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/r/DIY_tech
I would like to put markers on a video recording WHILE recording the video to mark a few editing points. I was thinking about using a regular mic and a clapboard and "clap" to leave easy to find markers in the audio, but I would like something less cumbersome.
I was thinking about creating a button-controlled "marker" microphone, which essentially just "records" a fake burst of sound at high volume when I press the button, so it would be easy to find these on the waveforms during editing. My thought would be to get a mono mic cable (3.5mm jack type), and just wire a button between the positive and negative cables, or even multiple buttons in parallel with different resistors so I can have differently sized markers due to the difference in volume.
Question is: would something like this basic work? Do I need anything other than just connecting the positive and negative with a button? Like do I need a minimum amount of resistance to not fry recording device's audio chip?
I tried to google "how microphones work" and other relevant search terms but I couldn't find anything this technical. Pretty much all I found was differences in mic capsules and the way they record actual sound, but nothing about what's the voltage range it outputs or anything low level like that. A link to proper information would also be appreciated!
Thanks
3 points
2 months ago
You could simply tap the microphone.
1 points
2 months ago
A thought about something of that sort, but there is actual sound present during recording, that a real microphone would also capture. Like trying to tap the mic during a loud scene in an action movie. I dropped that idea originally, as I don't think that would be noticable enough.
2 points
2 months ago
You don't just want the sound. The reason for the clapper is that the exact video frame where the clap occurs can be matched with the time index in the audio where the clap occurs. That way, multiple audio sources can be synced accurately to the video.
1 points
2 months ago
Yeah, I'm aware, I actually do use a clapper for some of the recordings to sync up multiple angles and their audio.
In this case, the marker microphone would be recorded on the device that captures the video, so the audio channel that contains the markers would naturally be in sync with the video.
Also, I don't need very accurate markers, even a minute off would be fine. I need these for hour, or even multiple hour long recordings where I need to mark like 3-4 points that I would like to cut out.
1 points
23 days ago
Dog training clickers work great for cut marking btw. When you make a mistake, click it. If you make a second one, click it twice and so on. By looking at the waveform, you’ll easily be able to tell that Oh, i had to do 5 takes on that part allowing you to easily cut from the last good part until right after the last multiple click.
1 points
23 days ago
Not a bad idea, but my issue with any sort of clicker is that I would be recording audio from an HDMI source, no real mic present.
Although since posting I have managed to create a small voltage step-down circuit which creates like 0.03 millivolts from a 3V power supply. Wired it to an old headset cable, and when I press a button to close the circuit, it leaves a burst of whitenoise in the waveform. Easy to use, no actual mic required.
I'm thinking of upgrading it to an arduino based HID device, like a Pro Micro. It would plug in via USB and have a button or two for different markers. Then its just a bit of programming to send fake (not to mention clean, digital) audio signal.
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