Fedora Workstation 39 and beyond

I have not been so active for a while with writing these Fedora Workstation updates and part of the reason was that I felt I was beginning to repeat myself a lot, which I partly felt was a side effect of writing them so often, but with some time now since my last update I felt that time was ripe again. So what are some of the things we have been working on and what are our main targets going forward? This is not a exhaustive list, but hopefully items you find interesting. Apologize for weird sentences and potential spelling mistakes, but it ended up a a long post and when you read your own words over for the Nth time you start going blind to issues :)

PipeWire

PipeWire 1.0 is available! PipeWire keeps the Linux Multimedia revolution rolling[/caption]So lets start with one of your favorite topics, PipeWire. As you probably know PipeWire 1.0 is now out and I feel it is a project we definitely succeeded with, so big kudos to Wim Taymans for leading this effort. I think the fact that we got both the creator of JACK, Paul Davis and the creator of PulseAudio Lennart Poettering to endorse it means our goal of unifying the Linux audio landscape is being met. I include their endorsement comments from the PipeWire 1.0 release announcement here :

“PipeWire represents the next evolution of audio handling for Linux, taking
the best of both pro-audio (JACK) and desktop audio servers (PulseAudio) and
linking them into a single, seamless, powerful new system.”
– Paul Davis, JACK and Ardour author

“PipeWire is a worthy successor to PulseAudio, providing a feature set
closer to how modern audio hardware works, and with a security model
with today’s application concepts in mind. Version 1.0 marks a
major milestone in completing the adoption of PipeWire in the standard
set of Linux subsystems. Congratulations to the team!”
– Lennart Poettering, Pulseaudio and systemd author

So for new readers, PipeWire is a audio and video server we created for Fedora Workstation to replace PulseAudio for consumer audio, JACK for pro-audio and add similar functionality for video to your linux operating system. So instead of having to deal with two different sound server architectures users now just have to deal with one and at the same time they get the same advantages for video handling. Since PipeWire implemented both the PulseAudio API and the JACK API it is a drop in replacement for both of them without needing any changes to the audio applications built for those two sound servers. Wim Taymans alongside the amazing community that has grown around the project has been hard at work maturing PipeWire and adding any missing feature they could find that blocked anyone from moving to it from either PulseAudio and JACK. Wims personal focus recently has been on an IRQ based ALSA driver for PipeWire to be able to provide 100% performance parity with the old JACK server. So while a lot of Pro-audio users felt that PipeWire’s latency was already good enough, this work by Wim shaves of the last few milliseconds to reach the same level of latency as JACK itself had.

In parallel with the work on PipeWire the community and especially Collabora has been hard at work on the new 0.5 release of WirePlumber, the session manager which handles all policy issues for PipeWire. I know people often get a little confused about PipeWire vs WirePlumber, but think of it like this: PipeWire provides you the ability to output audio through a connected speaker, through a bluetooth headset, through an HDMI connection and so on, but it doesn’t provide any ‘smarts’ for how that happens. The smarts are instead provided by WirePlumber which then contains policies to decide where to route your audio or video, either based on user choice or through preset policies making the right choices automatically, like if you disconnect your USB speaker it will move the audio to your internal speaker instead. Anyway, WirePlumber 0.5 will be a major step forward for WirePlumber moving from using lua scripts for configuration to instead using JSON for configuration while retaining lua for scripting. This has many advantages, but I point you to this excellent blog post by Collabora’s Ashok Sidipotu for the details. Ashok got further details about WirePlumber 0.5 that you can find here.

With PipeWire 1.0 out the door I feel we are very close to reaching one of our initial goals with PipeWire, to remove the need for custom pro-audio distributions like Fedora JAM or Ubuntu Studio, and instead just let audio folks be able to use the same great Fedora Workstation as the rest of the world. With 1.0 done Wim plans next to look a bit at things like configuration tools and similar used by pro-audio folks and also dive into the Flatpak portal needs of pro-audio applications more, to ensure that Flatpaks + PipeWire is the future of pro-audio.

On the video handling side its been a little slow going since there applications need to be ported from relying directly on v4l. Jan Grulich has been working with our friends at Mozilla and Google to get PipeWire camera handling support into Firefox and Google Chrome. At the moment it looks like the Firefox support will land first, in fact Jan has set up a COPR that lets you try it out here. For tracking the upstream work in WebRTC to add PipeWire support Jan set up this tracker bug. Getting the web browsers to use PipeWire is important both to enable the advanced video routing capabilities of PipeWire, but it will also provide applications the ability to use libcamera which is a needed for new modern MIPI cameras to work properly under Linux.

Another important application to get PipeWire camera support into is OBS Studio and the great thing is that community member Georges Stavracas is working on getting the PipeWire patches merged into OBS Studio, hopefully in time for their planned release early next year. You can track Georges work in this pull request.

For more information about PipeWire 1.0 I recommend our interview with Wim Taymans in Fedora Magazine and also the interview with Wim on Linux Unplugged podcast.

HDR
HDRHDR, or High Dynamic Range, is another major effort for us. HDR is a technology I think many of you have become familiar with due to it becoming quite common in TVs these days. It basically provides for greatly increased color depth and luminescence on your screen. This is a change that entails a lot of changes through the stack, because when you introduce into an existing ecosystem like the Linux desktop you have to figure out how to combine both new HDR capable applications and content and old non-HDR applications and content. Sebastian Wick, Jonas Ådahl, Oliver Fourdan, Michel Daenzer and more on the team has been working with other members of the ecosystem from Intel, AMD, NVIDIA, Collabora and more to pick and define the standards and protocols needed in this space. A lot of design work was done early in the year so we been quite focused on implementation work across the drivers, Wayland, Mesa, GStreamer, Mutter, GTK+ and more. Some of the more basic scenarios, like running a fullscreen HDR application is close to be ready, while we are still working hard on getting all the needed pieces together for the more complex scenarios like running SDR and HDR windows composited together on your desktop. So getting for instance full screen games to run in HDR mode with Steam should happen shortly, but the windowed support will probably land closer to summer next year.

Wayland remoting
One feature we been also spending a lot of time on is enabling remote logins to a Wayland desktop. You have been able to share your screen under Wayland more or less from day one, but it required your desktop session to be already active. But lets say you wanted to access your Wayland desktop running on a headless system you been out of luck so far and had to rely on the old X session instead. So putting in place all the pieces for this has been quite an undertaking with work having been done on PipeWire, on Wayland portals, gnome remote desktop daemon, libei; the new input emulation library, gdm and more. The pieces needed are finally falling into place and we expect to have everything needed landed in time for GNOME 46. This support is currently done using a private GNOME API, but a vendor less API is being worked on to replace it.

As a sidenote here not directly related to desktop remoting, but libei has also enabled us to bring xtest support to XWayland which was important for various applications including Valves gamescope.

NVIDIA drivers
One area we keep investing in is improving the state of NVIDIA support on Linux. This comes both in the form of being the main company backing the continued development of the Nouveau graphics driver. So the challenge with Nouveau is that for the longest while it offered next to no hardware acceleration for 3D graphics. The reason for this was that the firmware that NVIDIA provided for Nouveau to use didn’t expose that functionality and since recent generations of NVIDIA cards only works with firmware signed by NVIDIA this left us stuck. So Nouveau was a good tool for doing an initial install of a system, but if you where doing any kind of serious 3D acceleration, including playing games, then you would need to install the NVIDIA binary driver. So in the last year that landscape around that has changed drastically, with the release of the new out-of-tree open source driver from NVIDIA. Alongside that driver a new firmware has also been made available , one that do provide full support for hardware acceleration.
Let me quickly inject a quick explanation of out-of-tree versus in-tree drivers here. An in-tree driver is basically a kernel driver for a piece of hardware that has been merged into the official Linux kernel from Linus Torvalds and is thus being maintained as part of the official Linux kernel releases. This ensures that the driver integrates well with the rest of the Linux kernel and that it gets updated in sync with the rest of the Linux kernel. So Nouveau is an in-tree kernel driver which also integrates with the rest of the open source graphics stack, like Mesa. The new NVIDIA open source driver is an out-of-tree driver which ships as a separate source code release on its own schedule, but of course NVIDIA works to keeps it working with the upstream kernel releases (which is a lot of work of course and thus considered a major downside to being an out of tree driver).

As of the time of writing this blog post NVIDIAs out-of-tree kernel driver and firmware is still a work in progress for display usercases, but that is changing with NVIDIA exposing more and more display features in the driver (and the firmware) with each new release they do. But if you saw the original announcement of the new open source driver from NVIDIA and have been wondering why no distribution relies on it yet, this is why. So what does this mean for Nouveau? Well our plan is to keep supporting Nouveau for the foreseeable future because it is an in-tree driver, which is a lot easier to ensure keeps working with each new upstream kernel release.

At the same time the new firmware updates allows Nouveau to eventually offer performance levels competitive with the official out-of-tree driver, kind of how the open source AMD driver with MESA offers comparable performance to AMD binary GPU driver userspace. So Nouvea maintainer Ben Skeggs spent the last year working hard on refactoring Nouveau to work with the new firmware and we now have a new release of Nouveau out showing the fruits of that labor, enabling support for NVIDIAs latest chipset. Over time we will have it cover more chipset and expand Vulkan and OpenGL (using Zink) support to be a full fledged accelerated graphics driver.
So some news here, Ben after having worked tirelessly on keeping Nouveau afloat for so many years decided he needed a change of pace and thus decided to leave software development behind for the time being. A big thank you to Ben from all us at Red Hat and Fedora ! The good news is that Danilo Krummrich will take over as the development lead, with Lyude Paul taking on working on the Display side specifically of the driver. We also expect to have other members of the team chipping in too. They will pick up Bens work and continue working with NVIDIA and the community on a bright future for Nouveau.

So as I mentioned though the new open source driver from NVIDIA is still being matured for the display usercase and until it works fully as a display driver neither will Nouveau be able to be a full alternative since they share the same firmware. So people will need to rely on the binary NVIDIA Driver for some time still. One thing we are looking at there and discussing is if there are ways for us to improve the experience of using that binary driver with Secure Boot enabled. Atm that requires quite a bit of manual fiddling with tools like mokutils, but we have some ideas on how to streamline that a bit, but it is a hard nut to solve due to a combination of policy issues, legal issues, security issues and hardware/UEFI bugs so I am making no promises at this point, just a promise that it is something we are looking at.

Accessibility
Accessibility is an important feature for us in Fedora Workstation and thus we hired Lukáš Tyrychtr to focus on the issue. Lukáš has been working through across the stack fixing issues blocking proper accessibility support in Fedora Workstation and also participated in various accessibility related events. There is still a lot to do there so I was very happy to hear recently that the GNOME Foundation got a million Euro sponsorship from the Sovereign Tech Fund to improve various things across the stack, especially improving accessibility. So the combination of Lukáš continued efforts and that new investment should make for a much improved accessibility experience in GNOME and in Fedora Workstation going forward.

GNOME Software
Another area that we keep investing in is improving GNOME Software, with Milan Crha working continuously on bugfixing and performance improvements. GNOME Software is actually a fairly complex piece of software as it has to be able to handle the installation and updating of RPMS, OSTree system images, Flatpaks, fonts and firmware for us in addition to the formats it handles for other distributions. For some time it felt was GNOME Software was struggling with the load of all those different formats and usercases and was becoming both slow and with a lot of error messages. Milan has been spending a lot of time dealing with those issues one by one and also recently landed some major performance improvements making the GNOME Software experience a lot better. One major change that Milan is working on that I think we will be able to land in Fedora Workstation 40/41 is porting GNOME Software to use DNF5. The main improvement end users will probably notice is that it unifies the caches used for GNOME Software and using dnf on the command line, saving you storage space and also ensuring the two are fully in sync on what RPMS is installed/updated at any given time.

Fedora and Flatpaks

Flatpaks is another key element of our strategy for moving the Linux desktop forward and as part of that we have now enabled all of Flathub to be available if you choose to enable 3rd party repositories when you install Fedora Workstation. This means that the huge universe of applications available on Flathub will be easy to install through GNOME Software alongside the content available in Fedora’s own repositories. That said we have also spent time improving the ease of making Fedora Flatpaks. Owen Taylor jumped in and removed the dependency on a technology called ‘modularity‘ which was initially introduced to Fedora to bring new features around having different types of content and ease keeping containers up to date. Unfortunately it did not work out as intended and instead it became something that everyone just felt made things a lot more complicated, including building Flatpaks from Fedora content. With Owens updates building Flatpaks in Fedora has become a lot simpler and should help energize the effort building Flatpaks in Fedora.

Toolbx
As we continue marching towards a vision for Fedora Workstation to be a highly robust operating we keep evolving Toolbx. Our tool for making running your development environment(s) inside a container and thus allows you to both keep your host OS pristine and up to date, while at the same time using specific toolchains and tools inside the development container. This is a hard requirement for immutable operating systems such as Fedora Silverblue or Universal blue, but it is also useful on operating systems like Fedora Workstation as a way to do development for other platforms, like for instance Red Hat Enterprise Linux.

A major focus for Toolbx since the inception is to get it a stage where it is robust and reliable. So for instance while we prototyped it as a shell script, today it is written in Go to be more maintainable and also to confirm with the rest of the container ecosystem. A recent major step forward for getting that stability there is that starting with Fedora 39, the toolbox image is now a release blocking deliverable. This means it is now built as part of the nightly compose and the whole Toolbx stack (ie. the fedora-toolbox image and the toolbox RPM) is part of the release-blocking test criteria. This shows the level of importance we put on Toolbx as the future of Linux software development and its criticality to Fedora Workstation. Earlier, we built the fedora-toobox image as a somewhat separate and standalone thing, and people interested in Toolbx would try to test and keep the whole thing working, as much as possible, on their own. This was becoming unmanageable because Toolbx integrates with many parts of the distribution from Mutter (ie, the Wayland and X sockets) to Kerberos to RPM (ie., %_netsharedpath in /usr/lib/rpm/macros.d/macros.toolbox) to glibc locale definitions and translations. The list of things that could change elsewhere in Fedora, and end up breaking Toolbx, was growing too large for a small group of Toolbx contributors to keep track of.

