GoPro: Filtering Out Whistling From Driving Videos [TCE #0449]
5Quite a different video, so skip if you have no interest in this (obviously).
I have noticed an annoying issue when capturing driving footage using my GoPro HERO 11 for my @BrfffTravels channel. I'm using a suction cup mount on my car roof and usually a USB-C cable for power running back into the car.
At high speed (110km/hr) there is a noticeable whistling sound in the video that can't easily be removed in the simple editing software I use (Apple's iMovie).
I think the whistling comes from the suction cup mount as it is still there when I don't use the USB-C cable. Annoying.
It suddenly occurred to me today that maybe I could identify the frequency using Audacity, and then apply a filter. As the GoPro generates MPEG files you need to ensure that you have FFmpeg installed in addition to Audacity.
I simply dragged the video file into Audacity (11GB? No problem!), went to [ANALYSE] then [PLOT SPECTRUM] ... and it was immediately obvious ... there was a spike in energy at 3554Hz.
Next, I went to [EFFECT] then [EQ AND FILTERS] then finally [NOTCH FILTER]. Gave it 3554Hz and finally, after annoying me for months, the whistle was gone. Export the file as an MP3.
Now in iMovie I just had to detach the audio from the video & delete it, then import the filtered MP3. Of course, you can apply other effects to reduce wind noise, etc.
Maybe there is a better way of doing this ... ? Like, maybe using proper video editing software?
Thought this might be of vague interest to someone. That's all.