On Thu, 20 Nov 2008 15:26:34 +0100 Nico Sabbi <Nicola.Sabbi at poste.it> wrote: > > > > Is this normal and why it is happening ? > > mostly, and mostly not (it's the usual black magick at work > when playing mpeg streams). > > You should rely on the data reported by -identify to get the exact > video duration, at least when playing dvds Thank you for replying so quickly. Both "mplayer -identify -frames 0 dvd://1 -aid 128" and "mplayer -identify -frames 0 dvd://1 -aid 137" report the following. ID_DVD_TITLE_1_LENGTH=6078.840 ID_LENGTH=6078.84 So, i guess the correct duration is 6078 seconds, but when mencoder finishes the transcoding the resulting file has 6078 secs if it has ac3 audio and 5971 if it has dts.