We the next release we now also have built-in support for Arch Linux and Ubuntu through the –distro flag in toolbox.git main, thanks again to the community contributors who worked with us on this allowing us to widen the amount of distros supported while keeping with our policy of reliability and dependability. And along the same theme of ensuring Toolbx is a tool developers can rely on we have added lots and lots of new tests. We now have more than 280 tests that run on CentOS Stream 9, all supported Fedoras and Rawhide, and Ubuntu 22.04.

Another feature that Toolbx maintainer Debarshi Ray put a lot of effort into is setting up full RHEL containers in Toolbx on top of Fedora. Today, thanks to Debarshi work you do subscription-manager register --username user@domain.name on the Fedora or RHEL host, and the container is automatically entitled to RHEL content. We are still looking at how we can provide a graphical interface for that process or at least how to polish up the CLI for doing subscription-manager register. If you are interested in this feature, Debarshi provides a full breakdown here.

Other nice to haves added is support for enterprise FreeIPA set-ups, where the user logs into their machine through Kerberos and support for automatically generated shell completions for Bash, fish and Z shell.

Flatpak and Foreman & Katello
For those out there using Foreman to manage your fleet of Linux installs we have some good news. We are in the process of implementing support for Flatpaks in these tools so that you can manage and deploy applications in the Flatpak format using them. This is still a work in progress, but relevant Pulp and Katello commits are Pulp commit Support for Flatpak index endpoints and Katello commits Reporting results of docker v2 repo discovery” and Support Link header in docker v2 repo discovery“.

LVFS
Another effort that Fedora Workstation has brought to the world of Linux and that is very popular arethe LVFS and fwdup formware update repository and tools. Thanks to that effort we are soon going to be passing one hundred million firmware updates on Linux devices soon! These firmware updates has helped resolve countless bugs and much improved security for Linux users.

But we are not slowing down. Richard Hughes worked with industry partners this year to define a Bill of Materials defintion to firmware updates allowing usings to be better informed on what is included in their firmware updates.

We now support over 1400 different devices on the LVFS (covering 78 different protocols!), with over 8000 public firmware versions (image below) from over 150 OEMs and ODMs. We’ve now done over 100,000 static analysis tests on over 2,000,000 EFI binaries in the firmware capsules!

Some examples of recently added hardware:
* AMD dGPUs, Navi3x and above, AVer FONE540, Belkin Thunderbolt 4 Core Hub dock, CE-LINK TB4 Docks,CH347 SPI programmer, EPOS ADAPT 1×5, Fibocom FM101, Foxconn T99W373, SDX12, SDX55 and SDX6X devices, Genesys GL32XX SD readers, GL352350, GL3590, GL3525S and GL3525 USB hubs, Goodix Touch controllers, HP Rata/Remi BLE Mice, Intel USB-4 retimers, Jabra Evolve 65e/t and SE, Evolve2, Speak2 and Link devices, Logitech Huddle, Rally System and Tap devices, Luxshare Quad USB4 Dock, MediaTek DP AUX Scalers, Microsoft USB-C Travel Hub, More Logitech Unifying receivers, More PixartRF HPAC devices, More Synaptics Prometheus fingerprint readers, Nordic HID devices, nRF52 Desktop Keyboard, PixArt BLE HPAC OTA, Quectel EM160 and RM520, Some Western Digital eMMC devices, Star Labs StarBook Mk VIr2, Synaptics Triton devices, System76 Launch 3, Launch Heavy 3 and Thelio IO 2, TUXEDO InfinityBook Pro 13 v3, VIA VL122, VL817S, VL822T, VL830 and VL832, Wacom Cintiq Pro 27, DTH134 and DTC121, One 13 and One 12 Tablets

InputLeap on Wayland
One really interesting feature that landed for Fedora Workstation 39 was the support for InputLeap. It’s probably not on most peoples radar, but it’s an important feature for system administrators, developers and generally anyone with more than a single computer on their desk.

Historically, InputLeap is a fork of Barrier which itself was a fork of Synergy, it allows to share the same input devices (mouse, keyboard) across different computers (Linux, Windows, MacOS) and to move the pointer between the screens of these computers seamlessly as if they were one.

InputLeap has a client/server architecture with the server running on the main host (the one with the keyboard and mouse connected) and multiple clients, the other machines sitting next to the server machine. That implies two things, the InputLeap daemon on the server must be able to “capture” all the input events to forward them to the remote clients when the pointer reaches the edge of the screen, and the InputLeap client must be able to “replay” those input events on the client host to make it as if the keyboard and mouse were connected directly to the (other) computer. Historically, that relied on X11 mechanisms and neither InputLeap (nor Barrier or even Synergy as a matter of fact) would work on Wayland.

This is one of the use cases that Peter Hutterer had in mind when he started libEI, a low-level library aimed at providing a separate communication channel for input emulation in Wayland compositors and clients (even though libEI is not strictly tied to Wayland). But libEI alone is far from being sufficient to implement InputLeap features, with Wayland we had the opportunity to make things more secure than X11 and take benefit from the XDG portal mechanisms.

On the client side, for replaying input events, it’s similar to remote desktop but we needed to update the existing RemoteDesktop portal to pass the libEI socket. On the server side, it required a brand new portal for input capture . These also required their counterparts in the GNOME portal, for both RemoteDesktop and InputCapture [8], and of course, all that needs to be supported by the Wayland compositor, in the case of GNOME that’s mutter. That alone was a lot of work.

Yet, even with all that in place, that’s just the basic requirements to support a Synergy/Barrier/InputLeap-like feature, the tools in question need to have support for the portal and libEI implemented to benefit from the mechanisms we’ve put in place and for the all feature to work and be usable. So libportal was also updated to support the new portal features and a new “Wayland” backend alongside the X11, Windows and Mac OS backends was contributed to InputLeap.

The merge request in InputLeap was accepted very early, even before the libEI API was completely stabilized and before the rest of the stack was merged, which I believe was a courageous choice from Povilas (who maintains InputLeap) which helped reduce the time to have the feature actually working, considering the number of components and inter-dependencies involved. Of course, there are still features missing in the Wayland backend, like copy/pasting between hosts, but a clipboard interface was fairly recently added to the remote desktop portal and therefore could be used by InputLeap to implement that feature.

Fun fact, Xwayland also grew support for libEI also using the remote desktop portal and wires that to the XTEST extension on X11 that InputLeap’s X11 backend uses, so it might even be possible to use the X11 backend of InputLeap in the client side through Xwayland, but of course it’s better to use the Wayland backend on both the client and server sides.

InputLeap is a great example of collaboration between multiple parties upstream including key contributions from us at Red Hat to implement and contribute a feature that has been requested for years upstream..

Thank you to Olivier Fourdan, Debarshi Ray, Richard Hughes, Sebastian Wick and Jonas Ådahl for their contributions to this blog post.

Update from the world of Fedora Workstation

Let me start by saying that I now also have a Mastodon account, so please follow me on @Cfkschaller@fosstodon.org for news and updates around Fedora Workstation, PipeWire, Wayland, LVFS and Linux in general.

Fedora vs Fedora Workstation
Before I start with the general development update I want to mention something I mentioned quite a few times before and that is the confusion I often find people have about what is Fedora and what is Fedora Workstation.

Fedora Workstation

Fedora is our overall open source project and community working on packaging components and software for the various outputs that the Fedora community delivers. Think of the Fedora community a bit like a big group of people providing well tested and maintained building blocks to be used to build operating systems and applications. As part of that bigger community you have a lot of working groups and special interest groups working to build something with those building blocks and Fedora Workstation is the most popular thing being built from those building blocks. That means that Fedora Workstation isn’t ‘Fedora’ it is something created by the Fedora community alongside a lot of other projects like Fedora Server, Silverblue and Fedora spins like Fedora KDE and Fedora Kinoite. But all them should be considered separate efforts built using a shared set of building blocks.
Putting together an operating system like Fedora Workstation is more than just assembling a list of software components to include though, it is also about setting policies, default configurations, testing and QE and marketing. This means that while Fedora Workstation contains many of the same components of other things like the Fedora KDE Plasma Desktop spin, the XFCE Desktop spin, the Cinnamon spin and so on, they are not the same thing. And that is not just because the feature set of GNOME is different from the feature set of XFCE, it is because each variant is able to set their own policies, their own configurations and do their own testing and QE. Different variants adopted different technologies at different times, for instance Fedora Workstation was an early adopter of new technologies like Wayland and PipeWire. So the reason I keep stressing this point is that I to this day often see comments or feedback about ‘Fedora’, feedback which as someone spending a lot of effort on Fedora Workstation, sometimes makes no sense to me, only to reach out and discover that they where not using Fedora Workstation, but one of the spins. So I do ask people, especially those who are members of the technology press to be more precise in their reviews, about if they are talking about Fedora Workstation or another project that is housed under the Fedora umbrella and not just shorten it all to ‘Fedora’.

Fedora Workstation

Fedora Workstation


Anyway, onwards to updating you on some of the work we are doing in and around Fedora Workstation currently.

High Dynamic Range – HDR

HDR

HDR

A major goal for us at Red Hat is to get proper HDR support into Fedora and RHEL. Sebastian Wick is leading that effort for us and working with partners and contributors across the community and the industry. For those who read my past updates you know I have been talking about this for a while, but it has been slow moving both because it is a very complex issue that needs changes from the kernel graphics drivers up through the desktop shell and into the application GUI toolkits. As Sebastian put it when I spoke with him, HDR forces us (the Linux ecosystem) to take colors seriously for the first time and thus it reveals a lot of shortcomings up through our stack, many which are not even directly HDR related.
Support for High Dynamic Range (HDR) requires compositors to produce framebuffers in specific HDR encodings with framebuffers from different clients. Most clients nowadays are unaware of HDR, Wide Color Gamuts (WCG) and instead produce pixels with RGB encodings which look okay on most displays which approximate sRGB characteristics. Converting different encodings to the common HDR encoding requires clients to communicate their encoding, the compositor to adjust and convert between the different color spaces, and the driver to enable an HDR mode in the display. Converting between the encodings should ideally be done by the scanout engine of the GPU to keep the latency and power benefits of direct scanout. Similarly, applications and toolkits have to understand different encodings and how to convert between them to make use of HDR and WCG features.

Essentially, HDR forces us to handle color correctly and makes color management an integral part of the system.
So in no particular order here are some of the issues we have found and are looking at:

  • Display brightness controls are today limited to a single, internal monitor and setting the brightness level to zero might or might not turn off the screen. The luminance setting might scale linearly or approximate the human brightness perception depending on hardware. Hans de Goede on our team is working on fixing these issues to get as coherent behaviour from different hardware as possible.
  • GStreamers glcolorconvert element doesn’t actually convert colors, which breaks playback of videos on some HDR and WCG encoded videos.
  • There are also some challenges with limitations in the current KMS API. User space cannot select the bit depth of the colors sent to the display, nor whether a YUV format with subsampling is used. Both are driver internal magic which can reduce the quality of the image but might be required to light up displays with the limited bandwidth available. The handling of limited and full range colors is driver defined and an override for badly behaving sinks is only available on Intel and VC4. And offloading the color transformations to the scanout hardware is impossible with the KMS API. Available features, their order and configurability varies a lot between hardware. To avoid any discrepancy between the offloaded and the software case the entire color pipeline has to be predictable by user space. We’re currently working together with hardware vendors to look at ways forward here.
  • To handle the communication of the color metadata between clients and compositors Sebastian is working with the wider community to define two work-in-progress wayland protocols. The color representation protocol describes how to go from a tristimulus value to the encoding (this includes YUV to RGB conversions, full vs limited color range, chroma siting) and the color-management protocol for describes the tristimulus values (primaries, whitepoint, OETF, ICC profile, dynamic range).
  • There is also now a repository on FreeDesktop.org’s GitLab instance to document and discuss all things related to colors on Linux. This required a lot of research, thinking and discussing about how everything is supposed to fit together.
  • Compositors have to look up information from EDID and DisplayID for HDR. The data is notoriously unreliable currently so Simon Ser, Pekka Paalanen and Sebastian started a new project called libdisplay-info for parsing and quirking EDID+DisplayID.
  • Mutter is now in charge of ICC profile handling and we’re planning to deprecate the old colord daemon. Work on supporting high bit depth framebuffers and enabling HDR mode is ongoing and should give us an experimental setup for figuring out how to combine different SDR and HDR content.

Headless display and automated test of the GNOME Shell

Jonas Ådahl has been working on getting headless display working correctly under Wayland for a bit and as part of that also been working on using the headless display support to enable automated testing of gnome-shell. The core work to get GNOME Shell to be able to run headless on top of Wayland finished some time ago, but there are still some related tasks that need further work.

  • The most critical is remote login. With some hand holding it works and supports TPM based authentication for single user sessions, but currently lacks a nice way to start it. This item is on the very top of Jonas todo list so hopefully we can cross it off soon.
  • Remote multi user login: This feature is currently in active development and will make it possible to get a gdm login screen via gnome-remote-desktop where one can type ones username and password getting a headless session. The remote multi user login is a collaboration between Jonas Ådahl, Pascal Nowack, the author of the RDP backend in gnome-remote-desktop and Joan Torres from SUSE.
  • Testing: Jonas has also been putting in a lot of work recently to improve automated testing of GNOME Shell on the back of the headless display support. You can read more about that in his recent blog post on the subject.

