Duration Innaccuracies

[mikebinz]

Hi

I'm running Win7 using Exif 10.94 with a variety of command lines.

I have a pretty large collection of Media Files (Movies, Docos etc) in a variety of Formats and I'm using Exiftool to update the Durations of all these Files (amongst other fields)

I've encountered two different problems; output is available as expected, but is incorrect in the following 2 cases;

1) for .ogv files the ExifTool Output Duration is always about 7 times longer than the Actual Duration (but only about 7x; it's not consistent)

2) for a very few .avi files the ExifTool Output Duration is way shorter than the Actual Duration (there doesn't seem to be any set ratio, but all the cases I've found are less a 1 minute).

I haven't found any other anomolies, having checked about 5,000 files

Various Media Players (eg VLC Media Player) report the Duration of all these problem Files correctly

Could this be due to Meta Tags being corrupt or inaccurate for these files, and if so can ExifTool or any similar Utility be used to report the Actual Duration reliably?


Congratulations on this project; it's a credit to all involved and great to see enthusiastic Open-Source Programmers who are interested in developing useful tools without comodifying them


regards


mikebinz

[Phil Harvey]

Hi Mike,

I'll look into the OGV problem, but any duration calculated from the metadata will be approximate only.  ExifTool doesn't parse the audio/video data itself, and I think this is the only way to get an accurate value.  See the Duration tags in the Composite tags documentation for details on what metadata tags ExifTool uses in these calculations.  I would be happy if you can suggest any better techniques.

- Phil