1 Topic by Chas Tennis (edited by Chas Tennis 2018-06-28 20:47:05)

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My application is high speed video of tennis strokes.  (I have not used Version 8.26)

I use the countdown feature in Version 8.25 and it is great.  It is especially useful for side-by-side tennis stroke comparisons with setting "0" the time of racket to ball impact for each video.  The entire time line of the stroke motions is labeled.  This would apply to many sports: striking, throw release, kicking impact, etc.

But the countdown feature ends at 0 time.  It would be a big improvement if the countdown feature counted down to 0 displaying negative time and then counted past 0 displaying positive time. 

It would seem that this could be done all from frame "0" for side-by-side videos by coordinating the two videos on a single frame and using the frame rate data.   For side-by-side videos with identical frame rates probably only one time display is needed.

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There is also a procedure required to set up the countdown that might be more direct. I have difficulty remembering this procedure. Perhaps a maximum time could be set prior to frame "0".  Does it have to count from the first frame of the video "segment"? and not back from frame "0". Are the frames always counted for each segment video?

8.25 Procedure to set up countdown mode.  From 2016 Nov 28 post by Joan in Version 8.25 thread.

"Stopwatch in countdown mode within the segment prior to the synchronization point should work. However the countdown mode only works if the stopwatch has a well defined range, specified by start and end points.

I think in your case you want to do the following:

    Go to the begining of the segment.

    Add the stopwatch object on the first frame.

    Right click the stopwatch and choose "Start"

    Move forward in time up to the synchronization point (shortcut: F8).

    Right click the stopwatch and choose "Stop".

    Right click the stopwatch again and choose "Countdown"."

2 Reply by joan

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I agree it would be interesting and useful to have this feature with negative time.

Right now I'm not satisfied with how the stopwatch works and at some point I'll attempt to improve it.

To better understand the way it works internally consider that it has a "visibility start" and "visibility stop" and it has a "counting start" and "counting stop". The "counting" segment is always nested inside the "visibility" segment. The countdown mode is simply "inverting" the value of the counting.

The shortcomings at the moment is that you can't move the "visibility start" point, so once you put a stopwatch on the video it can never be moved back to an earlier point. And you can only move the "visibility end" point backwards in time with the "hide" menu.

I am trying to think of a way to make it more flexible.

The system you describe with the countdown going on in the negative makes me think that this would be better suited for a new tool that would let you set a single point in time, rather than a segment in time.

There is also another time tool that is missing, one that allow the measuring of several segments in a row, with or without gaps between them.

Another interesting one would be a "cyclic timer" tool that counts to a given time and auto-resets and starts counting again.

3 Reply by joan

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Thinking of it a bit more, key images are the best way to set time marks. So it would be interesting to be able to right click on a key image and say "set as time origin", forcing the timing information to be relative to this point, like for the synchronized videos. Then a simple tool showing the current time would fill the need. It seems all the mechanisms are already existing. Except for the remaining UX difficulty to be able to flexibly set start/end visibility points.