HID-BPF

Benjamin Tissoires has been working on a set of kernel patches for some time now that implements something called HID-BPF. HID referring to Human Interface Devices (like mice, keyboard, joysticks and so on) and BPF is a kernel and user-space observability scheme for the Linux kernel. If you want to learn more about BPF in general I recommend this Linux Journal article on the subject. This blog post will talk specifically about HID-BPF and not BPF in general. We are expecting this patcheset to either land in 6.2 or it might get delayed to 6.3.
The kernel documentation explains in length and through examples how to use HID-BPF and when. The summary would be that in the HID world, we often have to tweak a single byte on a device to make it work, simply because HW makers only test their device under Windows, and they can provide a “driver” that has the fix in software. So most of the time it comes to changing a few bytes in the report descriptor of the HID device, or on the fly when we receive an event. For years, we have been doing this sort of fixes in the kernel through the normal kernel driver model. But it is a relatively slow way of doing it and we should be able to be more efficient.

The kernel driver model process involves multiple steps and requires the reporter of the issue to test the fix at every step. The reporter has an issue and contacts a kernel developer to fix that device (sometimes, the reporter and the kernel developers are the same person). To be able to submit the fix, it has to be tested, and so compiled in the kernel upstream tree, which means that we require regular users to compile their kernel. This is not an easy feat, but that’s how we do it. Then, the patch is sent to the list and reviewed. This often leads to v2, v3 of the patch requiring the user to recompile a new kernel. Once it’s accepted, we still need to wait for the patch to land in Linus’ tree, and then for the kernel to be taken by distributions. And this is only now that the reporter can drop the custom kernel build. Of course, during that time, the reporter has a choice to make: should I update my distro kernel to get security updates and drop my fix, or should I recompile the kernel to keep everybody up to date, or should I just stick with my kernel version because my fix is way more important?
So how can HID-BPF make this easier?

So instead of the extensive process above. A fix can be written as a BPF program which can be run on any kernel. So instead of asking the reporter to recompile the upstream kernel, a kernel developer can compile the BPF program, and provide both the sources and the binary to the tester. The tester now just has to drop that binary in a given directory to have a userspace component automatically binding this program to the device. When the review process happens, we can easily ask testers to update their BPF program, and they don’t even need to reboot (just unplug/replug the target device). For the developers, we continue doing the review, and we merge the program directly in the source tree. Not even a single #define needs to differ. Then an automated process (yet to be fully determined, but Benjamin has an RFC out there) builds that program into the kernel tree, and we can safely ship that tested program. When the program hits the distribution kernel, the user doesn’t even notice it: given that the kernel already ships that BPF program, the userspace will just not attach itself to the device, meaning that the test user will even benefit from the latest fixes if there were any without any manual intervention. Of course, if the user wants to update the kernel because of a security problem or another bug, the user will get both: the security fix and the HID fix still there.

That single part is probably the most appealing thing about HID-BPF. And of course, this translate very well in the enterprise Linux world: when a customer has an issue on a HID device that can be fixed by HID-BPF, we can provide to that customer the pre-compiled binary to introduce in the filesystem without having to rely on a kernel update.
But there is more: we can now start implementing a HID firewall (so that only fwupd can change the firmware of a HID device), we can also tell people not to invent ad-hoc kernel APIs, but rely on eBPF to expose that functionality (so that if the userspace program is not there, we don’t even expose that capability). And we can be even more creative, like deciding to change how the kernel presents a device to the userspace.

Benjamin speaking a Kernel Recipies


For more details I recommend checking out the talk Benjamin did at the kernel recipes conference.

MIPI Camera
Kate Hsuan and Hans de Goede have been working together trying to get the Linux support for MIPI cameras into shape. MIPI cameras are the next generation of PC cameras and you are going to see more and more laptops shipping with these so it is critical for us to get them working and working well and this work is also done in the context of our close collaboration with Lenovo around the Fedora laptops they offer.
Without working support, Fedora Workstation users who buy a laptop equipped with a MIPI camera will only get a black image. The long term solution for MIPI cameras is a library called libcamera which is a project lead by Laurent Pinchart and Kieran Bingham from IdeasOnBoard and sponsored by Google. For desktop Linux users you probably are not going to have applications interact directly with libcamera though, instead our expectation is that your applications use libcamera through PipeWire and the Flatpak portal. Thanks to the work of the community we now have support for the Intel IPU3 MIPI stack in the kernel and through libcamera, but the Intel IPU6 MIPI stack is the one we expect to see head into laptops in a major way and thus our current effort is focused on bringing support for that in a useful way to Fedora users. Intel has so far provided a combination of binary and limited open source code to support these cameras under Linux, by using GStreamer to provide an emulated V4l2 device. This is not a great long term solution, but it does provide us with at least an intermediate solution until we can get IPU6 working with libcamera. Based on his successful work on IPU3, Hans de Goede has been working on getting the necessary part of the Intel open source driver for IPU6 upstreamed since that is the basic interface to control the IPU6 and image sensor. Kate has been working on packaging all the remaining Intel non-free binary and software releases into RPM packages. The packages will provide the v4l2loopback solution which should work with any software supporting V4l2. These packages were planned to go live soon in RPM fusion nonfree repository.

LVFS – Linux Vendor Firmware Service
Richard Hughes is still making great strides forward with the now ubiques LVFS service. A few months ago we pushed the UEFI dbx update to the LVFS, which has now been downloaded over 4 million times. This pushed the total downloads to a new high of 5 million updates just in the 4 weeks of September, although it’s returned to a more normal growth pattern now.

The LVFS also now supports 1,163 different devices, and is being used by 137 different vendors. Since we started all those years ago we’ve provided at least 74 million updates to end-users although it’s probably even more given that lots of Red Hat customers mirror the entire LVFS for internal use. Not to mention that thanks to Richards collaboration with Google LVFS is now an integral part of the ‘Works with ChromeOS’ program.

On the LVFS we also now show the end-user provided HSI reports for a lot of popular hardware. This is really useful to check how secure the device will likely be before buying new hardware, regardless if the vendor is uploading to the LVFS. We’ve also asked ODMs and OEMs who do actually use the LVFS to use signed reports so we can continue to scale up LVFS. Once that is in place we can continue to scale up, aiming for 10,000 supported devices, and to 100 million downloads.

LVFS analytics

Latest LVFS statistics

PipeWire & OBS Studio

In addition to doing a bunch of bug fixes and smaller improvements around audio in PipeWire, Wim Taymans has spent time recently working on getting the video side of PipeWire in shape. We decided to use OBS Studio as our ‘proof of concept’ application because there was already a decent set of patches from Georges Stavracas and Columbarius that Wim could build upon. Getting the Linux developer community to adopt PipeWire for video will be harder than it was for audio since we can not do a drop in replacement, instead it will require active porting by application developers. Unlike for audio where PipeWire provides a binary compatible implementation of the ALSA, PulesAudio and JACK apis we can not provide a re-implementation of the V4L API that can run transparently and reliably in place of the actual V4L2. That said, Wim has created a tool called pw-v4l2 which tries to redirect the v4l2 calls into PipeWire, so you can use that for some testing, for example by running ‘pw-v4l2 cheese’ on the command line and you will see Cheese appear in the PipeWire patchbay applications Helvum and qpwgraph. As stated though it is not reliable enough to be something we can for instance have GNOME Shell do as a default for all camera handling applications. Instead we will rely on application developers out there to look at the work we did in OBS Studio as a best practice example and then implement camera input through PipeWire using that. This brings with it a lot of advantages though, like transparent support for libcamera alongside v4l2 and easy sharing of the video streams between multiple applications.
One thing to note about this is that at the moment we have two ‘equal’ video backends in PipeWire, V4L2 and libcamera, which means you get offered the same device twice, once from v4l2 and once from libcamera. Obviously this is a little confusing and annoying. Since libcamera is still in heavy development the v4l2 backend is more reliable for now, so Fedora Workstation we will be shipping with the v4l2 backend ‘out of the box’, but allow you to easily install the libcamera backend. As libcamera matures we will switch over to the libcamera backend (and allow you to install the v4l backend if you still need/want it for some reason.)

Helvum running OBS Studio with native PipeWire support and Cheese using the pw-v4l2 re-directer.

Of course the most critical thing to get ported to use PipeWire for camera handling is the web browsers. Luckily thanks to the work of Pengutronix there is a patchset ready to be merged into WebRTC, which is the implementation used by both Chromium/Chrome and Firefox. While I can make no promises we are currently looking to see if it is viable for us to start shipping that patch in the Fedora Firefox package soon.

And finally thanks to the work by Jan Grulich in collaboration with Google engineers PipeWire is now included in the Chromium test build which has allowed Google to enable PipeWire for screen sharing enabled by default. Having PipeWire in the test builds is also going to be critical for getting the camera handling patch merged and enabled.

Flathub, Flatpak and Fedora

As I have spoken about before, we have a clear goal of moving as close as we can to a Flatpak only model for Fedora Workstation. The are a lot of reasons for this like making applications more robust (i.e. the OS doesn’t keep moving fast underneath the application), making updates more reliable (because an application updating its dependencies doesn’t risk conflicting with the needs of other application), making applications more portable in the sense that they will not need to be rebuilt for each variety of operating system, to provide better security since applications can be sandboxed in a container with clear access limitations and to allow us to move to an OS model like we have in Silverblue with an immutable core.
So over the last years we spent a lot of effort alongside other members of the Linux community preparing the ground to allow us to go in this direction, with improvements to GTK+ and Qt for instance to allow them to work better in sandboxes like the one provided by Flatpak.
There has also been strong support and growth around Flathub which now provides a wide range of applications in Flatpak format and being used for most major Linux distributions out there. As part of that we have been working to figure out policies and user interface to allow us to enable Flathub fully in Fedora (currently there is a small allowlisted selection available when you enable 3rd party software). This change didn’t make it into Fedora Workstation 37, but we do hope to have it ready for Fedora Workstation 38. As part of that effort we also hope to take another look at the process for building Flatpaks inside Fedora to reduce the barrier for Fedora developers to do so.

So how do we see things evolving in terms of distribution packaging? Well that is a good question. First of all a huge part of what goes into a distribution is not Flatpak material considering that Flatpaks are squarely aimed at shipping GUI desktop applications. There are a huge list of libraries and tools that are either used to build the distribution itself, like Wayland, GNOME Shell, libinput, PipeWire etc. or tools used by developers on top of the operating system like Python, Perl, Rust tools etc. So these will be needed to be RPM packaged for the distribution regardless. And there will be cases where you still want certain applications to be RPM packaged going forward. For instance many of you hopefully are aware of Container Toolbx, our effort to make pet containers a great tool for developers. What you install into your toolbox, including some GUI applications like many IDEs will still need to be packages as RPMS and installed into each toolbox as they have no support for interacting with a toolbox from the host. Over time we hope that more IDEs will follow in GNOME Builders footsteps and become container aware and thus can be run from the host system as a Flatpak, but apart from Owen Taylors VS Code integration plugin most of them are not yet and thus needs to be installed inside your Toolbx.

As for building Flatpaks in Fedora as opposed to on Flathub, we are working on improving the developer experience around that. There are many good reasons why one might want to maintain a Fedora Flatpak, things like liking the Fedora content and security policies or just being more familiar with using the tested and vetted Fedora packages. Of course there are good reasons why developers might prefer maintaining applications on Flathub too, we are fine with either, but we want to make sure that whatever path you choose we have a great developer and package maintainer experience for you.

Multi-Stream Transport

Multi-monitor setups have become more and more common and popular so one effort we spent time on for the last few years is Lyude Paul working to clean up the MST support in the kernel. MST is a specification for DisplayPort that allows multiple monitors to be driven from a single DisplayPort port by multiplexing several video streams into a single stream and sending it to a branch device, which demultiplexes the signal into the original streams. DisplayPort MST will usually take the form of a single USB-C or DisplayPort connection. More recently, we’ve also seen higher resolution displays – and complicated technologies like DSC (Display Stream Compression) which need proper driver support in order to function.

Making setups like docks work is no easy task. In the Linux kernel, we have a set of shared code that any video driver can use in order to much more easily implement support for features like DisplayPort MST. We’ve put quite a lot of work into making this code both viable for any driver to use, but also to build new functionality on top of for features such as DSC. Our hope is that with this we can both encourage the growth of support for functionality like MST, and support of further features like DSC from vendors through this work. Since this code is shared, this can also come with the benefit that any new functionality implemented through this path is far easier to add to other drivers.
Lyude has mostly finished this work now and recently have been focusing on fixing some regressions that accidentally came upstream in amdgpu. The main stuff she was working on beforehand was a lot of code cleanup, particularly removing a bunch of the legacy MST code. For context: with kernel modesetting we have legacy modesetting, and atomic modesetting. Atomic modesetting is what’s used for modern drivers, and it’s a great deal simpler to work with than legacy modesetting. Most of the MST helpers were written before atomic was a thing, and as a result there was a pretty big mess of code that both didn’t really need to be there – and actively made it a lot more difficult to implement new functionality and figure out whether bug fixes that were being submitted to Lyude were even correct or not. Now that we’ve cleaned this up though, the MST helpers make heavy use of atomic and this has definitely simplified the code quite a bit.

Getting rid of the need for the usecase Linux distribution

There was an article on Open for Everyone today about Nobara, a Fedora-based distribution optimized for gaming. So I have no beef with Tomas Crider or any other creator/maintainer of a distribution targeting a specific use case. In fact they are usually trying to solve or work around real problems and make things easier for people. That said I have for years felt that the need for these things is a failing in itself and it has been a goal for me in the context of Fedora Workstation to figure out what we can do to remove the need for ‘usecase distros’. So I thought it would be of interest if I talk a bit about how I been viewing these things and the concrete efforts we taken to reduce the need for usecase oriented distributions. It is worth noting that the usecase distributions have of course proven useful for this too, in the sense that they to some degree also function as a very detailed ‘bug report’ for why the general case OS is not enough.
Before I start, you might say, but isn’t Fedora Workstation as usecase OS too? You often talk about having a developer focus? Yes, developers are something we care deeply about, but for instance that doesn’t mean we pre-install 50 IDEs in Fedora Workstation. Fedora Workstation should be a great general purpose OS out of the box and then we should have tools like GNOME Software and Toolbx available to let you quickly and easily tweak it into your ideal development system. But at the same time by being a general purpose OS at heart, it should be equally easy to install Steam and Lutris to start gaming or install Carla and Ardour to start doing audio production. Or install OBS Studio to do video streaming.

