problems solved.
moved antenna near to window solving signals fluctuate problem.
got video but no audio problem, solved by convert the file (ts format) to avi format (or other common formats)
I am surprised that you need to do that to get the signals in bukit batok. Either the draco antenna is awful or faulty or the signals still does not permeate deep into the hdb flats. I suspect it is the former since my amazon antenna is able to get a signal w/o placing it near the window at bukit merah.