Installation
Download and install the software at obsproject.com for the operating system you are using. The installation varies depending on the operating system, but there are instructions on the OBS website
Setup
The following steps only need to be carried out once (when opening for the first time):
1. set up the source
Start the installed OBS software
In the Sources tab, add a new image source by clicking on + and then select either Display Capture or Window Capture. The difference between the two is that Display Capture captures the entire screen, while Window Capture attaches itself to a window and ignores others.
In the window that opens, the respective source must then be selected: for Display Capture the display (if the computer has several monitors), for Window Capture the corresponding programme window (e.g. Firefox). At the end click Ok
In the window you will see a preview of what is being filmed (this can also be enlarged etc.)
Note: If a source is not visible, it is possible that you have hidden it using the eye symbol
2. set up the video format and audio source
Click on the Settings button (bottom right), then on the Output tab
Under Recording → Recording Format, change the output format to flv
At the top under Recording → Recording Path, you can select the folder in which the recordings will end up
In the Audio tab, make sure that the ‘Default’ option is selected under Devices → Desktop Audio (otherwise you will not hear any sound on the recording later)
OK
Note: MacOS
Under MacOS, desktop recording (i.e. recording the sound that the computer is playing) is not possible by default, but can be set up by installing third-party software.
This software called BlackHole (successor to Soundflower) acts as a so-called loopback device - i.e. it allows you to select the audio output of a device like a microphone in other programmes. The installation works as follows:
Download and install Blackhole: see here
Set up a new Mutiaudio device in Audio MIDI Setup: see here
In the audio settings of OBS (Settings > Audio), set the Monitoring Device setting to the multi-output device set up in step 2
Set the Microphone/AUX Audio setting to Built-In Audio
Set the Microphone/AUX-AUDIO 2 setting to BlackHole 16ch
Start the installed OBS software
Use
The recording can now be started and stopped using the Start Recording button. The recording ends up in the folder selected in step 3 above.
It is probably worth trying out beforehand whether this really works. You can then play the flv file with VLC, for example (or with a current web browser such as Firefox or Chrome).
Audio muting
In the audio mixer area of the main window, you can set how loud (or whether) the audio source is recorded (see above). If you intend to repeatedly switch an audio source (e.g. your own microphone) on or off during recording, it is a good idea to set up a push-to-talk hotkey. This will only arm your own microphone for OBS recording when a key is pressed on the keyboard. This setting can be found under Settings > Audio > Hotkeys > Enable Push-to-talk (tick the checkbox) and then click in the empty field under Settings > Hotkeys Mic/Aux > Push-to-talk and select a keyboard key.
In the Sources tab, add a new image source by clicking on + and then select either Display Capture or Window Capture. The difference between the two is that Display Capture captures the entire screen, while Window Capture attaches itself to a window and ignores others.
In the window that opens, the respective source must then be selected: for Display Capture the display (if the computer has several monitors), for Window Capture the corresponding programme window (e.g. Firefox). At the end click Ok
In the window you will see a preview of what is being filmed (this can also be enlarged etc.)
Note: If a source is not visible, it is possible that you have hidden it using the eye symbol