Looking back over the years one of the first conclusions I drew from looking at all the usecase distributions out there was that they often where mostly the standard distro, but with a carefully procured list of pre-installed software, for instance the old Fedora game spin was exactly that, a copy of Fedora with a lot of games pre-installed. So why was this valuable to people? For those of us who have been around for a while we remember that the average linux ‘app store’ was a very basic GUI which listed available software by name (usually quite cryptic names) and at best with a small icon. There was almost no other metadata available and search functionality was limited at best. So finding software was not simple, at it was usually more of a ‘search the internet and if you find something interesting see if its packaged for your distro’. So the usecase distros who focused on having procured pre-installed software, be that games, or pro-audio software or graphics tools ot whatever was their focus was basically responding to the fact that finding software was non-trivial and a lot of people maybe missed out on software that could be useful to them since it they simply never learned about its existence.
So when we kicked of the creation of GNOME Software one of the big focuses early on was to create a system for providing good metadata and displaying that metadata in a useful manner. So as an end user the most obvious change was of course the more rich UI of GNOME Software, but maybe just as important was the creation of AppStream, which was a specification for how applications to ship with metadata to allow GNOME Software and others to display much more in-depth information about the application and provide screenshots and so on.

So I do believe that between working on a better ‘App Store’ story for linux between the work on GNOME Software as the actual UI, but also by working with many stakeholders in the Linux ecosystem to define metadata standards like AppStream we made software a lot more discoverable on Linux and thus reduced the need for pre-loading significantly. This work also provided an important baseline for things like Flathub to thrive, as it then had a clear way to provide metadata about the applications it hosts.
We do continue to polish that user experience on an ongoing basis, but I do feel we reduced the need to pre-load a ton of software very significantly already with this.

Of course another aspect of this is application availability, which is why we worked to ensure things like Steam is available in GNOME Software on Fedora Workstation, and which we have now expanded on by starting to include more and more software listings from Flathub. These things makes it easy for our users to find the software they want, but at the same time we are still staying true to our mission of only shipping free software by default in Fedora.

The second major reason for usecase distributions have been that the generic version of the OS didn’t really have the right settings or setup to handle an important usecase. I think pro-audio is the best example of this where usecase distros like Fedora Jam or Ubuntu Studio popped up. The pre-install a lot of relevant software was definitely part of their DNA too, but there was also other issues involved, like the need for a special audio setup with JACK and often also kernel real-time patches applied. When we decided to include Pro-audio support in PipeWire resolving these issues was a big part of it. I strongly believe that we should be able to provide a simple and good out-of-the box experience for musicians and audio engineers on Linux without needing the OS to be specifically configured for the task. The strong and positive response we gotten from the Pro-audio community for PipeWire I believe points to that we are moving in the right direction there. Not claiming things are 100% yet, but we feel very confident that we will get there with PipeWire and make the Pro-Audio folks full fledged members of the Fedora WS community. Interestingly we also spent quite a bit of time trying to ensure the pro-audio tools in Fedora has proper AppStream metadata so that they would appear in GNOME Software as part of this. One area there where we are still looking at is the real time kernel stuff, our current take is that we do believe the remaining unmerged patches are not strictly needed anymore, as most of the important stuff has already been merged, but we are monitoring it as we keep developing and benchmarking PipeWire for the Pro-Audio usecase.

Another reason that I often saw that drove the creation of a usecase distribution is special hardware support, and not necessarily that special hardware, the NVidia driver for instance has triggered a lot of these attempts. The NVidia driver is challenging on a lot of levels and has been something we have been constantly working on. There was technical issues for instance, like the NVidia driver and Mesa fighting over who owned the OpenGL.so implementation, which we fixed by the introduction glvnd a few years ago. But for a distro like Fedora that also cares deeply about free and open source software it also provided us with a lot of philosophical challenges. We had to answer the question of how could we on one side make sure our users had easy access to the driver without abandoning our principle around Fedora only shipping free software of out the box? I think we found a good compromise today where the NVidia driver is available in Fedora Workstation for easy install through GNOME Software, but at the same time default to Nouveau of the box. That said this is a part of the story where we are still hard at work to improve things further and while I am not at liberty to mention any details I think I can at least mention that we are meeting with our engineering counterparts at NVidia on almost a weekly basis to discuss how to improve things, not just for graphics, but around compute and other shared areas of interest. The most recent public result of that collaboration was of course the XWayland support in recent NVidia drivers, but I promise you that this is something we keep focusing on and I expect that we will be able to share more cool news and important progress over the course of the year, both for users of the NVidia binary driver and for users of Nouveau.

What are we still looking at in terms of addressing issues like this? Well one thing we are talking about is if there is value/need for a facility to install specific software based on hardware or software. For instance if we detect a high end gaming mouse connected to your system should we install Piper/ratbag or at least make GNOME Software suggest it? And if we detect that you installed Lutris and Steam are there other tools we should recommend you install, like the gamemode GNOME Shell extenion? It is a somewhat hard question to answer, which is why we are still pondering it, on one side it seems like a nice addition, but such connections would mean that we need to have a big database we constantly maintain which isn’t trivial and also having something running on your system to lets say check for those high end mice do add a little overhead that might be a waste for many users.

Another area that we are looking at is the issue of codecs. We did a big effort a couple of years ago and got AC3, mp3, AAC and mpeg2 video cleared for inclusion, and also got the OpenH264 implementation from Cisco made available. That solved a lot of issues, but today with so many more getting into media creation I believe we need to take another stab at it and for instance try to get reliable hardware accelerated encoding and decoding on video. I am not ready to announce anything, but we got a few ideas and leads we are looking at for how to move the needle there in a significant way.

So to summarize, I am not criticizing anyone for putting together what I call usecase distros, but at the same time I really want to get to a point where they are rarely needed, because we should be able to cater to most needs within the context of a general purpose Linux operating system. That said I do appreciate the effort of these distro makers both in terms of trying to help users have a better experience on linux and in indirectly helping us showcase both potential solutions or highlight the major pain points that still needs addressing in a general purpose Linux desktop operating system.

PipeWire and fixing the Linux Video Capture stack

Wim Taymans

Wim Taymans laying out the vision for the future of Linux multimedia


PipeWire has already made great strides forward in terms of improving the audio handling situation on Linux, but one of the original goals was to also bring along the video side of the house. In fact in the first few releases of Fedora Workstation where we shipped PipeWire we solely enabled it as a tool to handle screen sharing for Wayland and Flatpaks. So with PipeWire having stabilized a lot for audio now we feel the time has come to go back to the video side of PipeWire and work to improve the state-of-art for video capture handling under Linux. Wim Taymans did a presentation to our team inside Red Hat on the 30th of September talking about the current state of the world and where we need to go to move forward. I thought the information and ideas in his presentation deserved wider distribution so this blog post is building on that presentation to share it more widely and also hopefully rally the community to support us in this endeavour.

The current state of video capture, usually webcams, handling on Linux is basically the v4l2 kernel API. It has served us well for a lot of years, but we believe that just like you don’t write audio applications directly to the ALSA API anymore, you should neither write video applications directly to the v4l2 kernel API anymore. With PipeWire we can offer a lot more flexibility, security and power for video handling, just like it does for audio. The v4l2 API is an open/ioctl/mmap/read/write/close based API, meant for a single application to access at a time. There is a library called libv4l2, but nobody uses it because it causes more problems than it solves (no mmap, slow conversions, quirks). But there is no need to rely on the kernel API anymore as there are GStreamer and PipeWire plugins for v4l2 allowing you to access it using the GStreamer or PipeWire API instead. So our goal is not to replace v4l2, just as it is not our goal to replace ALSA, v4l2 and ALSA are still the kernel driver layer for video and audio.

It is also worth considering that new cameras are getting more and more complicated and thus configuring them are getting more complicated. Driving this change is a new set of cameras on the way often called MIPI cameras, as they adhere to the API standards set by the MiPI Alliance. Partly driven by this V4l2 is in active development with a Codec API addition, statefull/stateless, DMABUF, request API and also adding a Media Controller (MC) Graph with nodes, ports, links of processing blocks. This means that the threshold for an application developer to use these APIs directly is getting very high in addition to the aforementioned issues of single application access, the security issues of direct kernel access and so on.

libcamera logo


Libcamera is meant to be the userland library for v4l2.


Of course we are not the only ones seeing the growing complexity of cameras as a challenge for developers and thus libcamera has been developed to make interacting with these cameras easier. Libcamera provides unified API for setup and capture for cameras, it hides the complexity of modern camera devices, it is supported for ChromeOS, Android and Linux.
One way to describe libcamera is as the MESA of cameras. Libcamera provides hooks to run (out-of-process) vendor extensions like for image processing or enhancement. Using libcamera is considering pretty much a requirement for embedded systems these days, but also newer Intel chips will also have IPUs configurable with media controllers.

Libcamera is still under heavy development upstream and do not yet have a stable ABI, but they did add a .so version very recently which will make packaging in Fedora and elsewhere a lot simpler. In fact we have builds in Fedora ready now. Libcamera also ships with a set of GStreamer plugins which means you should be able to get for instance Cheese working through libcamera in theory (although as we will go into, we think this is the wrong approach).

Before I go further an important thing to be aware of here is that unlike on ALSA, where PipeWire can provide a virtual ALSA device to provide backwards compatibility with older applications using the ALSA API directly, there is no such option possible for v4l2. So application developers will need to port to something new here, be that libcamera or PipeWire. So what do we feel is the right way forward?

Ideal Linux Multimedia Stack

How we envision the Linux multimedia stack going forward


Above you see an illustration of what we believe should be how the stack looks going forward. If you made this drawing of what the current state is, then thanks to our backwards compatibility with ALSA, PulseAudio and Jack, all the applications would be pointing at PipeWire for their audio handling like they are in the illustration you see above, but all the video handling from most applications would be pointing directly at v4l2 in this diagram. At the same time we don’t want applications to port to libcamera either as it doesn’t offer a lot of the flexibility than using PipeWire will, but instead what we propose is that all applications target PipeWire in combination with the video camera portal API. Be aware that the video portal is not an alternative or a abstraction of the PipeWire API, it is just a way to set up the connection to PipeWire that has the added bonus of working if your application is shipping as a Flatpak or another type of desktop container. PipeWire would then be in charge of talking to libcamera or v42l for video, just like PipeWire is in charge of talking with ALSA on the audio side. Having PipeWire be the central hub means we get a lot of the same advantages for video that we get for audio. For instance as the application developer you interact with PipeWire regardless of if what you want is a screen capture, a camera feed or a video being played back. Multiple applications can share the same camera and at the same time there are security provided to avoid the camera being used without your knowledge to spy on you. And also we can have patchbay applications that supports video pipelines and not just audio, like Carla provides for Jack applications. To be clear this feature will not come for ‘free’ from Jack patchbays since Jack only does audio, but hopefully new PipeWire patchbays like Helvum can add video support.

So what about GStreamer you might ask. Well GStreamer is a great way to write multimedia applications and we strongly recommend it, but we do not recommend your GStreamer application using the v4l2 or libcamera plugins, instead we recommend that you use the PipeWire plugins, this is of course a little different from the audio side where PipeWire supports the PulseAudio and Jack APIs and thus you don’t need to port, but by targeting the PipeWire plugins in GStreamer your GStreamer application will get the full PipeWire featureset.

So what is our plan of action>
So we will start putting the pieces in place for this step by step in Fedora Workstation. We have already started on this by working on the libcamera support in PipeWire and packaging libcamera for Fedora. We will set it up so that PipeWire can have option to switch between v4l2 and libcamera, so that most users can keep using the v4l2 through PipeWire for the time being, while we work with upstream and the community to mature libcamera and its PipeWire backend. We will also enable device discoverer for PipeWire.

We are also working on maturing the GStreamer elements for PipeWire for the video capture usecase as we expect a lot of application developers will just be using GStreamer as opposed to targeting PipeWire directly. We will start with Cheese as our initial testbed for this work as it is a fairly simple application, using Cheese as a proof of concept to have it use PipeWire for camera access. We are still trying to decide if we will make Cheese speak directly with PipeWire, or have it talk to PipeWire through the pipewiresrc GStreamer plugin, but have their pro and cons in the context of testing and verifying this.

We will also start working with the Chromium and Firefox projects to have them use the Camera portal and PipeWire for camera support just like we did work with them through WebRTC for the screen sharing support using PipeWire.

There are a few major items we are still trying to decide upon in terms of the interaction between PipeWire and the Camera portal API. It would be tempting to see if we can hide the Camera portal API behind the PipeWire API, or failing that at least hide it for people using the GStreamer plugin. That way all applications get the portal support for free when porting to GStreamer instead of requiring using the Camera portal API as a second step. On the other side you need to set up the screen sharing portal yourself, so it would probably make things more consistent if we left it to application developers to do for camera access too.

What do we want from the community here?
First step is just help us with testing as we roll this out in Fedora Workstation and Cheese. While libcamera was written motivated by MIPI cameras, all webcams are meant to work through it, and thus all webcams are meant to work with PipeWire using the libcamera backend. At the moment that is not the case and thus community testing and feedback is critical for helping us and the libcamera community to mature libcamera. We hope that by allowing you to easily configure PipeWire to use the libcamera backend (and switch back after you are done testing) we can get a lot of you to test and let us what what cameras are not working well yet.

