Lucio Chiappetti
New Member
Since last week google meet (used in our institution for online seminars) no longer offer the possibility of recording, and OBS was mentioned as a possibility. So I had a try on my office desktop (openSUSE Leap 42.3, window manager fvwm 2.6.6). Smooth installation, I choose "optimize for recording" in the wizard, I customized where recordings are stored and their format. However I'd need some more hints to finalize my scenario and solve some problems.
One scenario (mainly for seminars) would be that somebody (the seminar organizer or an attendee) records a seminar so that other people can listen and view to it later in playback. This implies using two sources (a window capture of the browser where the seminar is transmitted, and the audio output capture)
Another scenario (for presentations prepared in advance) may imply a different combination of sources (the audio input capture, i.e. microphone, and either a collection of different window captures, like a browser, a PDF viewer, a terminal or other app for a demo: of the entire screen capture).
For those who are not familiar with fvwm, such window manager allows to have a number of virtual screens (called desktops or pages, there is a difference not relevant here), so a given window can occupy one desktop or be sticky across all desktops.
The entire screen capture works nicely per se (specially if one has to show different sources from many different windows) but has one practical problem. To start recording you have to press the button in OBS open in the current screen, and then switch to the other screens, and at the end one has to go back to the screen with OBS to press end recording. Of course one would not want the two little pieces at beginning and end to be in the final recording. How does one do that ? I see there is a provision for scripts, but see no info in the wiki. Is it e.g. possible to start recording after a delay ?
For the window capture case I found that defining more windows as sources is not particularly helpful (one can move one on top or bottom via OBS without interfering with the recording, but it is difficult to resize the views of the windows so that each one covers exactly all the others). It is more promising to define more scenes, each scene with only one window capture ... and presumably the s ... and use OBS to switch scene. Is this correct ? And shall one include audio capture in all scenes ?
Window capture has however two problems.
One is trivial and taken into account already. Colours are wrong unless one ticks "swap red with blue"
The other one is the occurrence of the error glCopyImageSubData failed, glGetError returned 0x502. At the beginning I was quite puzzled because this started appearing related to a window I had previously successfully captured and used in a test recording. Then I noticed that the error did not occur when I selected a window of a given type (say an xterm terminal or a text editor) and did occur for another window of the same type. So I inspected on the reason. Apparently the window being captured shall be in the same desktop as OBS when the source is added or edited. So one has to make it sticky to the OBS desktop when adding it as a source. After that apparently it can be moved to another desktop (and even iconified although I'm not sure that applies to all windows) and will be recorded.
Is this expected behaviour or is it a bug or feature with either OBS or fvwm ?
One scenario (mainly for seminars) would be that somebody (the seminar organizer or an attendee) records a seminar so that other people can listen and view to it later in playback. This implies using two sources (a window capture of the browser where the seminar is transmitted, and the audio output capture)
Another scenario (for presentations prepared in advance) may imply a different combination of sources (the audio input capture, i.e. microphone, and either a collection of different window captures, like a browser, a PDF viewer, a terminal or other app for a demo: of the entire screen capture).
For those who are not familiar with fvwm, such window manager allows to have a number of virtual screens (called desktops or pages, there is a difference not relevant here), so a given window can occupy one desktop or be sticky across all desktops.
The entire screen capture works nicely per se (specially if one has to show different sources from many different windows) but has one practical problem. To start recording you have to press the button in OBS open in the current screen, and then switch to the other screens, and at the end one has to go back to the screen with OBS to press end recording. Of course one would not want the two little pieces at beginning and end to be in the final recording. How does one do that ? I see there is a provision for scripts, but see no info in the wiki. Is it e.g. possible to start recording after a delay ?
For the window capture case I found that defining more windows as sources is not particularly helpful (one can move one on top or bottom via OBS without interfering with the recording, but it is difficult to resize the views of the windows so that each one covers exactly all the others). It is more promising to define more scenes, each scene with only one window capture ... and presumably the s ... and use OBS to switch scene. Is this correct ? And shall one include audio capture in all scenes ?
Window capture has however two problems.
One is trivial and taken into account already. Colours are wrong unless one ticks "swap red with blue"
The other one is the occurrence of the error glCopyImageSubData failed, glGetError returned 0x502. At the beginning I was quite puzzled because this started appearing related to a window I had previously successfully captured and used in a test recording. Then I noticed that the error did not occur when I selected a window of a given type (say an xterm terminal or a text editor) and did occur for another window of the same type. So I inspected on the reason. Apparently the window being captured shall be in the same desktop as OBS when the source is added or edited. So one has to make it sticky to the OBS desktop when adding it as a source. After that apparently it can be moved to another desktop (and even iconified although I'm not sure that applies to all windows) and will be recorded.
Is this expected behaviour or is it a bug or feature with either OBS or fvwm ?