[FFmpeg-user] using concat and duration?

[Tom Horsley]

The docs are a little light on the use of the 'duration'
directive in a concat filter.

If I want to explicitly give duration (to see if drifting
audio sync can be helped), what exactly does the
duration directive mean?

Is it the duration of the previous file?

Is it the duration of the next file?

Is it the duration of the concatenated files so far?

Is is another meaning I can't think of?

Anyone know?