programmatically invert sound output polarity on raspberry?

[Ramses]

Is there an easy way to programaticaly invert the sound output polarity on a raspberry board?

I mean programmatically changing the positive to negative, and negative to positive few minutes. then programmatically turn it back to normal..

Thanks!

[Fred vS]

The easier way is to multiply each sample by -1.

If your samples are stored into a array, just do:

Code: Pascal  [Select][+][-]

1. for x:=0 to length(datasamples)-1 do
2. datasamples[x] := datasamples[x] * -1;

[Ramses]

Thanks for your reply!

But for now, i dont play the sound from my application, (I have not specify it in my first post: my mistake)

So let say that another external application is playing something on the speaker, and i want to programmatically invert sound output polarity on raspberry pi 3 board, is there an easy way to do this?

(Actually the way i found to invert my polarity is to use a relay and turn the relay on to invert the polarity, this work great, but i wanna know if i can do it from my code to save space in my project box, and to use less hardware as possible...)