Detecting identical frames.

[hhhhhhhhhhhhhh5]

Is there a way to detect consecutive identical frames in footage inside AE? For example, I have a video with frames #100 and #101 that look identical down to every pixel. I would like to get this flagged in some way. So this would be a kind of the opposite to motion detection.

I understand that there are ways to do that with python scripts, etc. My question is specifically about doing this inside AE.

[Andrew Yoole]

There is no built-in process in AE for duplicate frame detection.

Lloyd Alvarez's script is the most common tool for this process thast I'm aware of.

https://aescripts.com/duplicate-frame-remover/

[hhhhhhhhhhhhhh5]

Thank you Andrew. This looks like a nice script, but I just need to flag the duplicate frames, not delete them. I wonder if that script uses some built-in function in ExtendScript that can compare frames.

[Roland Kahlenberg · Accepted solution]

You should be able to use the sampleImage() method. You'll need to think of an algorithm to work with.

[hhhhhhhhhhhhhh5]

Yes, sampleImage() is what I needed. Thank you!

[Roland Kahlenberg]

Please update us with your results when you're done.

BTW, if you're keen to build a Confidence Result, these can appear as Color Markers after the process. Hence, after the process (which can be assisted or automated), a user may visit the marked frames to double-check accuracy. The Confidence Result feature can also be used as a KPI to help increase accuracy during development.

[hhhhhhhhhhhhhh5]

Actually, that's what I've done. Because sampleImage() in not included in ExtendScript, I added a script to the video layer. It sets a text field in another layer to the sampleImage() output. Then, I run an ExtendScript that compares values in the text field frame-by-frame. When the difference is below a threshold, the script flags it and adds a comp marker for verification. Overall, it was not too difficult thanks to your advice!

[Roland Kahlenberg]

Great Minds think alike!  🙂
I'm happy you got it all sorted out.