Use internal sound card speaker and USB MIC as default

Question

Problem

I'm using UV4L for audio/video streaming.

I'm using 3.5mm speaker, and usb microphone

UV4L uses default audio/video device for streaming, but only audio work.

USB MIC doesn't work.

But arecord test.wav works.

I changed .asoundrc more than 1 million times according to lots of answer on Stack Exchange and raspberry pi forum, but it doesn't work.

Settings

I'm using Stretch raspbian OS and I did sudo rpi-update.

These are my settings.

cat /usr/share/alsa/alsa.conf

....
# show extended name hints
defaults.namehint.extended on
#
defaults.ctl.card 0
defaults.pcm.card 0
defaults.pcm.device 0
....  

and

cat ~/.asoundrc
    pcm.!default {
    type asym
    playback.pcm "hw:0,0"
    capture.pcm "hw:1,0"
}    

and

arecord -l

**** List of CAPTURE Hardware Devices ****
card 1: Device [USB PnP Sound Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0    

and

    arecord -L
null
    Discard all samples (playback) or generate zero samples (capture)
sysdefault:CARD=Device
    USB PnP Sound Device, USB Audio
    Default Audio Device
front:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    Front speakers
surround21:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    4.0 Surround output to Front and Rear speakers
surround41:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio
    Direct sample mixing device
dsnoop:CARD=Device,DEV=0
    USB PnP Sound Device, USB Audio  

and

aplay -l

**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0  

and

aplay -L

null
    Discard all samples (playback) or generate zero samples (capture)
sysdefault:CARD=ALSA
    bcm2835 ALSA, bcm2835 ALSA
    Default Audio Device
dmix:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct sample mixing device
dmix:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct sample mixing device
dsnoop:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct sample snooping device
dsnoop:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct sample snooping device
hw:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct hardware device without any conversions
hw:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct hardware device without any conversions
plughw:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Hardware device with all software conversions
plughw:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Hardware device with all software conversions

Please save my life.

Answer 1

In UV4L there is an option to set the recording device from a list:

–webrtc-recdevice-index arg (=0) index, starting from 0, of the audio recording device to use in the sequence given by the command ‘arecord --list-pcms’

Try each one in the list to see if one is supported.

Answer 2

Edit or create /etc/asound.conf and insert:

pcm.!default {
   type asym
   playback.pcm "plug:hw:0"
   capture.pcm "plug:dsnoop:1"
}

Reboot and the USB microphone should be used in UV4L. At least it worked for me.

Source and further details: Chapter "Audio configuration" at https://www.linux-projects.org/uv4l/installation/