Add option to shift a bird record

[JP-MCA]

I would like to propose a new feature.
Actually, I have a hearing impairment which does not allows my ears to catch anything upper than 6500 Hz.
I was not aware that there where so much birds singing in my garden with frequencies upper than 6500 Hz, but I had the prove by looking at birdnet-PI spectrograms.
What a pitty that I could not enjoy of those beautiful songs :-(

But, after having read the thread about bats detection, I come up with the idea that we could add a little tickbox near each spectrogram, to ask ffmpeg to shift frequencies down, which would be an easy manner to allows to ear some birds songs inaccessible for some of us.

In fact, the process is very easy, because we already have ffmpeg onboard of our RPI.
We just have to modify some Python scripts to insert following command for shifting frequencies down:

<pseudo-code>
if tickbox == YES
    ffmpeg -i the_original_recorded_file.mp3 -af "rubberband=pitch=3000/6000" the_shifted_recorded_file.mp3
endif
</pseudo-code>

and that's it. In this case, this is a division by 2 in frequency.

Could someone help me finding the best place to add this new feature in my birdnet-PI instance ?
I could then test it, and possibly send a pull request.

I think that this tickbox should be present near the PLAY button, so that we could activate it or not, whether we want to shift or not.

[ehpersonal38]

Hi @JP-MCA !

I think this is a fantastic idea - what a great way to utilize technology to make birding more accessible.

On the implementation of it, there are two options here:

1. Implement FFMPEG to pitch down all recordings as they are recorded, when a checkbox is set in Tools -> Settings
2. Implement this on the browser side using Javascript. We'll have to override the default browser audio player since that doesn't actually allow you to pitch mp3's down. A (lot) trickier but it's closer to the implementation you wanted originally, with the tickbox toggle button and all

[ehpersonal38]

I agree now that option 1 wouldn't work.

Okay your idea is certainly possible. The tick button would make an AJAX call to a php file that shell_exec()'s the ffmpeg command and returns the name of the new mp3 file, which then replaces the audio source's src. Were you interested in doing this yourself or if not I can probably have a go at it whenever I have free time

[croisez]

I have the capability to make it myself. I can try, yes.
As I am not used to the architecture of this project, as soon as I have it working, I could let you review my dev.

[croisez]

I have the capability to make it myself. I can try, yes. As I am not used to the architecture of this project, as soon as I have it working, I could let you review my dev.

sorry, I made a mistake at the first place, by using JP-MCA account, which is a profile I use for work. Croisez is my personal account.

[croisez]

Where could I discuss about technical issues ? I would like to get some clue about the best implementations. Could we discuss when you have time ? Could we use another channel to not ruin this thread ? => Teams, Whatsapp, ... ?

[ehpersonal38]

Sure, try joining this https://gitter.im/BirdNET-Pi/community