2 9 . 9 7 ▁frames / s ; ▁however , ▁this ▁practice ▁is ▁un common ▁for ▁most ▁commercial ▁film ▁releases , ▁which ▁provide ▁content ▁optimized ▁for ▁display ▁on ▁progress ive - scan ▁television ▁sets . ▁ ▁Altern ately , ▁the ▁content ▁can ▁be ▁encoded ▁on ▁the ▁disc ▁itself ▁at ▁one ▁of ▁several ▁alternate ▁frame ▁rates , ▁and ▁use ▁flags ▁that ▁identify ▁sc anning ▁type , ▁field ▁order ▁and ▁field ▁repeating ▁pattern . ▁Such ▁flags ▁can ▁be ▁added ▁in ▁video ▁stream ▁by ▁the ▁H . 2 6 2 / MP EG - 2 ▁Part ▁ 2 ▁enc oder . ▁A ▁DVD ▁player ▁uses ▁these ▁flags ▁to ▁convert ▁progress ive ▁content ▁into ▁inter la ced ▁video ▁in ▁real ▁time ▁during ▁play back , ▁producing ▁a ▁signal ▁suitable ▁for ▁inter la ced ▁TV ▁sets . ▁These ▁flags ▁also ▁allow ▁reprodu cing ▁progress ive ▁content ▁at ▁their ▁original , ▁non - inter la ced ▁format ▁when ▁used ▁with ▁compatible ▁DVD ▁players ▁and ▁progress ive - scan ▁television ▁sets . ▁ ▁Audio ▁data ▁▁ ▁The ▁audio ▁data ▁on ▁a ▁DVD ▁movie ▁can ▁be ▁PC M , ▁D TS , ▁M PE G - 1 ▁Audio ▁L ayer ▁II ▁( MP 2 ), ▁or ▁Dol by ▁Digital ▁( AC - 3 ) ▁format . ▁In ▁countries ▁using ▁the ▁P AL ▁system ▁standard ▁DVD - Video ▁releases ▁must ▁contain ▁at ▁least ▁one ▁audio ▁track ▁using ▁the ▁PC M , ▁MP 2 , ▁or ▁AC - 3 ▁format , ▁and ▁all ▁standard ▁P AL ▁players ▁must ▁support ▁all ▁three ▁of