Tech insights

Screen mirroring using GNU Emacs from Debian XFCE to LG UJ632T   Note: Don't forget to quit properly (or use wpa_cli p2p_cancel ). Else your computer will continue to scan for peers in the background. Config (require 'tv) (setq wfd-wpa-cli " /usr/sbin/wpa_cli ")   Code https://gitlab.com/atamariya/emacs/-/blob/dev/lisp/tv.el https://gitlab.com/atamariya/hostap/-/blob/tools/wpaspy/wfd.py (RTSP server)   Setup We need to be able to run wpa_cli and nmcli as a normal user. Hence we will add the user and the tools to netdev group.   - Edit /usr/lib/systemd/system/wpa_supplicant.service (as root) ExecStart=/sbin/wpa_supplicant -u -s -O /run/wpa_supplicant -G netdev   - Restart wpa_supplicant (as root). systemctl daemon-reload service wpa_supplicant restart    - Modify user group, file permissions and path. sudo adduser <username> netdev chown -R :netdev /usr/sbin/wpa_cli /var/run/wpa_supplicant/* export PATH=/usr/sbin:$PATH    - Start th...

 Use multi-touch gestures in GNU Emacs.   - Install touchegg https://github.com/JoseExposito/touchegg - Create a copy of touchegg.conf $ mkdir -p ~/.config/touchegg && cp -n /usr/share/touchegg/touchegg.conf ~/.config/touchegg/touchegg.conf   - Add a section for Emacs (pinch to zoom) before closing <touchegg> tag.    <application name="Emacs">     <gesture type="PINCH" fingers="2" direction="IN">       <action type="SEND_KEYS">         <repeat>true</repeat>         <modifiers>Control_L</modifiers>         <keys>x+KP_Subtract</keys>         <decreaseKeys>KP_Add</decreaseKeys>       </action>     </gesture>     <gesture type="PINCH" fingers...

Screen mirroring allows you to display your laptop screen on a TV via Wifi Direct . This is also known as screen casting, Miracast, Wifi Display or Wifi P2P. Usage of Wifi Direct means you don't necessarily need a router or a working network. The data is streamed using RTSP . However, it doesn't use the standard RTSP port. The port information is shared during connection process (usually defaults to 7236 as per Miracast specifications). Also, the RTSP server must support additional Miracast related negotiations. Note: Feature-wise, Second Screen or DIAL (DIscovery And Launch) provides similar experience (primarily for Youtube and Netflix apps). But this (DIAL) requires both the devices to be in the same network. Debian XFCE meets LG 4K TV (UJ632T) The core of this technology in Linux is wpa_supplicant (or its variant - connmand or miracle-wifid). connmand (for WDS ) and miracle-wifid (for MiracleCast ) also manage your network interface. You might also have NetworkManager ...

After a recent upgrade on debian bullseye (Debian 5.10.84-1 (2021-12-08)), I was unable to get a graphical display after resuming from hibernate. Though terminal login worked just fine. Seems like it's a problem with NetworkManager changing hostname. It will change it if the hostname variable is not set in configuration file. Following advice at https://bbs.archlinux.org/viewtopic.php?pid=684936#p684936 , I added following two lines in /etc/NetworkManager/NetworkManager.conf   [keyfile] hostname = <your hostname>        

While people prefer fancy desktops, I prefer the minimal look. I like blank screen to a wallpaper. However, to my surprise, it wasn't an easy option on Debian xfce desktop. I tried a Google search - but that wasn't helpful too. Why should this be so complicated? I must be missing something - I wondered. Turns out, the setting was right under my nose. Select Desktop Settings -> Style: None -> Color: Solid Color. That's it!!!