I tried this using Ubuntu (arm64) for the Raspberry but it was kinda slow. So now I´m using standard Raspberry OS (armhf). Make sure to use a good and fast sd card!

1. sudo apt update
2. sudo apt upgrade
3. (optional (for using remote desktop)) sudo apt install xrdp
4. sudo apt install build-essential checkinstall cmake git libmbedtls-dev libasound2-dev libavcodec-dev libavdevice-dev libavfilter-dev libavformat-dev libavutil-dev libcurl4-openssl-dev libfontconfig1-dev libfreetype6-dev libgl1-mesa-dev libjack-jackd2-dev libjansson-dev libluajit-5.1-dev libpulse-dev libqt5x11extras5-dev libspeexdsp-dev libswresample-dev libswscale-dev libudev-dev libv4l-dev libvlc-dev libx11-dev libx11-xcb1 libx11-xcb-dev libxcb-xinput0 libxcb-xinput-dev libxcb-randr0 libxcb-randr0-dev libxcb-xfixes0 libxcb-xfixes0-dev libx264-dev libxcb-shm0-dev libxcb-xinerama0-dev libxcomposite-dev libxinerama-dev pkg-config python3-dev qtbase5-dev libqt5svg5-dev swig qtbase5-private-dev libwayland-dev
5. sudo apt update
6. sudo apt upgrade
7. wget http://ftp.debian.org/debian/pool/non-free/f/fdk-aac/libfdk-aac2_2.0.1-1_armhf.deb
8. wget http://ftp.debian.org/debian/pool/non-free/f/fdk-aac/libfdk-aac-dev_2.0.1-1_armhf.deb
9. sudo dpkg -i libfdk-aac2_2.0.1-1_armhf.deb
10. sudo dpkg -i libfdk-aac-dev_2.0.1-1_armhf.deb
11. sudo git clone –recursive https://github.com/obsproject/obs-studio.git
12. cd obs-studio
13. mkdir build
14. cd build
15. sudo cmake -DUNIX_STRUCTURE=1 -DCMAKE_INSTALL_PREFIX=/usr ..
16. sudo make -j4
17. sudo make install
18. sudo nano /usr/share/applications/com.obsproject.Studio.desktop
19. change Exec=obs to bash -c “MESA_GL_VERSION_OVERRIDE=3.3 obs”
20. MESA_GL_VERSION_OVERRIDE=3.3 obs