for i in *.mkv; do
    ffmpeg -i "$i" -codec copy "${i%.*}.mp4"
done

Action - 1980 (tinto brass);Action.79.WD1080p.MemoriadaTV.Mini.mkv
Backstreet Dreams (1990);B4ckStreetD.90.WD1080p.MemoriadaTV.Mini.mkv
Biloxi Blues (1988);BiloxiB.88.BD1080p.MemoriadaTV.Mini.mkv
at close range (1996);CV95.BD1080p.MemoriadaTV.Mini.mkv
Desperate Hours (1990);DH.90.BD1080p.MTV.Yatogam1.Mini.mkv
Drugstore Cowboy (1989);DRugCowboy.89.BD1080p.MemoriadaTV.Mini.mkv
Showdown in Little Tokyo (1991);M.no.B.J4p4.91.Trial.MemoriadaTV.Mini.mkv
My Tutor (1983);MyTut0r.83.BD1080p.MemoriadaTV.Mini.mkv
Operation Pacific (1951);Operation.Pacific.1951.mkv
Pretty in Pink (original title);P.in.P.86.WD1080p.MemoriadaTV..Mini.mkv
The Pom Pom Girls (1976);PomPomG.76.BD1080p.MemoriadaTV.Mini.mkv
Romper Stomper (1992);SkinHe4ds.92.BD1080p.MemoriadaTV.Mini.mkv
I Can Make You Love Me (1993);StalkingLaura.93.DL1080p.MemoriadaTV.Mini.mkv
The Brotherhood of Justice (1986);TheBHofJ.86.TrialWEB-DL480p.MemoriadaTV.mkv	










Frauen für Zellenblock 9 (1978);W.in.CB.78.BD1080p.AFT.CaNNIbal.Mini.mkv
Private Moments (2005)