For automatic transcription and chaptering, we'll need to know
exactly at which slide each section starts. This we already
had the count-slides.py script to count how many slides each
section had, and count the number of slides per part. The new
script does the same but also gives accurately the first slide
of each section.
count-slides.py will count the number of slides per section,
and compute size of each chapter as well. It is not perfect
(for instance, it assumes that excluded_classes=in_person)
but it should help to assess the size of the content before
delivering long workshops.
