Cameraserver

Code

• Available via git

Start the camera server

1. ssh onto the pi
2. run the server code as root

Start the viewer: on mcclogin

• Log onto the FACET control server with a proper ssh port tunnel and X-window forwarding:
  1. get onto the SLAC network:   ssh smeuren@rhel6-64.slac.stanford.edu -Y
  2. get onto mcclogin:                    ssh smeuren@mcclogin -Y
  3. make sure you have bash:       bash
  4. get a python3 env:                    source /afs/slac/g/lcls/package/anaconda/envs/python3.8env/bin/activate
  5. clone into git if needed:         git clone /afs/slac/g/cd/swe/git/repos/slac/FACET/facet-E320.git/
  6. get to the right folder:            cd facet-E320/tunnelpi/cameraserver
  7. run the script:                             python3 camviewer.py

Start the viewer: on the FACET control server

• Log onto the FACET control server with a proper ssh port tunnel and X-window forwarding:
  1. get onto the SLAC network   ssh smeuren@rhel6-64.slac.stanford.edu -Y
  2. get onto mcclogin                     ssh smeuren@mcclogin -Y
  3. get onto the control server   ssh fphysics@facet-srv01 -Y -R 42000:e320pi:42000
  4. get a python environment     source $PACKAGE_TOP/anaconda/envs/python3.7env/bin/activate
  5. clone into git if needed           git clone ssh:///afs/slac/g/cd/swe/git/repos/slac/FACET/facet-E320.git
  6. go to the right folder               cd facet-E320/tunnelpi/cameraserver/
  7. run the viewer script                python3 camviewer.py

Streaming of color video from standard webcam (Apr 2022)

• Currently used webcam supports a maximum of 5 FPS at 1920x1080 pixel
• Data a read in YUV format from the camera, converted to BGR via OpenCV  (c++ code)
• One core of the Raspberry pi devotes 20% CPU time to the image conversion
• Data can be read directly into a numpy array for display on the client side (3x8-bit BGR)