(Bad) Datas resampling when export from Motive

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barneygumble
Posts: 10
Joined: Wed Oct 14, 2009 2:28 am
Location: France, Bordeaux

(Bad) Datas resampling when export from Motive

Post by barneygumble » Mon Dec 14, 2015 8:40 am

Dear all,

I experience a real problem when I try to export tracked datas from Motive. Datas are tracked and labelled, and after a right click>export on the take, I create a c3d or csv file. Unfortunately, the exported datas does not correspond with the recording ones.
More exactly, it seems that a resampling is operated by Motive (in my case, resample at 120/100 Hz), even if the export parameters remain correct. Moreover, the exported sampling frequency (specified in c3d header) is not corrected.
For instance, if my recording is 1 second at 120Hz (with V120 trio), in the exported files my datas are sampled at 144hz (an event at frame 60 in motive will appear at frame 72 in the exported file), but the sampling frequency written in the header of .c3d files remain 120Hz. More, I only have 120 sample in the exported file, datas are trunckated. In the export parameters, if I asked for 144 samples, the full recorded second is exported (I have 144 samples at 144Hz). This phenomenon appears with release from 1.7 to 1.9 (I did not test the other one).
Does anyone else experience this problem? Is there a bug to fix here?

Thanks
Etienne

steven.andrews
NaturalPoint Employee
NaturalPoint Employee
Posts: 591
Joined: Mon Jan 19, 2015 11:52 am

Re: (Bad) Datas resampling when export from Motive

Post by steven.andrews » Mon Dec 14, 2015 10:48 am

Hello Etienne,

Thank you for reaching out to us regarding your export issue.
I am not sure if I understood all of your information. Is it correct that you have tested in Motive 1.7 and 1.9, but you have not tested in 1.8?

In which version was your data recorded? Have you tried recording in 1.9 if you are also exporting from 1.9?

Motive 1.7 did have an issue in which Take meta data was sometimes being written incorrectly. You might try selecting the Take and looking through the properties to determine if the capture rate and duration both appear to be correct.
If you continue to experience an inconsistency when you both record in and export from 1.9, we would like to know this. If you could also open a support ticket with us at help.naturalpoint.com, we would like for you to submit a short Take to us so we can look at this on our end.

Best regards,
Steven
--
Steven Andrews
OptiTrack | Customer Support Engineer

barneygumble
Posts: 10
Joined: Wed Oct 14, 2009 2:28 am
Location: France, Bordeaux

Re: (Bad) Datas resampling when export from Motive

Post by barneygumble » Tue Dec 15, 2015 12:50 am

Thanks for this reply. It is right that I made the recording with Motive 1.7, I will update the version on the laptop used for the data acquisition and test the results.
Note that on 1.9 beta, during the tracking process, the right click "unlabel Marker(s)" on blue defined signal part does not have the same behavior as before, and we don't understand how it works now.

Best regards
Etienne

steven.andrews
NaturalPoint Employee
NaturalPoint Employee
Posts: 591
Joined: Mon Jan 19, 2015 11:52 am

Re: (Bad) Datas resampling when export from Motive

Post by steven.andrews » Tue Dec 15, 2015 10:09 am

Hi Etienne,

I am not sure I understand what functionality you are referring to. Could you describe, step--by-step, what you used to do and what the result is in the new builds of Motive?

If you have any screenshots that display what you are trying to do, this may help as well.

Thanks,
Steven
--
Steven Andrews
OptiTrack | Customer Support Engineer

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