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

[Carl Eugen Hoyos]

2018-12-13 17:10 GMT+01:00, Robert Krüger <krueger at lesspain.software>:

> 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?

Just the mpeg specification;-)

$ ffmpeg -i input -c copy -f null -

Carl Eugen