[FFmpeg-user] Programmatically detecting 'busiest' parts of a video

[Rob Hallam]

Hi,

I'd like to programmatically detect the 'busiest' parts of a video- ie
the most visually active areas. I am leaving audio aside for the
purposes of considering this.

I figured it might be possible by looking at one / more of:

 - the bitrate for VBR videos -- a higher bitrate for a given segment
will tend to be associated with more activity (other things being
equal)
 - frame differences -- count pixels/blocks which differ, average over
a time segment
 - optical flow? (higher flow values = more activity) I'm not too
familiar with this

I'm not sure if there are better approaches, or if here is even the
right place to ask but figured the expertise of folks on the list
would be a good place to start.

Are there ways of doing this efficiently with ffmpeg or libav? I would
trade precision for speed!

Thanks for your time,
Rob