Creature Capture | Variable Video Capture Length Code & Testing, Frame Rate Issues

So I’ve been working a lot in the past day in ironing out part of the night side loop (loop 3 in this diagram). Basically, it starts recording based on an input from a sensor and continues to record until these inputs stop occurring.

My test code looks like this

The interesting functions at work here are the following:

FilmDurationTrigger() Takes the period of time that will be filmed, in this example, it’s 5 seconds just to conserve time, but in application it will be 20 seconds. This code will pause for the input time, and continue to be paused upon inputs from GetContinueTrigger(). This delay allows the code to continue filming until there are no inputs.

In this example, GetContinueTrigger() returns a Boolean if a random event occurs, but in application it will return a Boolean based on the status of a motion detector.

I ran two tests, both of them produced separate results. The first one created a 10 second long video:

And the second created a 15 second long video:

These two test shows that variable capture length functionality works! As a note, the actual times on the output video varies from the amount of time that it’s designed to record for. This is because the variable frame rate nature of the video coming out of the camera module, it causes the videos to come out a little short, but they still contain all the frames of the amount of time desired to record, just scaled slightly by frame rate error.

Creature Capture | Stopping Raspivid After a Non-Predetermined Time

One of the biggest problems with the built in commands for using the Raspberry Pi Camera module¬†is that you can’t stop a recording after an unknown time. You can record for a given number of seconds and that’s it. I have attempted to solve this problem by backgrounding the initial record process with a time of 27777.8 hours (99999999 seconds) when it’s time to stop recording, the process is manually killed using pkill.

Here is a test of my code, which I’ve called CameraModulePlus (written in python) which takes two videos, one for five seconds, and one for ten seconds, with a 10 second delay in between.

Here is a result of the 5 second duration test:

Here is a result of the 10 second duration test:

As you can see, it works pretty good for how barbaric it is. The full class for CameraModuleVideo can be found here.¬†In the future, I’d like to encode a lot more data into the CameraModuleVideo class, things about time etc. Also I would like to monitor available space on the device to make sure there is enough space to record.

Creature Capture | Project Declaration & Top Level Flowchart

I’ve decided to embark on a video surveillance project! My family lives in a very rural part of the US, and constantly hear and see evidence of animals going crazy outside of my home at night. The goal of this project is to hopefully provide some kind of insight as to what animals actually live in my backyard.

Ideally, I want to monitor the yard using some kind if infrared motion detector. Upon a motion detection, an IR camera assisted by some IR spotlights would begin filming until it has been determined that there isn’t any more movement going on in yard. These clips would then be filed into a directory, and at the end of the night, they would be compiled and uploaded to YouTube. This video would then be sent to the user via email.

I’ve created the following flowchart to develop against as I begin implementing this idea.

I’ll be using a Raspberry Pi to implement this idea, a few months back I bought the IR camera module and haven’t used it for anything, this would be a good project to test it out.

There are a few hurtles that I’ll have to cross in order to make this project a success, like most groups of problems I deal with, they can be separated into hardware and software components.

Hardware

  1. Minimize false positives by strategically arranging motion detectors
  2. Make sure IR Spotlights are powerful enough to illuminate area
  3. Enclosure must be weatherproof & blend in with environment, Maine winters are brutal.

Software

  1. The Pi doesn’t have any built in software to take undetermined lengths of video.
  2. Must have a lot of error catching and other good OO concepts in order to ensure a long runtime.

I’ve actually come up with a routine for solving the first software problem I’ve listed, hopefully I’ll have an example of my solution in action later tonight.

Ideally, this project will have a working implementation completed by May 21, which is 7 days from now.