How to identify telecine pulldown?
 

I think the answer to this question would be helpful for a lot of people.

I am having trouble "identifying" when video is telecine or pulldown. The only thing I go by is whether I know it was shot on film originally.

How do you tell just by looking at the video?

On these samples, the Mary Poppins clip is telecine - as Sanlyn has already pointed out. But what about this Blues Brothers clip?

Blues Bros. is interlaced. Open the file in Virtualdub and apply the built-in yadif deinterlace filter set for double frame rate, top field first. Advanced the video one frame at a time with the navigation icons in the lower left corner. With the yadif filter turned on, the left-hand input frame will show each frame as-is, unaltered, the output frame will show each field in succession, one field at a time. With each click of the frame advance button the output pane during motion will show a different image (look at the hands when they move, or look at Balushi moving). The images will play in the output pane as A-B-C-D-E-F and so on. A different image with each click indicates that the video is interlaced.

A duplicate frame with two clicks in a row during motion would indicate progressive frames. This would play as A-A-B-B-C-C-D-D and so on.

A duplicate clip for more than two clicks in a row interspersed with a sequence of only two dupes in a row indicates some form of pulldown. A typical pulldown would play as A-A-B-B-C-C-C-D-D-D-E-E-F-F-G-G-H-H-H-I-I-I or something similarly weird. Pulldown schemes consist of progressive frames interspersed with frames that appear as interlaced.

Try the old Neuron2 hmtl page (now removed from the internet, for some strange reason) for clues about how to "read" frame structures. Neuron2_How To Analyze Video Frame Structure.zip.

THANK YOU Sanlyn. Exactly what I was looking for.