A little further down the road please start planning moving any application you maintain or contribute to away from v4l2 API and towards PipeWire. If your application is a GStreamer application the transition should be fairly simple going from the v4l2 plugins to the pipewire plugins, but beyond that you should familiarize yourself with the Camera portal API and the PipeWire API for accessing cameras.

For further news and information on PipeWire follow our @PipeWireP twitter account and for general news and information about what we are doing in Fedora Workstation make sure to follow me on twitter @cfkschaller.
PipeWire

Fedora Workstation: Our Vision for Linux Desktop

Fedora Workstation
So I have spoken about what is our vision for Fedora Workstation quite a few times before, but I feel it is often useful to get back to it as we progress with our overall effort.So if you read some of my blog posts about Fedora Workstation over the last 5 years, be aware that there is probably little new in here for you. If you haven’t read them however this is hopefully a useful primer on what we are trying to achieve with Fedora Workstation.

The first few years after we launched Fedora Workstation in 2014 we focused on lot on establishing a good culture around what we where doing with Fedora, making sure that it was a good day to day desktop driver for people, and not just a great place to develop the operating system itself. I think it was Fedora Project Lead Matthew Miller who phrased it very well when he said that we want to be Leading Edge, not Bleeding Edge. We also took a good look at the operating system from an overall stance and tried to map out where Linux tended to fall short as a desktop operating system and also tried to ask ourselves what our core audience would and should be. We refocused our efforts on being a great Operating System for all kinds of developers, but I think it is fair to say that we decided that was to narrow a wording as our efforts are truly to reach makers of all kinds like graphics artists and musicians, in addition to coders. So I thought I go through our key pillar efforts and talk about where they are at and where they are going.

Flatpak

Flatpak logo
One of the first things we concluded was that our story for people who wanted to deploy applications to our platform was really bad. The main challenge was that the platform was moving very fast and it was a big overhead for application developers to keep on top of the changes. In addition to that, since the Linux desktop is so fragmented, the application developers would have to deal with the fact that there was 20 different variants of this platform, all moving at a different pace. The way Linux applications was packaged, with each dependency being packaged independently of the application created pains on both sides, for the application developer it means the world kept moving underneath them with limited control and for the distributions it meant packaging pains as different applications who all depended on the same library might work or fail with different versions of a given library. So we concluded we needed a system which allowed us to decouple of application from the host OS to let application developers update their platform at a pace of their own choosing and at the same time unify the platform in the sense that the application should be able to run without problems on the latest Fedora releases, the latest RHEL releases or the latest versions of any other distribution out there. As we looked at it we realized there was some security downsides compared to the existing model, since the Os vendor would not be in charge of keeping all libraries up to date and secure, so sandboxing the applications ended up a critical requirement. At the time Alexander Larsson was working on bringing Docker to RHEL and Fedora so we tasked him with designing the new application model. The initial idea was to see if we could adjust Docker containers to the desktop usecase, but Docker containers as it stood at that time were very unsuited for the purpose of hosting desktop applications and our experience working with the docker upstream at the time was that they where not very welcoming to our contributions. So in light of how major the changes we would need to implement and the unlikelyhood of getting them accepted upstream, Alex started on what would become Flatpak. Another major technology that was coincidentally being developed at the same time was OSTree by Colin Walters. To this day I think the best description of OSTree is that it functions as a git for binaries, meaning it allows you a simple way to maintain and update your binary applications with minimally sized updates. It also provides some disk deduplication which we felt was important due to the duplication of libraries and so on that containers bring with them. Finally another major design decision Alex did was that the runtime/baseimage should be hosted outside the container, so make possible to update the runtime independently of the application with relevant security updates etc.

Today there is a thriving community around Flatpaks, with the center of activity being flathub, the Flatpak application repository. In Fedora Workstation 35 you should start seeing Flatpak from Flathub being offered as long as you have 3rd party repositories enabled. Also underway is Owen Taylor leading our efforts of integrating Flatpak building into the internal tools we use at Red Hat for putting RHEL together, with the goal of switching over to Flatpaks as our primary application delivery method for desktop applications in RHEL and to help us bridge the Fedora and RHEL application ecosystem.

You can follow the latest news from Flatpak through the official Flatpak twitter account.

Silverblue

So another major issue we decided needing improvements was that of OS upgrades (as opposed to application updates). The model pursued by Linux distros since their inception is one of shipping their OS as a large collection of independently packaged libraries. This setup is inherently fragile and requires a lot of quality engineering and testing to avoid problems, but even then sometimes things sometimes fail, especially in a fast moving OS like Fedora. A lot of configuration changes and updates has traditionally been done through scripts and similar, making rollback to an older version in cases where there is a problem also very challenging. Adventurous developers could also have done changes to their own copy of the OS that would break the upgrade later on. So thanks to all the great efforts to test and verify upgrades they usually go well for most users, but we wanted something even more sturdy. So the idea came up to move to a image based OS model, similar to what people had gotten used to on their phones. And OSTree once again became the technology we choose to do this, especially considering it was being used in Red Hat first foray into image based operating systems for servers (the server effort later got rolled into CoreOS as part of Red Hat acquiring CoreOS). The idea is that you ship the core operating system as a singular image and then to upgrade you just replace that image with a new image, and thus the risks of problems are greatly reduced. On top of that each of those images can be tested and verified as a whole by your QE and test teams. Of course we realized that a subset of people would still want to be able to tweak their OS, but once again OSTree came to our rescue as it allows developers to layer further RPMS on top of the OS image, including replacing current system libraries with for instance newer ones. The great thing about OSTree layering is that once you are done testing/using the layers RPMS you can with a very simple command just drop them again and go back to the upstream image. So combined with applications being shipped as Flatpaks this would create an OS that is a lot more sturdy, secure and simple to update and with a lot lower chance of an OS update breaking any of your applications. On top of that OSTree allows us to do easy OS rollbacks, so if the latest update somehow don’t work for you can you quickly rollback while waiting for the issue you are having to be fixed upstream. And hence Fedora Silverblue was born as the vehicle for us to develop and evolve an image based desktop operating system.

You can follow our efforts around Silverblue through the offical Silverblue twitter account.

Toolbx

Toolbox with RHEL

Toolbox pet container with RHEL UBI


So Flatpak helped us address a lot of the the gaps for making a better desktop OS on the application side and Silverblue was the vehicle for our vision on the OS side, but we realized that we also needed some way for all kinds of developers to be able to easily take advantage of the great resource that is the Fedora RPM package universe and the wider tools universe out there. We needed something that provided people with a great terminal experience. We had already been working on various smaller improvements to the terminal for a while, but we realized we needed something a lot more substantial. Accessing an immutable OS like Silverblue through a terminal window tends to be quite limiting. So that it is usually not want you want to do and also you don’t want to rely on the OSTree layering for running all your development tools and so on as that is going to be potentially painful when you upgrade your OS.
Luckily the container revolution happening in the Linux world pointed us to the solution here too, as while containers were rolled out the concept of ‘pet containers’ were also born. The idea of a pet container is that unlike general containers (sometimes refer to as cattle containers) pet container are containers that you care about on an individual level, like your personal development environment. In fact pet containers even improves on how we used to do things as they allow you to very easily maintain different environments for different projects. So for instance if you have two projects, hosted in two separate pet containers, where the two project depends on two different versions of python, then containers make that simple as it ensures that there is no risk of one of your projects ‘contaminating’ the others with its dependencies, yet at the same time allow you to grab RPMS or other kind of packages from upstream resources and install them in your container. In fact while inside your pet container the world feels a lot like it always has when on the linux command line. Thanks to the great effort of Dan Walsh and his team we had a growing number of easy to use container tools available to us, like podman. Podman is developed with the primary usecase being for running and deploying your containers at scale, managed by OpenShift and Kubernetes. But it also gave us the foundation we needed for Debarshi Ray to kicked of the Toolbx project to ensure that we had an easy to use tool for creating and managing pet containers. As a bonus Toolbx allows us to achieve another important goal, to allow Fedora Workstation users to develop applications against RHEL in a simple and straightforward manner, because Toolbx allows you to create RHEL containers just as easy as it allows you to create Fedora containers.

You can follow our efforts around Toolbox on the official Toolbox twitter account

Wayland

Ok, so between Flatpak, Silverblue and Toolbox we have the vision clear for how to create a robust OS, with a great story for application developers to maintain and deliver applications for it, to Toolbox providing a great developer story on top of this OS. But we also looked at the technical state of the Linux desktop and realized that there where some serious deficits we needed to address. One of the first one we saw was the state of graphics where X.org had served us well for many decades, but its age was showing and adding new features as they came in was becoming more and more painful. Kristian Høgsberg had started work on an alternative to X while still at Red Hat called Wayland, an effort he and a team of engineers where pushing forward at Intel. There was a general agreement in the wider community that Wayland was the way forward, but apart from Intel there was little serious development effort being put into moving it forward. On top of that, Canonical at the time had decided to go off on their own and develop their own alternative architecture in competition with X.org and Wayland. So as we were seeing a lot of things happening in the graphics space horizon, like HiDPI, and also we where getting requests to come up with a way to make Linux desktops more secure, we decided to team up with Intel and get Wayland into a truly usable state on the desktop. So we put many of our top developers, like Olivier Fourdan, Adam Jackson and Jonas Ådahl, on working on maturing Wayland as quickly as possible.
As things would have it we also ended up getting a lot of collaboration and development help coming in from the embedded sector, where companies such as Collabora was helping to deploy systems with Wayland onto various kinds of embedded devices and contributing fixes and improvements back up to Wayland (and Weston). To be honest I have to admit we did not fully appreciate what a herculean task it would end up being getting Wayland production ready for the desktop and it took us quite a few Fedora releases before we decided it was ready to go. As you might imagine dealing with 30 years of technical debt is no easy thing to pay down and while we kept moving forward at a steady pace there always seemed to be a new batch of issues to be resolved, but we managed to do so, not just by maturing Wayland, but also by porting major applications such as Martin Stransky porting Firefox, and Caolan McNamara porting LibreOffice over to Wayland. At the end of the day I think what saw us through to success was the incredible collaboration happening upstream between a large host of individual contributors, companies and having the support of the X.org community. And even when we had the whole thing put together there where still practical issues to overcome, like how we had to keep defaulting to X.org in Fedora when people installed the binary NVidia driver because that driver did not work with XWayland, the X backwards compatibility layer in Wayland. Luckily that is now in the process of becoming a thing of the past with the latest NVidia driver updates support XWayland and us working closely with NVidia to ensure driver and windowing stack works well.

PipeWire

Pipewire in action

Example of PipeWire running


So now we had a clear vision for the OS and a much improved and much more secure graphics stack in the form of Wayland, but we realized that all the new security features brought in by Flatpak and Wayland also made certain things like desktop capturing/remoting and web camera access a lot harder. Security is great and critical, but just like the old joke about the most secure computer being the one that is turned off, we realized that we needed to make sure these things kept working, but in a secure and better manner. Thankfully we have GStreamer co-creator Wim Taymans on the team and he thought he could come up with a pulseaudio equivalent for video that would allow us to offer screen capture and webcam access in a convenient and secure manner.
As Wim where prototyping what we called PulseVideo at the time we also started discussing the state of audio on Linux. Wim had contributed to PulseAudio to add a security layer to it, to make for instance it harder for a rogue application to eavesdrop on you using your microphone, but since it was not part of the original design it wasn’t a great solution. At the same time we talked about how our vision for Fedora Workstation was to make it the natural home for all kind of makers, which included musicians, but how the separateness of the pro-audio community getting in the way of that, especially due to the uneasy co-existence of PulseAudio on the consumer side and Jack for the pro-audio side. As part of his development effort Wim came to the conclusion that he code make the core logic of his new project so fast and versatile that it should be able to deal with the low latency requirements of the pro-audio community and also serve its purpose well on the consumer audio and video side. Having audio and video in one shared system would also be an improvement for us in terms of dealing with combined audio and video sources as guaranteeing audio video sync for instance had often been a challenge in the past. So Wims effort evolved into what we today call PipeWire and which I am going to be brave enough to say has been one of the most successful launches of a major new linux system component we ever done. Replacing two old sound servers while at the same time adding video support is no small feat, but Wim is working very hard on fixing bugs as quickly as they come in and ensure users have a great experience with PipeWire. And at the same time we are very happy that PipeWire now provides us with the ability of offering musicians and sound engineers a new home in Fedora Workstation.

You can follow our efforts on PipeWire on the PipeWire twitter account.

Hardware support and firmware

In parallel with everything mentioned above we where looking at the hardware landscape surrounding desktop linux. One of the first things we realized was horribly broken was firmware support under Linux. More and more of the hardware smarts was being found in the firmware, yet the firmware access under Linux and the firmware update story was basically non-existent. As we where discussing this problem internally, Peter Jones who is our representative on UEFI standards committee, pointed out that we probably where better poised to actually do something about this problem than ever, since UEFI was causing the firmware update process on most laptops and workstations to become standardized. So we teamed Peter up with Richard Hughes and out of that collaboration fwupd and LVFS was born. And in the years since we launched that we gone from having next to no firmware available on Linux (and the little we had only available through painful processes like burning bootable CDs etc.) to now having a lot of hardware getting firmware update support and more getting added almost on a weekly basis.
For the latest and greatest news around LVFS the best source of information is Richard Hughes twitter account.

In parallel to this Adam Jackson worked on glvnd, which provided us with a way to have multiple OpenGL implementations on the same system. For those who has been using Linux for a while I am sure you remembers the pain of the NVidia driver and Mesa fighting over who provided OpenGL on your system as it was all tied to a specific .so name. There was a lot of hacks being used out there to deal with that situation, of varying degree of fragility, but with the advent of glvnd nobody has to care about that problem anymore.

