replay recorded camera footage in slow motion

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nizer

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Dec 5, 2017, 10:13:31 PM12/5/17
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Anyone know how to playback video from a USB camera coming into QLab in slow motion.

I assume I will end up using applescript to Quicktime and use QT's built in slow motion abilities.

Steven Sokulski

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Dec 6, 2017, 1:16:14 PM12/6/17
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When you say recorded camera footage, do you mean that the action will take place that the camera is recording, and then play back in slow motion?

You can control QuickTime with AppleScript to record a camera input as part of a set of Script cues. Then load that video file to a Video cue, also using AppleScript.

If you can shed some more light on the details of your goal, the community might have an alternative answer.

Mark Nizer/Neisser

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Dec 6, 2017, 4:40:25 PM12/6/17
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Thank you for the reply. Yes I want to record live during the show, then go back for some “instant replay” in slow motion in certain parts of the video.

I don’t see a applescript to make Quicktime playback in slowmo, but there are some keyboard commands “KL" to slow it down. I may be able to pull that of with Quickeys.

Thoughts?
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Mark Nizer
When the Entertainment Matters



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micpool

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Dec 6, 2017, 4:45:02 PM12/6/17
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I'm clearly missing something here.

Why don't you just play the recorded file in QLab and use the rate control

Mic

Mark Nizer/Neisser

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Dec 6, 2017, 4:50:52 PM12/6/17
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Rate control? What is that?

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Mark Nizer
When the Entertainment Matters


micpool

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Dec 6, 2017, 4:50:55 PM12/6/17
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On Wednesday, December 6, 2017 at 9:40:25 PM UTC, nizer wrote:

I don’t see a applescript to make Quicktime playback in slowmo, 

tell application "QuickTime Player"

set the rate of the front document to 0.3

end tell

 

micpool

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Dec 6, 2017, 4:55:20 PM12/6/17
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On Wednesday, December 6, 2017 at 9:50:52 PM UTC, nizer wrote:
Rate control? What is that?

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Steven Sokulski

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Dec 6, 2017, 6:58:36 PM12/6/17
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I too would use rate control in QLab once you load the file.

Just change the file for a Video cue. Then the geometry, surface, and speed will be inherited from the cue.


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nizer

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Dec 10, 2017, 4:56:12 PM12/10/17
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I have made a lot of progress with this.

My goal is to have "markers" for start times of a video to be noted (when I drop. Triggered via a smart phone running Lemur given to a audience member) for later playback in slow motion.

My issue is figuring out how to record the list of markers and then convert them to the proper format for use as start times.

I put some comments in the script where I am getting stuck.

I have been playing with this script:

tell application id "com.figure53.QLab.4" to tell front workspace 
set myDropTime to action elapsed of cue 9
--Cue 9 is a still image in a video cue that starts when I start the routine
--Getting a strange number here. They seem to be going down? (0.1754570330003844)
 
set myDropsList to {}
set end of myDropsList to myDropTime
set the q name of cue "drop1" to item 1 of myDropsList 
        set the q name of cue "drop2" to item 2 of myDropsList 
        set the q name of cue "drop3" to item 3 of myDropsList  
end tell

Then to replay for review in slow motion this:

tell application id "com.figure53.QLab.4" to tell front workspace
set myFirstReplay to the q name of cue "drop1" as number
        --need to figure out how to convert the times collected in the previous script to meaningful times here. 
say myFirstReplay
set start time of cue "8" to myFirstReplay
set end time of cue "8" to myFirstReplay + 1
end tell 

micpool

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Dec 10, 2017, 7:59:57 PM12/10/17
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Cue numbers are strings so you want cue "9".  (cue 9 will be another cue somewhere in the workspace)

I don't understand the rest of your script, every time it runs you are setting a list to empty and adding a value to the end of it but then expecting to find 3 items in it.

If I was scripting this project my starting points would be the following:

I assume you are having the audience member with the remote hitting the button 3 times.

run a script that is triggered each time the button is hit and store the hit number somewhere like in the notes of the cue incrementing it each time.

Set the load time of 3 load cues to the time elapsed at each trigger and target these cues to the placeholder video cue you are going to file target to your video recording.

Note you are always using seconds so no conversion is necessary between the time elapsed and the values you store in the load cues.

Except, if you have the rate set in the video cue to .5 you will need to adjust your load times 

e.g if your video in real time was marked at 10s you will need a load time of 20s at rate 0.5 etc.

Mic

nizer

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Dec 11, 2017, 2:20:40 PM12/11/17
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Thank you so much. I had the wrong cue info because of the cue "9" vs cue 9 mistake. I had trouble putting stuff into the notes field and retrieving it so I just plugged in the numbers right into the Load Cues.

Here is a working version. Love your thoughts and tweaks.

you will need to put in audio cue and link the playback video.
slow motion playback.qlab4
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