Jun 8 2013
Christophe Caberlon has a special way of conducting this first step: at 6X normal speed. When reviewing videos with the operators who have been recorded, he has found that accelerated motion has the effect of drawing attention to the activities that consume the most time, as the ones that do not are filtered out. If the operator spends the majority of the time walking back and forth to a shelf to pick parts, a fast-motion viewing of the recording makes it dramatically obvious and compelling, making the operator eager to help improve the process. After trying various 2X, 4X and 8X, he has found that the 6X ratio of acceleration works best for this purpose.
When Christophe told me about this, it reminded me of a scene in the movie The Hunt for Red October, in which sound is used the same way. Jonesy, the sonar operator in the American submarine tracking the soviet submaring Red October, has just heard the sound of the propellers disappearing when the Russian boat turned on its “silent” propulsion system. But he still heard a vague rumbling. The analysis software categorizes this sound as magma displacement, but the sonar operator believes that the sound is made by the submarine. To convince his captain of that, he plays the recording at 10 times the speed, which turns the rumbling into a rythmic “tac tac tac” characteristic of a human artifact and not magma displacement.
The idea of watching the video in fast motion is that, by filtering, it lets you see patterns you would otherwise miss. The same is true of slow motion, but fast motion has the advantage,… of being fast. You wouldn’t want to review an entire 1-hour video in slow motion, but you may do it in a few excerpts as part of the detailed analysis we will go into in a coming post.
Of course, the idea of reviewing a video in fast motion is more interesting if you can actually do it, and the most common video players around don’t let you run at 6X. I tried the following:
- Quicktime V. 7.7 through “A/V controls” lets you run videos at speeds up to 3X.
- Windows Media Player does not let you change the speed.
- Real Player lets you change speed by powers of two by pressing Ctrl-Shift-F4, but the resulting accelerated videos are not watchable.
- VLC media player lets you use any speed up to 4X, and powers of two beyond, up to 32X.
Among video editors, Windows Live Movie Maker lets you change speeds, but Google’s Picasa 3 doesn’t. For Windows Live Movie Maker, it is again in powers of 2.
In video annotation software, ANVIL doesn’t do fast-motion, but Timer Pro does. To view a video in 6X in Timer Pro, you click on the Video tab and set the speed to 12. The video then plays at the right speed but the a wrong aspect ratio. If, however, you click on the Comparison tab, you can view at 6X normal speed and with the correct aspect ratio, albeit in a small window that you cannot adjust.