Ubuntu screen recorder with audio- Obs-Studio

Ubuntu 20 have inbuilt recorder which we can be triggered by alt+ctrl+shift+ r

But it does not record the voice to overcome the limitation I am exploring “OBS Studio” its installation steps are given at obsproject.com which I have used.

Step 1) To check if “OpenGL” is available or not as OBS Studio needs openGL 3.3 or later on Linux

ashu@dev:~$ glxinfo | grep "OpenGL"
Command 'glxinfo' not found, but can be installed with:
sudo apt install mesa-utils

As above output says, it is not available and I need to install.

ashu@dev:~$ sudo apt install mesa-utils
[sudo] password for ashu: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  distro-info
Use 'sudo apt autoremove' to remove it.
The following NEW packages will be installed:
  mesa-utils
0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
Need to get 34.2 kB of archives.
After this operation, 150 kB of additional disk space will be used.
Get:1 http://in.archive.ubuntu.com/ubuntu focal/universe amd64 mesa-utils amd64 8.4.0-1build1 [34.2 kB]
Fetched 34.2 kB in 0s (183 kB/s)      
Selecting previously unselected package mesa-utils.
(Reading database ... 200371 files and directories currently installed.)
Preparing to unpack .../mesa-utils_8.4.0-1build1_amd64.deb ...
Unpacking mesa-utils (8.4.0-1build1) ...
Setting up mesa-utils (8.4.0-1build1) ...
Processing triggers for man-db (2.9.1-1) ..

Step 2) It needs FFmpeg

ashu@dev:~$  sudo apt install ffmpeg
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  distro-info
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
  libavdevice58 libavresample4 libdc1394-22 libopenal-data libopenal1 libsdl2-2.0-0 libsndio7.0
Suggested packages:
  ffmpeg-doc libportaudio2 sndiod
The following NEW packages will be installed:
  ffmpeg libavdevice58 libavresample4 libdc1394-22 libopenal-data libopenal1 libsdl2-2.0-0 libsndio7.0
0 upgraded, 8 newly installed, 0 to remove and 3 not upgraded.
Need to get 2,746 kB of archives.
After this operation, 5,480 kB of additional disk space will be used.
Do you want to continue? [Y/n] Y
... 

Step 3) To install virtual camera (it is optional but we should use it in case we want recorded video be recognised by other platform.

ashu@dev:~$ sudo apt install v4l2loopback-dkms
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  distro-info
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
  dctrl-tools dkms
Suggested packages:
  debtags menu v4l2loopback-utils
The following NEW packages will be installed:
  dctrl-tools dkms v4l2loopback-dkms
0 upgraded, 3 newly installed, 0 to remove and 3 not upgraded.
Need to get 156 kB of archives.
After this operation, 708 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
....

Step 4) Final installation of OBS Studio by executing following

1) sudo add-apt-repository ppa:obsproject/obs-studio
2) sudo apt update
3) sudo apt install obs-studio

first two are the standard steps to add a new repo and update the repo. for third sharing the staring and final output.

ashu@dev:~$ sudo apt install obs-studio
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following package was automatically installed and is no longer required:
  distro-info
Use 'sudo apt autoremove' to remove it.
The following additional packages will be installed:
  libdouble-conversion3 libfdk-aac1 libluajit-5.1-2 libluajit-5.1-common libmbedcrypto3 libmbedtls12 libmbedx509-0 libpcre2-16-0
  libqt5core5a libqt5dbus5 libqt5gui5 libqt5network5 libqt5qml5 libqt5quick5 libqt5svg5 libqt5waylandclient5 libqt5waylandcompositor5
  libqt5widgets5 libqt5xml5 libxcb-xinerama0 libxcb-xinput0 qt5-gtk-platformtheme qttranslations5-l10n qtwayland5
Suggested packages:
  qt5-image-formats-plugins qt5-qmltooling-plugins
The following NEW packages will be installed:
  libdouble-conversion3 libfdk-aac1 libluajit-5.1-2 libluajit-5.1-common libmbedcrypto3 libmbedtls12 libmbedx509-0 libpcre2-16-0
  libqt5core5a libqt5dbus5 libqt5gui5 libqt5network5 libqt5qml5 libqt5quick5 libqt5svg5 libqt5waylandclient5 libqt5waylandcompositor5
  libqt5widgets5 libqt5xml5 libxcb-xinerama0 libxcb-xinput0 obs-studio qt5-gtk-platformtheme qttranslations5-l10n qtwayland5
0 upgraded, 25 newly installed, 0 to remove and 3 not upgraded.
Need to get 81.5 MB of archives.
After this operation, 294 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://in.archive.ubuntu.com/ubuntu focal/universe amd64 libdouble-conversion3 amd64 3.1.5-4ubuntu1 [37.9 kB]
.
.
.
Setting up obs-studio (27.0.0-0obsproject1~focal) ...
Processing triggers for mime-support (3.64ubuntu1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu1) ...
Processing triggers for libc-bin (2.31-0ubuntu9.2) ...
Processing triggers for desktop-file-utils (0.24-1ubuntu3) ...
ashu@dev:~$ 

And after this I was able to use OBS Studio and record screen with audio. Check it out.