code: def timestr(msec):
      
      sec = float(msec) / 1000
  
      hours = int(sec / 3600)
      sec -= hours * 3600
  
      minutes = int(sec / 60)
      sec -= minutes * 60
  
      output = "%02d:%02d:%06.3f" % (hours, minutes, sec)
      return output.replace(".", ",")
docs: Convert a millisecond value to a string of the following
      format:
  
          HH:MM:SS,SS
  
      with 10 millisecond precision. Note the , seperator in
      the seconds.