How to cut a video where you want (beyond keyframes)

With editor like Avidemux you can cut a video only in correspondence with certain specific points (the Keyframes). Otherwise the video is corrupt. But there are applications that allow you to overcome this limit: for example ShotCut.

To use it a simple way is to add the video to the timeline (with “+”), and to set a cut point (with “][“), so splitting the video, and then to remove the undesired part (after selecting it). Then export the resulting video.

update-grub on btrfs bootable partition

Update-grub could not recognized as bootable a btrfs partition.

A workaround to make a btrfs (bootable) partition recognized by update-grub is to create symlinks to /boot and /etc folders, in this simple way:

  • go to the mounted btrfs partition
  • create symlink for boot
    ln -s @/boot boot
  • create symlink for etc
    ln -s @/etc etc
  • do update-grub

Problems with Plasma 6

In KDE Neon the upgrade to Plasma 6 has produced several problems:

  • No working power commands (logout, restart, shutdown): this could be a problem from espanso (a text expander for Wayland). Try to stop it (espanso stop) and, if so, create a logout script.
  • applications as root from menu don’t work: you can use a code like this (it’s an example):
[Desktop Entry]
Comment=Twin-Panel File Manager
GenericName=File Manager
  • reimage service menu (in Dolphin) could not work; to fix it try with this:
 sudo mv /usr/share/kservices5/ServiceMenus/reimage* /usr/share/kio/servicemenus/

Ugly icons in KDE Plasma 6

The simplest way to get the right icons is to choose breeze as main theme, and then go (as root, ui.g. with Krusader in root mode) to usr/share/icons and rename breeze/places to places.orig, and afterwards symlink places from Humanity Classic to breeze.
To get correctly Humanity Classic you have to install (via Synaptic) Adwaita icons, otherwise you could be forced to remove a lot of essential packages. Installing Adwaita will ask you a very small kind of change.

Replacing Autokey in Wayland

Many Linux distros are leaving xorg (x11) for Wayland, as display server protocol. Unfortunately not all the applications are ready for Wayland.

In particular Autokey, a very useful application to expand text and automatize typing operations, is not (yet) compatible with Wayland.

A quite good replacement of Autokey is Espanso. But there are also some limitations:

  • Espanso has big problems in LibreWriter (abbreviations are often expanded with errors). Similar problems there were also with Autokey in LibreWriter, but Autokey was able to provide some workarounds.
  • Espanso, unlike Autokey, can provide a very small range of hotkeys (such as ctrl + alt + d): Espanso can use only hotkeys with ctrl (not with alt or shift) and a few letters. I.g. “x01” means “ctrl + a”. You can find the whole range of possible combinations here.

However, as long as the main typing operations are in LibreWriter, or Kate, you can use that applications possibilities to expand text.

in LibreWriter there are at least two possibilities (to expand an abbreviation):

  • tools – > autocorrect
  • tools -> autotext

In Kate you can use snippets to create something similar to Autokey.

I.g. to create a snippet to wrap selected text with the tag <h1>, you can add this code as snippet code:

${rangeCommand("<h1>%%1</h1>", "title")}

Choose the title as you prefer (obviously without spaces), and a key combination, i.g. ctrl+1.

Don’t forget to add, in the javascript section (the tab scripts) this code

function rangeCommand(command, def) {
    if (view.selectedText().length > 0) {
        return command.replace("%%1", view.selectedText());
    } else {
        return command.replace("%%1", def);

In this way, you will be able to add a title <h1> to your selected text.

missing gtk icons

Using KDE in a new installation you could don’t have all the gtk icons. If so, try with:

sudo apt-get install --reinstall adwaita-icon-theme-full

Install Kubuntu without EFI bootloader

If you have, i.g., another linux distro, such as KDE-Neon, and you want add Kubuntu as secondary SO, without changing your EFI, you do this way:

  • in Kubuntu (usb iso) menu -> try Kubuntu
  • in a terminal (once logged in): ubiquity -b
  • this will open the graphical installation tool letting you install Kubuntu without modifying existing EFI
  • don’t worry for the warnings (“the system could not start”)
  • after rebooting, in KDE-Neon do update-grub

If you get, with update-grub, an error such this:

Warning: os-prober will not be executed to detect other bootable partitions.
Systems on them will not be added to the GRUB boot configuration.

You can solve adding or uncommenting this line in /etc/default/grub