The FFmpeg suite of multimedia tools is a very powerful toolkit, but sometimes its default behavior just plain surprises me. While I am totally impressed by its capability to stabilize videos taken by my mobile phone, it took me some time to realize that this processing step lost all the metadata. Of course, I did not expect this, and it is trivial to fix the script, but first you need to be aware that the problem even exists.

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My main desktop machine is an AMD Ryzen-2400G on an ASUS PRIME B350M-A motherboard. It came with secure boot disabled and as the first action I installed Debian on it. Back in early 2019, Debian 10 (i.e. Buster) was stable and based on an 4.19 kernel. I knew that the integrated Radeon Vega GPU of this SoC required a more recent kernel, so I used Debian testing (to become Bullseye) right from the beginning. It took me a bit of fiddling until two monitors worked correctly, but after that it became my main machine.

I did read about enabling secure boot back then, but it seemed the implementation for GNU/Linux systems had not been defined properly, and so I left it disabled. Now that I understand the process better, I want to use that additional level of security against unwanted software on my main desktop. This blog post will explain not only the basics but also follow through to the nitty-gritty of key handling. This will be in the context of Debian that I run on my machine, but we will also compare this to an Ubuntu laptop to get an idea on how the distributions differ in handling of this topic

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This blog post describes the changes to my blogging system which have happened in the last few weeks. Note that most of these were not externally visible as I have a manual "nikola deploy" strategy instead of deploying everything in a CI/CD pipeline. And so while the externally visible blog did not change, I worked on its substance internally at the same time as composing new posts.

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Of course it is easy to include a diagram with a post, but the standard procedure to create/edit the diagram with an external GUI tool does not resonate with me. Even back in my diploma thesis I fell in love with Donald Knuth's MetaPost system to describe diagrams in a declarative way and let the tool do the drawing.

For some LaTeX Beamer presentations I used ditaa in the meantime but inside a make flow that took care of the dependencies. The diagrams and the presentation were strictly separated. For the blog posts I did not yet have a good solution, until I switched to blogging in orgmode. Compared to ReST and Asciidoc posts, Emacs orgmode provides a much richer ecosystem with lots of hooks into other systems by means of the org-babel system.

So by switching the post source format, blogging in orgmode should actually hook into e.g. Graphviz out of the box. And indeed with a little fine tuning, this is an amazingly elegant way to include visualizations in the posts.

As org-mode (through exporting to LaTex Beamer) has also become the source format of my presentations, this new freedom easily extends into presentations and even regular PDF documents by exporting to LaTeX only. So the means shown here to produce diagrams for the blog are also usable when you want to generate Beamer presentations or LaTeX documents. As we will see, the choice of output formats is linked to the targeted use-case.

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