We also decided that we needed to have a part of the team dedicated to looking at what was happening in the market and work on covering important gaps. And with gaps I mean fixing the things that keeps the hardware vendors from being able to properly support Linux, not writing drivers for them. Instead we have been working closely with Dell and Lenovo to ensure that their suppliers provide drivers for their hardware and when needed we work to provide a framework for them to plug their hardware into. This has lead to a series of small, but important improvements, like getting the fingerprint reader stack on Linux to a state where hardware vendors can actually support it, bringing Thunderbolt support to Linux through Bolt, support for high definition and gaming mice through the libratbag project, support in the Linux kernel for the new laptop privacy screen feature, improved power management support through the power profiles daemon and now recently hiring a dedicated engineer to get HDR support fully in place in Linux.

Summary

So to summarize. We are of course not over the finish line with our vision yet. Silverblue is a fantastic project, but we are not yet ready to declare it the official version of Fedora Workstation, mostly because we want to give the community more time to embrace the Flatpak application model and for developers to embrace the pet container model. Especially applications like IDEs that cross the boundary between being in their own Flatpak sandbox while also interacting with things in your pet container and calling out to system tools like gdb need more work, but Christian Hergert has already done great work solving the problem in GNOME Builder while Owen Taylor has put together support for using Visual Studio Code with pet containers. So hopefully the wider universe of IDEs will follow suit, in the meantime one would need to call them from the command line from inside the pet container.

The good thing here is that Flatpaks and Toolbox also works great on traditional Fedora Workstation, you can get the full benefit of both technologies even on a traditional distribution, so we can allow for a soft and easy transition.

So for anyone who made it this far, appoligies for this become a little novel, that was not my intention when I started writing it :)

Feel free to follow my personal twitter account for more general news and updates on what we are doing around Fedora Workstation.
Christian F.K. Schaller photo

Cool happenings in Fedora Workstation land

Been some time since my last update, so I felt it was time to flex my blog writing muscles again and provide some updates of some of the things we are working on in Fedora in preparation for Fedora Workstation 35. This is not meant to be a comprehensive whats new article about Fedora Workstation 35, more of a listing of some of the things we are doing as part of the Red Hat desktop team.

NVidia support for Wayland
One thing we spent a lot of effort on for a long time now is getting full support for the NVidia binary driver under Wayland. It has been a recurring topic in our bi-weekly calls with the NVidia engineering team ever since we started looking at moving to Wayland. There has been basic binary driver support for some time, meaning you could run a native Wayland session on top of the binary driver, but the critical missing piece was that you could not get support for accelerated graphics when running applications through XWayland, our X.org compatibility layer. Which basically meant that any application requiring 3D support and which wasn’t a native Wayland application yet wouldn’t work. So over the last Months we been having a great collaboration with NVidia around closing this gap, with them working closely with us in fixing issues in their driver while we have been fixing bugs and missing pieces in the rest of the stack. We been reporting and discussing issues back and forth allowing us a very quickly turnaround on issues as we find them which of course all resulted in the NVidia 470.42.01 driver with XWayland support. I am sure we will find new corner cases that needs to be resolved in the coming Months, but I am equally sure we will be able to quickly resolve them due to the close collaboration we have now established with NVidia. And I know some people will wonder why we spent so much time working with NVidia around their binary driver, but the reality is that NVidia is the market leader, especially in the professional Linux workstation space, and there are lot of people who either would end up not using Linux or using Linux with X without it, including a lot of Red Hat customers and Fedora users. And that is what I and my team are here for at the end of the day, to make sure Red Hat customers are able to get their job done using their Linux systems.

Lightweight kiosk mode
One of the wonderful things about open source is the constant flow of code and innovation between all the different parts of the ecosystem. For instance one thing we on the RHEL side have often been asked about over the last few years is a lightweight and simple to use solution for people wanting to run single application setups, like information boards, ATM machines, cash registers, information kiosks and so on. For many use cases people felt that running a full GNOME 3 desktop underneath their application was either to resource hungry and or created a risk that people accidentally end up in the desktop session. At the same time from our viewpoint as a development team we didn’t want a completely separate stack for this use case as that would just increase our maintenance burden as we would end up having to do a lot of things twice. So to solve this problem Ray Strode spent some time writing what we call GNOME Kiosk mode which makes setting up a simple session running single application easy and without running things like the GNOME shell, tracker, evolution etc. This gives you a window manager with full support for the latest technologies such as compositing, libinput and Wayland, but coming in at about 18MB, which is about 71MB less than a minimal GNOME 3 desktop session. You can read more about the new Kiosk mode and how to use it in this great blog post from our savvy Edge Computing Product Manager Ben Breard. The kiosk mode session described in Ben’s article about RHEL will be available with Fedora Workstation 35.

high-definition mouse wheel support
A major part of what we do is making sure that Red Hat Enterprise Linux customers and Fedora users get hardware support on par with what you find on other operating systems. We try our best to work with our hardware partners, like Lenovo, to ensure that such hardware support comes day and date with when those features are enabled on other systems, but some things ends up taking longer time for various reasons. Support for high-definition mouse wheels was one of those. Peter Hutterer, our resident input expert, put together a great blog post explaining the history and status of high-definition mouse wheel support. As Peter points out in his blog post the feature is not yet fully supported under Wayland, but we hope to close that gap in time for Fedora Workstation 35.

Mouse with hires mouse

Mouse with HiRes scroll wheel

PipeWire
I feel I can’t do one of these posts without talking about latest developments in PipeWire, our unified audio and video server. Wim Taymans keeps working with rapidly growing PipeWire community to fix issues as they are reported and add new features to PipeWire. Most recently Wims focus has been on implementing support for S/PDIF passthrough support over both S/PDIF and HDMI connections. This will allow us to send undecoded data over such connections which is critical for working well with surround sound systems and soundbars. Also the PipeWire community has been working hard on further improving the Bluetooth support with bluetooth battery status support for head-set profile and using Apple extensions. aptX-LL and FastStream codec support was also added. And of course a huge amount of bug fixes, it turns out that when you replace two different sound servers that has been around for close to two decades there are a lot of corner cases to cover :). Make sure to check out two latest release notes for 0.3.35 and for 0.3.36 for details.

Screenshot of Easyeffects

EasyEffects is a great example of a cool new application built with PipeWire

Privacy screen
Another feature that we have been working on as a result of our Lenovo partnership is Privacy screen support. For those not familiar with this technology it is basically to allow you to reduce the readability of your screen when viewed from the side, so that if you are using your laptop at a coffee shop for instance then a person sitting close by will have a lot harder time trying to read what is on your screen. Hans de Goede has been shepherding the kernel side of this forward working with Marco Trevisan from Canonical on the userspace part of it (which also makes this a nice example of cross-company collaboration), allowing you to turn this feature on or off. This feature though is not likely to fully land in time for Fedora Workstation 35 so we are looking at if we will bring this in as an update to Fedora Workstation 35 or if it will be a Fedora Workstation 36 feature.

Penny

zink inside

Zink inside the penny


As most of you know the future of 3D graphics on Linux is the Vulkan API from the Khronos Group. This doesn’t mean that OpenGL is going away anytime soon though, as there is a large host of applications out there using this API and for certain types of 3D graphics development developers might still choose to use OpenGL over Vulkan. Of course for us that creates a little bit of a challenge because maintaining two 3D graphics interfaces is a lot of work, even with the great help and contributions from the hardware makers themselves. So we been eyeing the Zink project for a while, which aims at re-implementing OpenGL on top of Vulkan, as a potential candidate for solving our long term needs to support the OpenGL API, but without drowning us in work while doing so. The big advantage to Zink is that it allows us to support one shared OpenGL implementation across all hardware and then focus our HW support efforts on the Vulkan drivers. As part of this effort Adam Jackson has been working on a project called Penny.

Zink implements OpenGL in terms of Vulkan, as far as the drawing itself is concerned, but presenting that drawing to the rest of the system is currently system-specific (GLX). For hardware that already has a Mesa driver, we use GBM. On NVIDIA’s Vulkan (and probably any other binary stacks on Linux, and probably also like WSL or macOS + MoltenVK) we download the image from the GPU back to the CPU and then use the same software upload/display path as llvmpipe, which as you can imagine is Not Fast.

Penny aims to extend Zink by replacing both of those paths, and instead using the various Vulkan WSI extensions to manage presentation. Even for the GBM case this should enable higher performance since zink will have more information about the rendering pipeline (multisampling in particular is poorly handled atm). Future window system integration work can focus on Vulkan, with EGL and GLX getting features “for free” once they’re enabled in Vulkan.

3rd party software cleanup
Over time we have been working on adding more and more 3rd party software for easy consumption in Fedora Workstation. The problem we discovered though was that due to this being done over time, with changing requirements and expectations, the functionality was not behaving in a very intuitive way and there was also new questions that needed to be answered. So Allan Day and Owen Taylor spent some time this cycle to review all the bits and pieces of this functionality and worked to clean it up. So the goal is that when you enable third-party repositories in Fedora Workstation 35 it behaves in a much more predictable and understandable way and also includes a lot of applications from Flathub. Yes, that is correct you should be able to install a lot of applications from Flathub in Fedora Workstation 35 without having to first visit the Flathub website to enable it, instead they will show up once you turned the knob for general 3rd party application support.

Power profiles
Another item we spent quite a bit of time for Fedora Workstation 35 is making sure we integrate the Power Profiles work that Bastien Nocera has been working on as part of our collaboration with Lenovo. Power Profiles is basically a feature that allows your system to behave in a smarter way when it comes to power consumption and thus prolongs your battery life. So for instance when we notice you are getting low on battery we can offer you to go into a strong power saving mode to prolong how long you can use the system until you can recharge. More in-depth explanation of Power profiles in the official README.

Wayland
I usually also have ended up talking about Wayland in my posts, but I expect to be doing less going forward as we have now covered all the major gaps we saw between Wayland and X.org. Jonas Ådahl got the headless support merged which was one of our big missing pieces and as mentioned above Olivier Fourdan and Jonas and others worked with NVidia on getting the binary driver with XWayland support working with GNOME Shell. Of course this being software we are never truly done, there will of course be new issues discovered, random bugs that needs to be fixed, and of course also new features that needs to be implemented. We already have our next big team focus in place, HDR support, which will need work from the graphics drivers, up through Mesa, into the window manager and the GUI toolkits and in the applications themselves. We been investigating and trying out some things for a while already, but we are now ready to make this a main focus for the team. In fact we will soon be posting a new job listing for a fulltime engineer to work on HDR vertically through the stack so keep an eye out for that if you are interested in working on this. The job will be open to candidates who which to work remotely, so as long as Red Hat has a business presence in the country you live we should be able to offer you the job if you are the right candidate for us. Update:Job listing is now online for our HDR engineer.

BTW, if you want to see future updates and keep on top of other happenings from Fedora and Red Hat in the desktop space, make sure to follow me on twitter.

New opportunities in the Red Hat Desktop team

So we are looking to hire quite a few people into the Desktop team currently. First of all we are looking to hire two graphics engineers to help us work on Linux Graphics drivers. The first of those two jobs is now online on the Red Hat jobs site. This is a job in our core graphics team focusing on RHEL, Fedora and upstream around the Intel, AMD and NVidia open source drivers. This is an opportunity to join a team of incredibly talented engineers working on everything from the graphics system of the Linux kernel and on the userspace bits like Vulkan, OpenGL and Wayland.  The job is listed as Senior Engineer, but for the right candidate we have flexibility there. We also have flexibility for people who want to work remotely, so as long as there is a Red Hat office in your home country you can work remotely for us.  The second job, which we hope to have up soon, will be looking more at ARM graphics and be tied to our automotive effort, but we will be looking at the applications for either position in combination so feel free to apply for the already listed job even if you are more interested in the second one as we will discuss both jobs with potential candidates.

The second job we have up is for – Software Engineer – GPU, Input and Multimedia which is also for joining our Graphics team. This job is targetted at our  office in Brno, Czechia and is a great entry level position if you are interested in the field of graphics. The job listing can be found here and outlines the kind of things we want you to look at, but do expect initially your job will be focused on helping the rest of the team manage their backlog and then grow from there.

The last job we have online now is for the automotive team, where we are looking for someone at the Senior/Principal level to join our Infotainment team, working with car makers around issues related to multimedia and help identifying needs and gaps and then work with upstream communities to figure out how we can resolve those issues. The job is targeted at Madrid, Spain as it is where we hope to center some of the infotainment effort and it makes things easier in terms of hardware access and similar, but for the right candidate we might be open to looking for candidates wanting to work remote or in another Red Hat office. You can find this job listing here.

We expect to be posting further jobs for the infotainment team within a week or two, so I will update once they are up.

What to look for in Fedora Workstation 34

As we are heading towards April and the release of Fedora Workstation 34 I wanted to post an update on what we are working on for this release and what we are looking at going forward. 2020 was a year where we focused a lot on polishing what we had and getting things past the finish line and Fedora Workstation 34 is going to be the culmination of that effort in many ways.

Wayland:
The big ticket item we have wanted to close off on was Wayland, because while Wayland has been production ready for most of us for a while, there was still some cases it didn’t cover as well as X.org. The biggest of this was of course the lack of accelerated XWayland support with the binary NVidia driver. Fixing that issue of course wasn’t something we could do ourselves, but we have been working diligently with our friends at NVidia to help ensure everything was in place for them to enable that support in their driver, so I have been very happy to see the public reports confirming that NVidia will have accelerated 3D in the summer release of their driver. The other Wayland area we have put a lot of effort into has been the work undertaken by Jonas Ådahl to get headless display support working with Wayland. This is a critical feature for people who for instance want a desktop instance on their servers or in the cloud, who want a desktop they access through things like VNC or RDP to use for sysadmin related tasks. Jonas spent a lot of time laying the groundwork for this over the course of last year and we are now in the final stages of merging the patches to enable this feature in GNOME and Wayland in preparation for Fedora Workstation 34. Once those two items are out we consider our Wayland rampup/rollout to be complete, so while there of course will continue to be bugfixes and new features implemented, that will be part of a natural evolution of Wayland and not part of a ‘close gaps with X11’ effort like now.

