Plan9/Screencast

19 May 2021 — Igor Böhm

How to create a screencast on Plan9 using wrec…

⑨ lab ≡ 9front p9rn screencast… — `term% @{ramfs ; cd /tmp ; hget https://9lab.org/vid/plan9/9.mp4 > 9.mp4 && treason 9.mp4}`

The above screencast was recorded on 9front Mit Fruchtgeschmack using wrec running on a Lenovo T420s featuring:

The Web: ‘tabbed’ browsing using netsurf and virtual rio screens
Email: acme, Mail, and upas/fs for Email
Music: via the audio player zuke
Chat: via wircrc and virtual rio screens to join the one and only #cat-v IRC channel
Video: watch videos using treason
Remote Desktop: using rd to connect to Windows via RDP
Drawterm: to connect to Plan9 systems from an alien OS
Trivia: running games/catclock

The screencast has been recorded using this command (thanks Dan):

% cat $home/bin/rc/screencast
#!/bin/rc
rfork ne
tm=`{date -i -t}
label screencast
sleep 5
wrec -f 3 /dev/screen >/tmp/screencast.$tm

Converting a screencast to a looping animated gif is accomplished using convert from the ImageMagick family of utilities running on UNIX:

% sshfs darwin.home
% cp /tmp/screencast.2021-06-01T08:14:55+02:00 \
    /n/ssh/Users/igor/9front-p9rn.gif
% vt -bx ssh darwin.home
% convert -delay 20 -loop 0 -resize 850        \
    9front-p9rn.gif  9front-p9rn-loop.gif

To convert the animated gif to a video that can be uploaded to youtube ffmpeg can be used like this:

% ffmpeg -i 9front-p9rn.gif\
    -movflags faststart -pix_fmt yuv420p       \
    -vf 'scale=trunc(iw/2)*2:trunc(ih/2)*2'    \
    9front-p9rn.mp4

And here is what the result looks like on youtube:

#Plan9 #9front