Realtime frequency peak detection about fftea HOT 4 CLOSED

Your overall approach sounds fine. Step one is definitely to verify the data you're getting from mic_stream. You definitely shouldn't be seeing NaNs, so I suspect the mic data is bad.

Coincidentally I recently worked on a project that streamed microphone data through STFT, and I ran into similar issues. To verify the microphone data you'll need to find some way of playing the audio. In my case I saved the audio chunks to WAV files on my phone, then copied then to my computer so I could look at the sample data directly.

I also started out my project using mic_stream, but I ran into all sorts of issues. For example, I was using 16-bit PCM and I found that the 2 bytes in each sample were the wrong way around, so I had to manually decode it. After a lot of troubleshooting I eventually got the audio to sound ok, but there was a weird clicking sound in the chunks. Turned out that the first few samples in each chunk I received from the microphone were 0. At that point I gave up and switched to flutter_audio_capture.

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Hey, thank you so much for your helpful advice!
I was able to get non-NaN values by using FFT instead of STFT, as I only needed to detect peaks FFT is sufficient. Your suggestion about using mic_stream was also very useful. I switched to using flutter_audio_capture and it's now working perfectly. Thanks again!

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@Clon1998 glad you got it working. I'm a bit concerned that you were getting NaNs with STFT but not FFT though. Sounds like a bug in my code. Are you able to figure out the input data that does this and post it here?

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@Clon1998 glad you got it working. I'm a bit concerned that you were getting NaNs with STFT but not FFT though. Sounds like a bug in my code. Are you able to figure out the input data that does this and post it here?

I need to double check. But I think I also got NaN values while using the 32 BIT Float PCM encoding. After switching to 32 Bit PCM (int) I got normal values.

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