Ich wurde zum Thema Kraft von den sehr aktiven und sachkundigen Aktiven hinter https://gnulinux.ch/ kontaktiert und interviewt. Es war ein sehr angenehmes und ausführliches Gespräch zur Geschichte, dem Hintergrund und der Entwicklung von Kraft.

Das vollständige Interview ist im Podcast GLN009 erschienen. Wer vorspulen möchte: Es startet etwa bei 1:20h, aber auch die anderen Themen lohnen sich

Three openSUSE Tumbleweed snapshots were released since last Thursday.

Most of the package updates focused on libraries and YaST packages as well as documentation and nmap.

The snapshot from Tuesday, 20210330, updated an enormous amount of YaST translations and minor style adjustments and improvements were made with the yast2-theme 4.3.8 update. Extra validations were added to yast2-storage-ng 4.3.50 when creating a striped volume and when editing the physical volumes. The update to the 4.3.63 version of yast2-network brought about a dozen improvements to include adding support to write bridge and bonding configurations. Abstraction library libyui removed a dependency on Xlib and has a new packaging system in the update to 4.1.2. Network scanner nmap fixed a MySQL library that was not properly parsing responses in version 7.91 and the update of purple-lurch, which does secure multi-client end-to-end encryption, had some memory handling improvements in the 0.7.0 version update.

Topping the list of package updates for snapshot 20210329 was an update of setools 4.4.0 that added a configuration file driven analysis tool and Xfce file manager thunar 4.16.6 removed a dialog box and revamped documentation across components. A memory leak and an integer overflow fix was made in the update of checkpolicy 3.2. File system utility e2fsprogs 1.46.2 fixed warnings when resizing small file systems to a super-large ones. Spell checking library enchant 2.2.15 had some minor build system improvements and requires nuspell 4.1.0 or greater. Other packages that received updates were ffmpeg-4 4.3.2, perl-Net-HTTP 6.21, man-pages 5.11, rubygem-rspec-rails 5.0.1 and more.

The pixel encoding and color space conversion engine babl 0.1.86 had an a change to a profile for creating RGB spaces in snapshot 20210325. Xfce application library exo fixed a keyboard navigation item in its 4.16.1 update. A few Python Package Index updates were also made in the snapshot; a fix was made with LVM root volume inclusion in fstab with the update of python-kiwi 9.23.22 and mailing list management system python-mailman 3.3.4 improved the speed of members lookup via REST Application Programming Interface. Other packages updated in the snapshot were updates to libressl 3.2.5, mpg123 1.26.5 and the transactional-update 3.3.0 package used for MicroOS and Kubic added support for more package managers by bind mounting their directories; the package also linked the RPM database correctly with older zypper versions.

Google Pixel phones support what they call ”Motion Photo” which is essentially a photo with a short video clip attached to it. They are quite nice since they bring the moment alive, especially as the capturing of the video starts a small moment before the shutter button is pressed. For most viewing programs they simply show as static JPEG photos, but there is more to the files.

I’d really love proper Shotwell support for these file formats, so I posted a longish explanation with many of the details in this blog post to a ticket there too. Examples of the newer format are linked there too.

There are actually two different formats, an old one that is already obsolete, and a newer current format. The older ones are those that your Pixel phone recorded as ”MVIMG_[datetime].jpg", and they have the following meta-data:

Xmp.GCamera.MicroVideo                       XmpText     1  1
Xmp.GCamera.MicroVideoVersion                XmpText     1  1
Xmp.GCamera.MicroVideoOffset                 XmpText     7  4022143
Xmp.GCamera.MicroVideoPresentationTimestampUs XmpText     7  1331607

The offset is actually from the end of the file, so one needs to calculate accordingly. But it is exact otherwise, so one simply extract a file with that meta-data information:

#!/bin/bash
#
# Extracts the microvideo from a MVIMG_*.jpg file

# The offset is from the ending of the file, so calculate accordingly
offset=$(exiv2 -p X "$1" | grep MicroVideoOffset | sed 's/.*\"\(.*\)"/\1/')
filesize=$(du --apparent-size --block=1 "$1" | sed 's/^\([0-9]*\).*/\1/')
extractposition=$(expr $filesize - $offset)
echo offset: $offset
echo filesize: $filesize
echo extractposition=$extractposition
dd if="$1" skip=1 bs=$extractposition of="$(basename -s .jpg $1).mp4"

The newer format is recorded in filenames called ”PXL_[datetime].MP.jpg”, and they have a _lot_ of additional metadata:

Xmp.GCamera.MotionPhoto                      XmpText     1  1
Xmp.GCamera.MotionPhotoVersion               XmpText     1  1
Xmp.GCamera.MotionPhotoPresentationTimestampUs XmpText     6  233320
Xmp.xmpNote.HasExtendedXMP                   XmpText    32  E1F7505D2DD64EA6948D2047449F0FFA
Xmp.Container.Directory                      XmpText     0  type="Seq"
Xmp.Container.Directory[1]                   XmpText     0  type="Struct"
Xmp.Container.Directory[1]/Container:Item    XmpText     0  type="Struct"
Xmp.Container.Directory[1]/Container:Item/Item:Mime XmpText    10  image/jpeg
Xmp.Container.Directory[1]/Container:Item/Item:Semantic XmpText     7  Primary
Xmp.Container.Directory[1]/Container:Item/Item:Length XmpText     1  0
Xmp.Container.Directory[1]/Container:Item/Item:Padding XmpText     1  0
Xmp.Container.Directory[2]                   XmpText     0  type="Struct"
Xmp.Container.Directory[2]/Container:Item    XmpText     0  type="Struct"
Xmp.Container.Directory[2]/Container:Item/Item:Mime XmpText     9  video/mp4
Xmp.Container.Directory[2]/Container:Item/Item:Semantic XmpText    11  MotionPhoto
Xmp.Container.Directory[2]/Container:Item/Item:Length XmpText     7  1679555
Xmp.Container.Directory[2]/Container:Item/Item:Padding XmpText     1  0

