        2 files  
    subdir 2/ 
        8 files

total dir2 = 15 files

I have this function, which doesn't work fine as it only counts files in the last subdirectory, and total is 2x more than the actual amount of files. (will output 80 if I have 40 files in the last subdir)

public function count_files($path) { 
global $file_count;

$file_count = 0;
$dir = opendir($path);

if (!$dir) return -1;
while ($file = readdir($dir)) :
    if ($file == '.' || $file == '..') continue;
    if (is_dir($path . $file)) :
        $file_count += $this->count_files($path . "/" . $file);
    else :
        $file_count++;
    endif;
endwhile;

closedir($dir);
return $file_count;
}