when i download a movie in torrent and i play the movie i download and it placed you need to download a codec . i downloaded a codec pack and it is not working , not played but the duration of the movie i download is 2 hours.. please help..... 
just download a video converter to decode the video and convert it in some common used video formats.
the downloaded movie may not be natively supported by your media player, it’s better you could transcode it to the accepted video/audio file for your player.
No need of DVD ripping tools, but need a video converter to convert your downloaded movie to popular video formats for playback, such MP4, AVI, etc. By the way, the media player would better be handling most of the formats.
Recommend converter: MacX Video Converter Pro
Recommend player: 5KPlayer