Sounds like fun and lots of information. However I didn’t see why the “length” in first item is 0 and I didn’t see how to use the latter Length info. But I can use the mp4 headers to extract it:

#!/bin/bash
#
# Extracts the motion part of a MotionPhoto file PXL_*.MP.mp4

extractposition=$(grep --binary --byte-offset --only-matching --text -P "\x00\x00\x00\x18\x66\x74\x79\x70\x6d\x70\x34\x32" $1 | sed 's/^\([0-9]*\).*/\1/')

dd if="$1" skip=1 bs=$extractposition of="$(basename -s .jpg $1).mp4"

UPDATE: I wrote most of this blog post earlier. When now actually getting to publishing it a week later, I see the obvious ie the ”Length” is again simply the offset from the end of the file so one could do the same less brute force approach as for MVIMG. I’ll leave the above as is however for the ❤️ of binary grepping.

^{(cross-posted to my other blog)}

Last week, we celebrated the 20th edition of Hack Week. During this time, we are meant to invest our working hours in any project we want: it can be related to your daily duties, something you want to learn or just a crazy experiment. It is up to you. But the idea is to foster collaboration and innovation. And it is not limited to SUSE; the openSUSE community is welcome to join us.

In this blog post, we would like to share some of the projects the YaST team members were working on, even if they are not related to YaST (and some of them aren’t). We encourage you to join the discussion if you are interested in any of them.

YaST Rake Tasks: Run GitHub Actions Locally

Let’s start presenting something that is actually related to YaST. Ladislav Slezak brought some cool stuff to Yast::Rake, a package that provides YaST developers with useful helpers for our daily tasks like running test suites, submitting new package versions and so on.

Now, containers are first class citizens for Yast::Rake, so it is possible to run YaST client directly on containers and, even better, run GitHub actions locally. If you are interested, you should readh Ladislav’s announcement on the mailing list.

Type Check YaST with Sorbet

Martin Vidner has been working for some time to bring type checking to YaST using Sorbet, a gradual type checker for Ruby. YaST is a rather big and old project, and given the dynamic nature of Ruby, we routinely get bug reports caused by typos, wrong method names, and so on.

At this point, we can check a big part of yast2-ruby-bindings.rpm and a small portion of yast2.rpm, which is a significant step forward. But if you want to know more about this promising project, do not hesitate to have a look at the project’s page.

QDirStat: Finding Files that are Shadowed by a Mount

QDirStat is a pretty neat application that helps you to know how your disk space is used, so you can keep your file system clean and tidy. Stefan Hundhammer, author and maintainer of QDirStat, has done extensive research to find files that are shadowed by a mount. The problem with those files is that they will occupy disk space, although they are not accessible.

As a result, Stefan has written a detailed document about that matter, including a nice script to help you in your quest for shadowed files.

gfxboot2: a graphical interface to bootloaders

Steffen Winterfeldt is one of our experts when it comes to system booting (and stack-based languages :wink:). During this Hack Week, he decided to work in gfxboot2, a rework of the original gfxboot that he maintains but written in C. In case you do not know, gfxboot is the software behind the graphical menu that you get when you boot an openSUSE installation medium.

If you are interested, read the project’s README because it contains useful information and a cat picture. :smiley:

UCMT: Unified Config Management Tool

Josef Reidinger has been exploring an interesting concept: the Unified Config Management Tool. This tool allows you to configure your local system and export the configuration to multiple machines. It is a pretty convenient way to go from local to 1:N management.

Wait a minute, it sounds like another configuration management tool, isn’t it? Well, not really. UCMT sits on top of those tools, and it is able to write the configuration in a way that can be used by Salt, Ansible, and so on. Moreover, the plan is to provide additional features like a good-looking user interface and a plugins system.

Do you want to know more? Then, check the project’s repository because it contains many ideas, use cases and even a screencast. You know, a picture is worth a thousand words.

Tracking Horses

Perhaps this is the most original project. Michal Filka started to work on a low-power GPS tracker for animals, although he targets horses at this point. He has identified several problems with the current solutions, so he decided to work on an alternative.

The project is still in the research phase, but it is worth reading his notes. Initially, he thought about using RFID, but lately, he decided to go for an Arduino-based solution adding a GPS or GPRS chip. Even an Android application is on his roadmap!

Even if most of us do not own any horse :smiley:, we cannot wait to see how this project evolves in the future.

Playing with WebAssembly

Finally, the rest of the team (Áncor González, David Díaz, Imobach González, Jose Iván López and Knut Andersen), decided to spent the Hack Week playing around with WebAssembly, the Rust programming language and JavaScript.

The project’s main goal was to see whether the WebAssembly’s promise of using the same compiled code in multiple environments was true. For that matter, they decided to write a simplified data model representing the network configuration, compile it to WebAssembly and try to use it from both environments.

They learned that things are not that straightforward, and you need to keep separate bindings for each platform. So, in the end, it might be better to use JavaScript bindings for the web and FFI based ones for the local system.

By the way, they took the opportunity to play with Glimmer, an interesting DSL framework for writing GUI applications in Ruby.

Closing Words

We are sure that this Hack Week was rather challenging for the organizers, as they needed to work-around the limitations imposed by the COVID-19 mess. But we think they did a great job! We had a lot of fun meeting our colleagues in Work Adventure, we enjoyed the social hours, learned a lot with the Rust Bootcamp and we managed to share our projects and collaborate with each other.

So thanks a lot to everyone involved!