location: androidHdmiGrabber

Institute of Mathematics - PublicMathWiki:

Revision 7 as of 2021-05-17 22:04:58

Clear message

Android: Screen sharing via HDMI

Solution:

  • Share the tablet screen to a Notebook via HDMI.
  • The Notebook uses the shared screen
    • a) like a 'webcam' or
    • b) shows the shared screen and reshare the window.

Hardware

  1. Android Tablet with USB-C connector (Samsung Galaxy S4, S6).
  2. USB-C / HDMI Adapter (plugged into the tablet)
  3. HDMI cable (between 2 and 4)
  4. HDMI capture stick (plugged into the notebook). If the USB port of the HDMI capture stick is to big, use an USB extension.

Use with BBB in a Y27 seminar room

Part 1: Setup BBB

  • Power on the Seminar room laptop.
  • Open the browser.
  • Login to MY > start a BBB stream (or use MS-Teams, Zoom).

  • Share the notebook screen in BBB.
  • Students in the room: switch on the beamer (small black box, takes 2 minutes to power on).

Part 2: Share tablet screen

  • Connect the tablet with HDMI Capture stick to the notebook (see hardware above).
  • Samsung: do not use Samsung DeX .. the tablet will act as a notebook, not as a tablet (in this scenario more disadvantage than advantage).

  • Start @guvcview@ (webcam icon on the left panel)
    • Select the right video source:
      • On tab video controls select device: USB Video: USB Video.

      • There are probably two (same name), check both.
      • A popup appears: Launch new process or restart? >> restart.

  • Frame Rate: doesn't matter
  • Resolution: 1920x 1080
  • Camera output: MJPG - Motion JPEG

Conclusion:

  • The notebook webcam can still show the speaker.
  • A window (=guvcview) is the tablet screen.
  • The quality should be fine for streaming as well as beamer presentation (both at the same time).
  • The seminar room microphones are used as regular.