[FFmpeg-user] Get exact duration of an mpeg1 file

[Robert Krüger]

Hi,

is there a way to get the exact duration of a raw mpeg1 file using the
ffmpeg command line? For testing I created a 30 minute test file using
ffmpeg (using -c:v mpeg1video -f mpeg1video), then verified the duration
using VLC and mediainfo and it is indeed exactly 30 minutes long but ffmpeg
-i shows the file's duration as 00:00:04.98 after displaying this warning:

[mpegvideo @ 0x7fe212806000] Estimating duration from bitrate, this may be
inaccurate

Are there command line parameters to make it compute the exact size or is
this a design or implementation limitation?

Thanks,
Robert