I can 100% told you that... you MUST need 要另加解碼器... being the channel is difference.. and now.. NOT TV build-in 數碼廣播解碼器. that why you must need it later.
HD Rady... mean you can run 720p or 1080i resolution... if you not require too much... sure no problem... but if you want FULL HD... mean point to point... you TV MUST need 1920x1080 resolution.