pts_time is always "nan", never an actual time in seconds

[True_cidril]

I'm using following command used in PowerShell to get scene detection to give me image thumbails of each scene and I also write information about each thumbnail to file (the "metadata=print:file=$workingFolder/$sceneInfoFilePath" part).

..\ffmpeg -i $originalVideo -vf  "select='not(mod(n,10))',select=gt(scene\,$sceneDetectionTrashHold), scale=$thumbnailSize, metadata=print:file=$workingFolder/$sceneInfoFilePath" -vsync vfr $workingFolder/scene%03d.png

On my local computer it all works as I expected and what I get in the printed txt file is the following:

frame:0    pts:190000  pts_time:7.6
timecode=00:00:07:15
lavfi.scene_score=0.269723
frame:1    pts:820000  pts_time:32.8
timecode=00:00:32:20
lavfi.scene_score=0.374757
frame:2    pts:1050000 pts_time:42
timecode=00:00:42:00
lavfi.scene_score=0.391074
...etc...

where you can notice the pts_time contains a float value.

But on my server (so on a different computer, a virtual machine in fact), where I want to use this I get the following for the same file and with the same script used:

frame:0    pts:190000  pts_time:nan
timecode=00:00:07:15
lavfi.scene_score=0.269723
frame:1    pts:820000  pts_time:nan
timecode=00:00:32:20
lavfi.scene_score=0.374757
frame:2    pts:1050000 pts_time:nan
timecode=00:00:42:00
lavfi.scene_score=0.391074
...etc...

As you can see the pts_time:nan is always "nan". I spent like a day on this and I have no idea why there is nan and not an actual time in seconds. It should be just pts/1000/framerate. Which I can rewrite of course to have it this way, but I would really like to figure out why ffmpeg is not able to calculate the pts_time. Any suggestions/tips?

Any help appreciated! Thanks!

[davexnet]

I don't know either, but some info here
http://underpop.online.fr/f/ffmpeg/help/select_002c-aselect.htm.gz