How to get video duration in seconds?

Question

How can I get video duration in seconds?

what I've tried:

ffmpeg -i file.flv 2>&1 | grep "Duration"
  Duration: 00:39:43.08, start: 0.040000, bitrate: 386 kb/s


mediainfo file.flv | grep Duration
Duration : 39mn 43s

this what close, but it's not so accurate, 2383 is 39.71 minutes

    ffmpeg -i file.flv 2>&1 | grep "Duration"| cut -d ' ' -f 4 | sed s/,// | sed 's@\..*@@g' | awk '{ split($1, A, ":"); split(A[3], B, "."); print 3600*A[1] + 60*A[2] + B[1] }'
2383

Answer 1

There is a better, faster and low CPU/HD footprint solution, just with mediainfo without relying into awk:

mediainfo --Inform="General;%Duration%" input.m4v