Mix mp3 with mic input

[donnersm]

Hi, Maybe someone can push me in the right direction. I looked at the examples but I don't really see what i need.
Using an ESP32 and a I2S input and output, I want to mix an incoming input(mic) stream with an MP3 stream. So I will store mp3 files on SD and play them using the i2s output but before outputting the mp3 sound, it should be mixed with the input coming from mic.. like a karaoke machine.... on top of that would be great if i can manipulate the mic input....like with a vocoder... This would be used in a cosplay....like storm trooper uniform or robot... Anyone an idea what examples to look at or maybe even an idea how to mix those signals before output?

[pschatzmann]

There is a Wiki that covers Mixing!
I would try an input mixer and read from the microphone and from an EncodedAudioStream.

[donnersm]

Thanks, I found it