Error: cannot set channel count for microphone (Invalid argument)

[blogdemoi]

Hi,

I installed Picam on a Raspberry Pi 3. The camera is a Pi camera and the microphone is a usb "PlayStation Eye". When I run ./picam --alsadev hw:1,0 I have this error:

picam ./picam --alsadev hw:1,0
error: cannot set channel count for microphone (Invalid argument)

picam arecord -l
List of CAPTURE Hardware Devices
card 1: CameraB409241 [USB Camera-B4.09.24.1], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0

What can be wrong?

Thank you for any suggestions.

[iizukanao]

Hi, please follow the guide below to create an ALSA virtual device that mixes 4 microphones into one, then use that virtual device (cap) with picam.
https://www.cnx-software.com/2019/08/30/using-sony-ps3-eye-camera-as-an-inexpensive-microphone-array/

[blogdemoi]

Thank you. I followed the guide you mentioned. However now I have:

picam ./picam --alsadev hw:1,cap
error creating state dir (./state): File exists

[iizukanao]

I think the state in your filesystem is a broken symbolic link. Fix the symbolic link or remove it with rm state.

[lukaszgielecinski]

I have a 2xElectret condenser microphone and to fix the same problem I added /etc/asound.conf file with the following content:

pcm.channelsum {
 type plug
 slave {
  pcm "hw:1,0"
  channels 2
 }
 route_policy sum
}

I rebooted pi and I use it like that:

./picam --alsadev channelsum

[blogdemoi]

I have a 2xElectret condenser microphone and to fix the same problem I added /etc/asound.conf file with the following content

Thank you, I haven't had time till now to go further, I will try when I have more time.