On Thursday 20 November 2008 15:15:57 Khelben Blackstaff wrote:
> Hello.
> I tried to transcode one of my dvds to h264 and noticed something
> which seems weird to me.
> If i choose the AC3 5.1 audio the movie is 6078 seconds long, while
> if i choose the DTS 5.1 audio the length is 5971 seconds. Despite
> the 2min difference, the movie seems whole.
> Is this normal ?
>
> AC3 output ("mencoder dvd://1 -oac copy -ovc copy -aid 128")
> ----------
> Video stream: 5927.506 kbit/s (740938 B/s) size: 4503956538 bytes
> 6078.720 secs 151971 frames
>
> Audio stream: 448.000 kbit/s (55999 B/s) size: 340356352 bytes
> 6077.792 secs
>
> DTS output ("mencoder dvd://1 -oac copy -ovc copy -aid 137")
> ----------
> Video stream: 5926.731 kbit/s (740841 B/s) size: 4424245234 bytes
> 5971.920 secs 151971 frames
>
> Audio stream: 768.000 kbit/s (95999 B/s) size: 573211758 bytes
> 5970.956 secs
>
> Also, i see in the mencoder output a "Skipping frame!" message
> every almost 2 seconds
>
> 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