PipeWire
Another big ticket item we are hoping to release fully in Fedora Workstation 34 is PipeWire. PipeWire as most of you know is the engine we use to deal with handling video streams in a secure and shareable away in Fedora Workstation, so when you interact with your web camera(s) or do screen casting or make screenshots it is all routed and handled by PipeWire. But in Fedora Workstation 34 we are aiming to also switch to using PipeWire for audio, to replace both PulseAudio and Jack. For those of you who had read any previous blog post from me you will know what an important step forward this will be as we would finally be making the pro-audio community first class citizens in Fedora Workstation and Linux in general. When we decided to try to switch to PipeWire in Fedora Workstation 34 I have to admit I was a little skeptical about if we would be able to get all things ready in time as there are so many things that needs to be tested and fixed when you switch out such a critical component. Up to that point we had a lot of people interested in PipeWire, but only limited community involvement, but I feel the announcement of bringing in PipeWire for Fedora Workstation 34 galvanized the community around the project and we now have a very active community around PipeWire in #pipewire on the freenode IRC network. Not only is Wim Taymans getting a ton of help with testing and verification, but we also see a stead stream of patches coming in, with for instance improved Bluetooth audio support being contributed, in fact I believe that PipeWire will be able to usher in better bluetooth audio support in Fedora than we ever had before, with great support for high quality Bluetooth audio codecs like LDAC.

I am especially happy to see so many of the key members of the pro-audio Linux community taking part in this effort and is of course also happy to see many pro-audio folks testing Fedora Workstation for the first time due to this effort. The community is working closely with Wim to test and verify as many important ProAudio applications as possible and work to update Fedora packaging as needed to ensure they can transition from Jack to PipeWire without dependency conflicts or issues. One last item to mention here is that you might have seen that Red Hat is getting into the automotive space, I can’t share a lot of details about that effort, but one thing I can say is that PipeWire will be a core part of it and thus we will soon be looking to hire more engineers to work on PipeWire, so if that is of interest to you be sure to track my twitter feed or blog as I will announce our job openings there as they become available. For the community at large this should be great too as it means that we can get a lot of synergy between automotive and the desktop around audio and video handling.

It is still somewhat of an open question if we end up actually switching to PipeWire in Fedora Workstation 34, but things are looking good at this point in time and worst case scenario it will be in place for Fedora Workstation 35.

Toolbox
Toolbox is another effort that is in a great spot now. Toolbox is our tool for making working with pet containers a breeze for developers. The initial version was prototyped quickly by writing it as a shell script, but we spent time last year getting it rewritten in Go in order to make it possible to keep expanding the project and allow us to implement all the things we envision for it. With that done feature work is now in focus again and Ondřej Michal has done some great work making it possible to set up RHEL containers in Toolbox. This means that you can run Fedora on your laptop and get the latest and greatest features that way, but you can do your development in a RHEL pet container, so you get an environment identical to what you applications will see once they are deployed into the cloud or onto company hardware. This gives you the best of both worlds in my opinion, the fast moving Fedora Workstation that brings the most out of our laptop and desktop hardware, but still easy access to the RHEL platform for development and testing. You can even test this today on Fedora Workstation 33, just open a terminal and type ‘toolbox create --distro rhel --release 8.3‘. The resulting toolbox will then be based on RHEL and not Fedora and thus perfect for doing RHEL targeted development. You will need to use the subscription-manager tool to register it (be sure to register on developer.redhat.com for your free RHEL developer subscription. Over time we hope to integrate this into GNOME Online accounts like we do for the RHEL virtual machines you can set up with GNOME Boxes, so that once you set up your RHEL account you can create RHEL virtual machines and RHEL containers easily on Fedora Workstation.

Toolbox with RHEL

Toolbox pet container with RHEL UBI

Flatpak
Owen Taylor has been doing some incredible work behind the scenes for the last year trying to ensure the infrastructure we have in RHEL and Fedora provides a great integrated Flatpak experience. As we move forward we expect Flatpaks to be the primary packaging format that Fedora users consume their applications in, but to make that a reality we needed to ensure the experience is good both for Fedora maintainers and for the end users. So one of the big ticket items Owen been working on is getting incremental updates working in Fedora. If you have used applications from Flathub you probably noticed that their updates are small and nimble despite being packaged as Flatpak containers, while the Fedora flatpaks causes big updates each time. The reason for this is that the Fedora flatpaks are shipping as OCI (Open Container Initiative) images, while the Flatpaks on Flathub are shipping as OStree repositories (if you don’t know OStree, think of it as git for binaries). So shipping the Flatpaks as OCI images has advantages in the form of being the same format we at Red Hat use for our kubernetes/docker/openshift containers and thus it allows us to reuse a lot of the work that Red Hat as put into ensuring we can provide and keep such containers up to date and secure, but the downside until now has been that these containers where shipped in a way which cause each update, no matter how small the change, to be a full re-download of the whole image. Well Owen Taylor and Alex Larsson worked together to resolve this and came up with a method to allow incremental updates of such containers and thus bring the update sizes in line with what you see on Flathub for Flatpaks. This should be deployed in time for Fedora Workstation 34 and we also hope to  eventually deploy it for  kubernetes/docker containers too. Finally to make even more applications available we are doing work to enable people to get access to Flathub.org out of the box in Fedora when you enable 3rd party repositories in initial setup, so that your our of the box application selection will be even bigger.

Flathub frontpage

Flathub webpage

GNOME 40
Another major change in Fedora Workstation 34 is GNOME40 which contains a revamp of the GNOME 3 user interface. This was a collaborative effort between a lot of GNOME 3 stakeholders with Allan Day representing Red Hat. This was also an effort by the GNOME design community to up their game and thus as part of the development process the GNOME Foundation paid a professional company to do user testing on the proposed changes and some of the alternatives. This means that the changes where verified to actually be experienced as an improvement for the experienced GNOME user participants and that it felt intuitive for new users of GNOME. One advantage we have in Fedora is that since we don’t do major tweaking of the GNOME user interface which means once Fedora Workstation 34 ships you are set to enjoy the new GNOME experience from day one. For long time GNOME users I hope and expect that the updates will be a welcome refresh and at the same time that the changes provide a more easy onramp for new GNOME and Fedora Workstation users. Some of the early versions did lead some long term fans of how multimonitor support in GNOME3 worked to be a bit concerned, but be assured that multi monitor is a critical usecase in our opinion and something we have been looking at and will be looking at keep improving. In fact Allan Day wrote a great blog post about GNOME40 multimonitor support recently to explain what we are doing and how we see it evolving going forward.

Input
Another area where we keep putting in a lot of effort is input. Thanks to Peter Hutterer and Benjamin Tissoires we keep making sure Fedora Workstation and the world of Linux keeps having access to the newest and best in input. The latest effort they are working on has been to enable haptic touchpads. Haptics touchpads should be familiar among people who tried Apple hardware, but they are expected to appear in force on laptops in general this year, so we have been putting in the effort to ensure that we can support this new type of device as they come out. So if you see laptops you want with haptic touchpads then Fedora Workstation should be ready for it, but of course until these devices are commonplace and we had a chance to test and verify I can make no guarantees.

Another major effort that we undertook in relation to input was move the GNOME input to a separate thread. Carlos Garnacho worked on this patch to make that happen. This should provide a smoother experience with Fedora Workstation 34 as it means the mouse should not stall due to the main thread running Wayland being busy. This was done as part of the overall performance work we been continuously doing over the last years to ensure to address performance issues and make Fedora and GNOME have the best performance and performance related behaviour possible.

Lenovo Laptops
So one of the major announcements of last year was Lenovo Laptops with Fedora Linux pre-installed. There are currently two models available with Linux, the X1 Carbon and the Lenovo P1. Between them they cover the two most commons requests we see, a ultralight weight laptop with the X1 and a more powerful ‘portable workstation’ model with the P1. We are working on a couple of more models and also to get them sold globally, which was key goal of the effort. Be aware that both models are on sale as I am writing this (hopefully still true when you read this), so it is a good time to grab a great laptop with a great OS.

Lenovo P1

Lenovo P1

Vision
So one thing I wanted to do to is tie the work we do in Fedora Workstation together by articulating what we are trying to achieve. Fedora has for the longest time been the place where Linux as an operating system is evolving and being developed. There are very few major innovations that has come to Linux that hasn’t been developed and incubated in Fedora by Fedora contributors, including of course Red Hat. This include things like the Linux Vendor Firmware Service, Wayland, Flatpak, SilverBlue, PipeWire, SystemD, flicker free boot, HiDPI support, gaming mouse support and so much more. We have always done this work in close cooperation with the upstreams we are collaborating with, which is why the patch delta in any given Fedora release is small. We work hard to get improvements into the upstream kernel and into GNOME and so on right away, to avoid needing to ship downstream patches in Fedora. That of course saves us from having to maintain temporary forks, but more importantly it is the right way to collaborate with an open source community.

So looking back to when we launched Fedora Workstation we realized that being at the front like that had come at the cost of not being stable and user friendly. So the big question we tried to ask ourselves when launching Fedora Workstation and the question that still drives a lot of our decision making and focus is : how can we preserve being the heart and center of Linux OS development, but at the same time provide end users with a stable and well functioning system? To achieve that we have done lot of changes over the last years, ranging from some policy changes in terms of how and when we brought changes into Fedora, but maybe even more importantly we focused on a lot on figuring out ways to reduce the challenges caused by a rapidly evolving OS, like the introduction of Flatpaks to allow applications to be developed and released without strong ties to the host system libraries and with the concepts we are maturing in Silverblue around image based operating systems or how we are looking at pet container development with Toolbox. All of these things combined remove a lot of the fragility we seen in Linux up to this point and instead let us treat the rapidly evolving linux landscape as a strength.

So where we are today is that I think we are very close to realizing the vision of being able to let Fedora be the place where exiting new stuff happens, yet at the same time provide the robustness and polish that end users need to be able to use it as their daily driver, it has been my daily driver for many years now and by the rapid growth of users we seen in Fedora over the last 5 years I think that is true for a lot of other people too. The goal is to allow the wider community around Linux, especially the developers, sysadmins and creators relying on Linux to do their work, to come to Fedora and interact and collaborate with the developers working on the OS itself to the benefit of all. You all are probably better judges than me to if we are succeeding with that, but I do take the increased chatter and adoption of Fedora by a lot of people doing Linux related podcasts, news sites and so on as a sign that we are succeeding. And PipeWire for me is a perfect example of how this can look, where we want to bring in the pro-audio creators to Fedora Workstation and let them interact and work closely with Wim Taymans and the PipeWire development team to make the experience even better for themselves and their fellow creators and at the same time give them a great stable platform to create their music on.

PipeWire Late Summer Update 2020

Wim Taymans

Wim Taymans talking about current state of PipeWire


Wim Taymans did an internal demonstration yesterday for the desktop team at Red Hat of the current state of PipeWire. For those still unaware PipeWire is our effort to bring together audio, video and pro-audio under Linux, creating a smooth and modern experience. Before PipeWire there was PulseAudio for consumer audio, Jack for Pro-audio and just unending pain and frustration for video. PipeWire is being done with the aim of being ABI compatible with ALSA, PulseAudio and JACK, meaning that PulseAudio and Jack apps should just keep working on top of Pipewire without the need for rewrites (and with the same low latency for JACK apps).

As Wim reported yesterday things are coming together with both the PulseAudio, Jack and ALSA backends being usable if not 100% feature complete yet. Wim has been running his system with Pipewire as the only sound server for a while now and things are now in a state where we feel ready to ask the wider community to test and help provide feedback and test cases.

Carla on PipeWire

Carla running on PipeWire

Carla as shown above is a popular Jack applications and it provides among other things this patchbay view of your audio devices and applications. I recommend you all to click in and take a close look at the screenshot above. That is the Jack application Carla running and as you see PulseAudio applications like GNOME Settings and Google Chrome are also showing up now thanks to the unified architecture of PipeWire, alongside Jack apps like Hydrogen. All of this without any changes to Carla or any of the other applications shown.

At the moment Wim is primarily testing using Cheese, GNOME Control center, Chrome, Firefox, Ardour, Carla, vlc, mplayer, totem, mpv, Catia, pavucontrol, paman, qsynth, zrythm, helm, Spotify and Calf Studio Gear. So these are the applications you should be getting the most mileage from when testing, but most others should work too.

Anyway, let me quickly go over some of the highlight from Wim’s presentation.

Session Manager

PipeWire now has a functioning session manager that allows for things like

  • Metadata, system for tagging objects with properties, visible to all clients (if permitted)
  • Load and save of volumes, automatic routing
  • Default source and sink with metadata, saved and loaded as well
  • Moving streams with metadata

Currently this is a simple sample session manager that Wim created himself, but we also have a more advanced session manager called Wireplumber being developed by Collabora, which they developed for use in automotive Linux usecases, but which we will probably be moving to over time also for the desktop.

Human readable handling of Audio Devices

Wim took the code and configuration data in Pulse Audio for ALSA Card Profiles and created a standalone library that can be shared between PipeWire and PulseAudio. This library handles ALSA sound card profiles, devices, mixers and UCM (use case manager used to configure the newer audio chips (like the Lenovo X1 Carbon) and lets PipeWire provide the correct information to provide to things like GNOME Control Center or pavucontrol. Using the same code as has been used in PulseAudio for this has the added benefit that when you switch from PulseAudio to PipeWire your devices don’t change names. So everything should look and feel just like PulseAudio from an application perspective. In fact just below is a screenshot of pavucontrol, the Pulse Audio mixer application running on top of Pipewire without a problem.

