Solved

Capture video before and after a trigger

Posted on 2011-03-25
4
300 Views
Last Modified: 2013-11-13
I am looking for ideas on how to achieve the following:

1. A video camera streams feed continuously, but it is not recorded
2. An event occurs - e.g a door is opened, triggering a switch
3. The video from 30s before the event and up to 30s after the event is captured and saved to disk
4. The system waits for any subsequent events and repeats the process.

The video stream is going to be VGA standard at 25fps - any hints?
0
Comment
Question by:cquinn
  • 2
4 Comments
 
LVL 38

Expert Comment

by:lherrou
ID: 35218241
cquinn,

There's a lot of motion detection software out there, and the state of the art is pretty good. Do you have to have a physical trigger? Because that gets a lot more complicated.

Cheers,
LHerrou
0
 
LVL 15

Author Comment

by:cquinn
ID: 35219932
It has to be a trigger, as there will already be a lot of motion in the frame, so motion detection is out.

The trigger may not be physical - it could be generated form a smart phone for example - imagine it is a sport being played and we wish to record a significant event such as a home run, or touchdown, and the event is triggered by an onlooker - by the time they signal the event, it has already passed, which is why we need to timeslip back up to 30 seconds to capture the build up to the event, the eevent itself and its immediate aftermathy.
0
 
LVL 5

Accepted Solution

by:
KenIBrown2 earned 250 total points
ID: 35244874
It seems to me that the problem is finding some software that can buffer 30s video but in some temp storage, and then on demand (and also say 30s later after capturing another 30s,) commit that 60s temp storage to a single file that is somehow tagged with the time/date say, & then saved as a 'proper' file.

How about finding an app that can save video to named files in (say) 1s chunks. Keep track of these chunks in a circular buffer style, and when your event is triggered ( or rather 30s later) : flag for the set of 60 x 1s-chunk-files to be copied out to some say folder whos name represents the trigger time.

...Then offline concatenate the 60 sep files into one...

I can only think of MaxMSP/Jitter that could actually do this in my limited experience.


0
 
LVL 15

Author Closing Comment

by:cquinn
ID: 35308632
We are going to use ffmpeg for the splicing and slicing, after capturing in one minute chunks.
0

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

Suggested Solutions

HOW TO: Upload an ISO image to a VMware datastore for use with VMware vSphere Hypervisor 6.5 (ESXi 6.5) using the vSphere Host Client, and checking its MD5 checksum signature is correct.  It's a good idea to compare checksums, because many installat…
This article explains how to prepare an HTML email signature template file containing dynamic placeholders for users' Azure AD data. Furthermore, it explains how to use this file to remotely set up a department-wide email signature policy in Office …
Polish reports in Access so they look terrific. Take yourself to another level. Equations, Back Color, Alternate Back Color. Write easy VBA Code. Tighten space to use less pages. Launch report from a menu, considering criteria only when it is filled…
This video shows how to remove a single email address from the Outlook 2010 Auto Suggestion memory. NOTE: For Outlook 2016 and 2013 perform the exact same steps. Open a new email: Click the New email button in Outlook. Start typing the address: …

707 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

12 Experts available now in Live!

Get 1:1 Help Now