Tag Archives: video

Audio/video sync + latency test file

Here is an 60 fps audio/video test file with a 440 Hz beep every 3s to test latency in OBS.

Direct download here.

 

Continue reading Audio/video sync + latency test file

Live video projection over 30 meter

Here is a working hardware combination after several failed attempts – jerky moves, black screen, lost signal, color shifts.

Nikon Z6 – switch video toggle @back of camera for clean HDMI output, set video menu to 60 frames (to avoid display lag), setting c3 standby on. 1800€ incl FTZ.

Sirui VH-10X Fluid, 100€ used.

subtel external power supply for Z6 (only this one allows closing of battery compartment). 56€.

Rode VideoMicro Compact. 88€.

Elgato Cam Link 4K with short USB C connector (to avoid shear stress). 122€.

Macbook Pro with USB-C Digital-AV-Multiport-Adapter (other display port and hdmi did not show up as external display in OBS). adapter 72€.

PW-HT225PIR HDMI Extender with power adapter (USB power alone not sufficient, HDMI amplifier failes consistently). 30€.

30m Cat6 cable. 30€.

Short throw Optoma UHD42 4K Beamer – UHD. 1200€

The best videoconferencing system (even running on a Synology box)

There are many $$$ systems. But there are also super nice systems like Big Blue Button, Apache Open Meeting and Jitsi that are working equally well if you stick to Chrome or Firefox.

I recommend Spreed WebRTC audio/video call and conferencing server. Just run

docker pull spreed/webrtc
docker run --rm --name my-spreed-webrtc -p 8080:8080 -p 8443:8443 \
-v `pwd`:/srv/extra -i -t spreed/webrtc

and you are done. The only issue  – how to route your local IP to the docker container?

sudo route -n add -net 0.0.0.0/16  146.x.x.x
sudo route -n delete 0.0.0.0/16  146.x.x.x

In the meantime, I managed to get it also on the Synology DS418play but only with a manual installation using the DS216+ ii docker binary according to some helpful comments on the synology forum.

Firefox 66 runs  microphone, webcam and screen sharing without any problem, Chrome 73 needs a plugin for screen sharing.

 

 

Giants in Medicine

The JCI has a nice series of video interviews with Marc Feldmann, Thomas Südhof, John T Potts, Aaron Ciechanover, Bruce Beutler, Jon Oates, Christine Seidman, Stephen O’Rahilly, Bruce Spiegelman, Paul Greencard, Jeffrey Friedman, Eugene Braunwald, Thomas Starzl, Francis Collins, Paul Marks, Joan Wilson, Donald Seldin, Tadataka Tachi Yamada, Llloyd Hollingsworth Smith, Robert Lefkowitz, Joseph Goldstein, Michael Brown, Harold E. Varmus.
The next generation is at the WALS board.

Making the invisible motion visible

Here is a new MIT video software, that constructs first a backbone of an object showing minor movements while then amplifying these movements to a ridiculous extent. Not clear what I try to explain? See a video at SPON. Although the idea behind Continue reading Making the invisible motion visible