varqox

How to record multiple applications and microphone into one audio file on Linux

Step 0. Terminology

Sinks are for output, sources are for input. To stream source to sink a loopback must be created. More shall you find there.

Step 1. Create output sink that will be recorded

Our output sink will be named recording.

pacmd load-module module-null-sink sink_name=recording sink_properties=device.description=recording

gokart23

Steps

1. Install qemu-user-static (yay -S qemu-user-static).
   • This might need you to install pcre-static and update PGP keys (follow the tips in the comments here).
2. If not already present, install systemd-binfmt, the revamped version of binfmt-support tools
   • Your system has to support transparent Qemu user emulation, but fortunately, that is mostly enabled once the steps here have been followed.
3. Check the status of the systemd-binfmt unit (systemctl status systemd-binfmt) and (re)start if needed (sudo systemctl restart systemd-binfmt)
   • This unit has ARM support by default, but check the current documentation to make install it if needed
4. Mount the root partition of the ARM system into a folder (for e.g., sudo mount /dev/sdb2 arm_mountpoint)
5. Copy the QEMU ARM static binary (/usr/bin/qemu-arm-static on my distro) to the mounted root directory's usr/bin

cbarraco

# If the server has ffmpeg:
## For the server:
ffmpeg -f fbdev -i /dev/fb0 -f avi pipe:1 | nc -l -p 1234
## For the viewer:
nc 127.0.0.1 1234 | ffplay -i pipe:0

# If the server doesn't have ffmpeg:
## For the server:
sudo cat /dev/fb0 | nc -l -p 1234
## For the viewer (replace 1920x1080 with the server's resolution):