Hi. An interesting proposition. My first response would be - why use two separate systems?  If accurate registration between video and audio tracks is critical, why not record audio using the camera system, using either inbuilt or plug-in microphones? And then seperate out the audio track for analysis once you have captured both together on the once machine. 

My second question is (and I don't know the answer..) - is it realistic to attempt to capture one month of unattended video?  The file size is going to be huge isn't it?

I would be keen to hear from anyone else on these issues - I'm OK on audio recording, but no little about the video side of things.

Thanks, Carlos

Sam,

Thanks for that.  I don't know much about Rasberry Pi's but in terms of the basic concept, if you are running the video and audio from one device (and hence one clock), then the time sync should be sorted, shouldn't it?  The Pi has a stereo jack input doesn't it - so you could get a FEL Clippy stereo pair or something?  In terms of storage requirement, the audio (and video) file size will obviously depend on the quality you require.  For the sound files, the sample rate (= max frequency) is the critical issue for file size. A system that allows you to program your recording times and record ten minute (or whatever) file sizes would be needed - but presumably doable in Python?

Best of luck with the project.  Regards,  Carlos

Hello Sam
As per the previous posts, if recording audio and video on the same device then sync should not be a problem. If you do need a basic way to sync then try something along the same lines as used in the film industry: a clapper board. In your case this could be a small LED that flashes once per hour/day/week simultaneously with a short beep from a speaker (crude and probably not ideal if this is close to a nest) or automatic insertion of a "beep" into the audio recording.

More generally, have you had a look at CCTV and other remote surveilance systems ?  I am no expert on these but there is plenty of ready-made systems that handle a lot of issues such as power supply, data storage, weather-proofing etc. There should be some that record also audio though I would not expect this to be of sufficient quality for your purposes. This is definitely worth looking into as a repurposed tried-and-tested recording system is likely to perform better than a bespoke prototype.

Finally, if your site has mobile phone coverage then some form of frequent status message (if not a live data feed) will be invaluable to be able to react to any technical problems as they occur.

Good luck,
Joachim Neff

Sam/Joachim,

If looking at CCTV, then this book is probably worth a look:  https://pelagicpublishing.com/products/cctv-for-wildlife-monitoring

I haven't read it myself, but if it's as good as the others in the same series, then should be money well spent...

Ta, Carlos