PulSe Audio Mixer

Pavucontrol, the Pulse Audio mixer on Pipewire

Creating audio sink devices with Jack
Pipewire now allows you to create new audio sink devices with Jack. So the example command below creates a Pipewire sink node out of calfjackhost and sets it up so that we can output for instance the audio from Firefox into it. At the moment you can do that by running your Jack apps like this:

PIPEWIRE_PROPS="media.class=Audio/Sink" calfjackhost

But eventually we hope to move this functionality into the GNOME Control Center or similar so that you can do this setup graphically. The screenshot below shows us using CalfJackHost as an audio sink, outputing the audio from Firefox (a PulseAudio application) and CalfJackHost generating an analyzer graph of the audio.

Calfjackhost on pipewire

The CalfJackhost being used as an audio sink for Firefox

Creating devices with GStreamer
We can also use GStreamer to create PipeWire devices now. The command belows take the popular Big Buck Bunny animation created by the great folks over at Blender and lets you set it up as a video source in PipeWire. So for instance if you always wanted to play back a video inside Cheese for instance, to apply the Cheese effects to it, you can do that this way without Cheese needing to change to handle video playback. As one can imagine this opens up the ability to string together a lot of applications in interesting ways to achieve things that there might not be an application for yet. Of course application developers can also take more direct advantage of this to easily add features to their applications, for instance I am really looking forward to something like OBS Studio taking full advantage of PipeWire.

gst-launch-1.0 uridecodebin uri=file:///home/wim/data/BigBuckBunny_320x180.mp4 ! pipewiresink mode=provide stream-properties="props,media.class=Video/Source,node.description=BBB"

Cheese paying a video through pipewire

Cheese playing a video provided by GStreamer through PipeWire.

How to get started testing PipeWire
Ok, so after seeing all of this you might be thinking, how can I test all of this stuff out and find out how my favorite applications work with PipeWire? Well first thing you should do is make sure you are running Fedora Workstation 32 or later as that is where we are developing all of this. Once you done that you need to make sure you got all the needed pieces installed:

sudo dnf install pipewire-libpulse pipewire-libjack pipewire-alsa

Once that dnf command finishes you run the following to get PulseAudio replaced by PipeWire.


cd /usr/lib64/

sudo ln -sf pipewire-0.3/pulse/libpulse-mainloop-glib.so.0 /usr/lib64/libpulse-mainloop-glib.so.0.999.0
sudo ln -sf pipewire-0.3/pulse/libpulse-simple.so.0 /usr/lib64/libpulse-simple.so.0.999.0
sudo ln -sf pipewire-0.3/pulse/libpulse.so.0 /usr/lib64/libpulse.so.0.999.0

sudo ln -sf pipewire-0.3/jack/libjack.so.0 /usr/lib64/libjack.so.0.999.0
sudo ln -sf pipewire-0.3/jack/libjacknet.so.0 /usr/lib64/libjacknet.so.0.999.0
sudo ln -sf pipewire-0.3/jack/libjackserver.so.0 /usr/lib64/libjackserver.so.0.999.0

sudo ldconfig

(you can also find those commands here

Once you run these commands you should be able to run

pactl info

and see this as the first line returned:
Server String: pipewire-0

I do recommend rebooting, to be 100% sure you are on a PipeWire system with everything outputting through PipeWire. Once that is done you are ready to start testing!

Our goal is to use the remainder of the Fedora Workstation 32 lifecycle and the Fedora Workstation 33 lifecycle to stabilize and finish the last major features of PipeWire and then start relying on it in Fedora Workstation 34. So I hope this article will encourage more people to get involved and join us on gitlab and on the PipeWire IRC channel at #pipewire on Freenode.

As we are trying to stabilize PipeWire we are working on it on a bug by bug basis atm, so if you end up testing out the current state of PipeWire then be sure to report issues back to us through the PipeWire issue tracker, but do try to ensure you have a good test case/reproducer as we are still so early in the development process that we can’t dig into ‘obscure/unreproducible’ bugs.

Also if you want/need to go back to PulseAudio you can run the commands here

Also if you just want to test a single application and not switch your whole system over you should be able to do that by using the following commands:

pw-pulse

or

pw-jack

Next Steps
So what are our exact development plans at this point? Well here is a list in somewhat priority order:

  1. Stabilize – Our top priority now is to make PipeWire so stable that the power users that we hope to attract us our first batch of users are comfortable running PipeWire as their only audio server. This is critical to build up a userbase that can help us identify and prioritize remaining issues and ensure that when we do switch Fedora Workstation over to using PipeWire as the default and only supported audio server it will be a great experience for users.
  2. Jackdbus – We want to implement support for the jackdbus API soon as we know its an important feature for the Fedora Jam folks. So we hope to get to this in the not to distant future
  3. Flatpak portal for JACK/audio applications – The future of application packaging is Flatpaks and being able to sandbox Jack applications properly inside a Flatpak is something we want to enable.
  4. Bluetooth – Bluetooth has been supported in PipeWire from the start, but as Wims focus has moved elsewhere it has gone a little stale. So we are looking at cycling back to it and cleaning it up to get it production ready. This includes proper support for things like LDAC and AAC passthrough, which is currently not handled in PulseAudio. Wim hopes to push an updated PipeWire in Fedora out next week which should at least get Bluetooth into a basic working state, but the big fix will come later.
  5. Pulse effects – Wim has looked at this, but there are some bugs that blocks data from moving through the pipeline.
  6. Latency compensation – We want complete latency compensation implemented. This is not actually in Jack currently, so it would be a net new feature.
  7. Network audio – PulseAudio style network audio is not implemented yet.

First Lenovo laptop with Fedora now available on the web!

This weekend the X1 Carbon with Fedora Workstation went live in North America on Lenovos webstore. This is a big milestone for us and for Lenovo as its the first time Fedora ships pre-installed on a laptop from a major vendor and its the first time the worlds largest laptop maker ships premium laptops with Linux directly to consumers. Currently only the X1 Carbon is available, but more models is on the way and more geographies will get added too soon. As a sidenote, the X1 Carbon and more has actually been available from Lenovo for a couple of Months now, it is just the web sales that went online now. So if you are a IT department buying Lenovo laptops in bulk, be aware that you can already buy the X1 Carbon and the P1 for instance through the direct to business sales channel.

Also as a reminder for people looking to deploy Fedora laptops or workstations in numbers, be sure to check out Fleet Commander our tool for helping you manage configurations across such a fleet.

I am very happy with the work that has been done here to get to this point both by Lenovo and from the engineers on my team here at Red Hat. For example Lenovo made sure to get all of their component makers to ramp up their Linux support and we have been working with them to both help get them started writing drivers for Linux or by helping add infrastructure they could plug their hardware into. We also worked hard to get them all set up on the Linux Vendor Firmware Service so that you could be assured to get updated firmware not just for the laptop itself, but also for its components.

We also have a list of improvements that we are working on to ensure you get the full benefit of your new laptops with Fedora and Lenovo, including working on things like improved power management features being able to have power consumption profiles that includes a high performance mode for some laptops that will allow it to run even faster when on AC power and on the other end a low power mode to maximize battery life. As part of that we are also working on adding lap detection support, so that we can ensure that you don’t risk your laptop running to hot in your lap and burning you or that radio antennas are running to strong when that close to your body.

So I hope you decide to take the leap and get one of the great developer laptops we are doing together with Lenovo. This is a unique collaboration between the worlds largest laptop maker and the worlds largest Linux company. What we are doing here isn’t just a minimal hardware enablement effort, but a concerted effort to evolve Linux as a laptop operating system and doing it in a proper open source way. So this is the culmination of our work over the last few years, creating the LVFS, adding Thunderbolt support to Linux, improving fingerprint reader support in Linux, supporting HiDPI screens, supporting hidpi mice, creating the possibility of a secure desktop with Wayland, working with NVidia to ensure that Mesa and Nvidia driver can co-exist through glvnd, creating Flatpak to ensure we can bring the advantages of containers to the desktop space and at the same way do it in a vendor neutral way. So when you buy a Lenovo laptop with Fedora Workstation, you are not just getting a great system, but you are also supporting our efforts to take Linux to the next level, something which I think we are truly the only linux vendor with the scale and engineering ability to do.

Of course we are not stopping here, so let me also use this chance to talk a bit about some of our other efforts.

Toolbox
Containers are popular for deploying software, but a lot of people are also discovering now that they are an incredible way to develop software, even if that software is not going to be deployed as a Flatpak or Kubernetes container. The term often used for containers when used as a development tool is pet containers and with Toolbox project we are aiming to create the best tool possible for developers to work with pet containers. Toolbox allows you to have always have a clean environment to work in which you can change to suit each project you work on, however you like, without affecting your host system. So for instance if you need to install a development snapshot of Python you can do that inside your Toolbox container and be confident that various other parts of your desktop will not start crashing due to the change. And when your are done with your project and don’t want that toolbox around anymore you can easily delete it without having to spend time to figure out which packages you installed can now be safely uninstalled from your host system or just not bother and have your host get bloated over time with stuff you are not actually using anymore.

One big advantage we got at Red Hat is that we are a major contributor to container technologies across the stack. We are a major participant in the Open Container Initiative and we are alongside Google the biggest contributor to the Kubernetes project. This includes having created a set of container tools called Podman. So when we started prototyping Toolbox we could base it up on podman and get access to all the power and features that podman provides, but at the same make them easier to use and consumer from your developer laptop or workstation.

Our initial motivation was also driven by the fact that for image based operating systems like Fedora Silverblue and Fedora CoreOS, where the host system is immutable you still need some way to be able to install packages and do development, but we quickly realized that the pet container development model is superior to the old ‘on host’ model even if you are using a traditional package based system like Fedora Workstation. So we started out by prototyping the baseline functionality, writing it as a shell script to quickly test out our initial ideas. Of course as Toolbox picked up in popularity we realized we needed to transition quickly to a proper development language so that we wouldn’t end up with an unmaintainable mess written in shell, and thus Debarshi Ray and Ondřej Míchal has recently completed the rewrite to Go (Note: the choice of Go was to make it easier for the wider container community to contribute since almost all container tools are written in Go).

Leading up towards Fedora Workstation 33 we are trying figure out a few things. One is how we can make giving you access to a RHEL based toolbox through the Red Hat Developer Program in an easy and straightforward manner, and this is another area where pet container development shines. You can set up your pet container to run a different Linux version than your host. So you can use Fedora to get the latest features for your laptop, but target RHEL inside your Toolbox to get an easy and quick deployment path to your company RHEL servers. I would love it if we can extend this even further as we go along, to for instance let you set up a Steam runtime toolbox to do game development targeting Steam.
Setting up a RHEL toolbox is already technically possible, but requires a lot more knowledge and understanding of the underlaying technologies than we wish.
The second thing we are looking at is how we deal with graphical applications in the context of these pet containers. The main reason we are looking at that is because while you can install for instance Visual Studio code inside the toolbox container and launch it from the command line, we realize that is not a great model for how you interact with GUI applications. At the moment the only IDE that is set up to be run in the host, but is able to interact with containers properly is GNOME Builder, but we realize that there are a lot more IDEs people are using and thus we want to try to come up with ways to make them work better with toolbox containers beyond launching them from the command line from inside the container. There are some extensions available for things like Visual Studio Code starting to try to improve things (those extensions are not created by us, but looking at solving a similar problem), but we want to see how we can help providing a polished experience here. Over time we do believe the pet container model of development is so good that most IDEs will follow in GNOME Builders footsteps and make in-container development a core part of the feature set, but for now we need to figure out a good bridging strategy.

Wayland – headless and variable refresh rate.
Since switching to Wayland we have continued to work in improving how GNOME work under Wayland to remove any major feature regressions from X11 and to start taking advantage of the opportunities that Wayland gives us. One of the last issues that Jonas Ådahl has been hard at work recently is trying to ensure we have headless support for running GNOME on systems without a screen. We know that there are a lot of sysadmins for instance who want to be able to launch a desktop session on their servers to be used as a tool to test and debug issues. These desktops are then accessed through tools such as VNC or Nice DCV. As part of that work he also made sure we could deal with having multiple monitors connected which had different refresh rates. Before that fix you would get the lowest common denominator between your screens, but now if you for instance got a 60Hz monitor and a 75Hz monitor they will be able to function independent of each other and run at their maximum refresh rate. With the variable refresh rate work now landed upstream Jonas is racing to get the headless support finished and landed in time for Fedora Workstation 33.

Linux Vendor Firmware Service
Richard Hughes is continuing his work on moving the LVFS forward having spent time this cycle working with the Linux Foundation to ensure the service can scale even better. He is also continuously onboarding new vendors and helping existing vendors use LVFS for even more things. We are now getting reports that LVFS has become so popular that we are now getting reports of major hardware companies who up to know hasn’t been to interested in the LVFS are getting told by their customers to start using it or they will switch supplier. So expect the rapid growth of vendors joining the LVFS to keep increasing. It is also worth nothing that many of vendors who are already set up on LVFS are steadily working on increasing the amount of systems they support on it and pushing their suppliers to do the same. Also for enterprise use of LVFS firmware Marc Richter also wrote an article on access.redhat.com about how to use LVFS with Red Hat Satelitte. Satellite for those who don’t know it is Red Hats tool for managing and keeping servers up to date and secure. So for large companies having their machines, especially servers, accessing LVFS directly is not a wanted behaviour, so now they can use Satelitte to provide a local repository of the LVFS firmware.

PipeWire
One of the changes we been working on that I am personally extremely excited about is PipeWire. For those of you who don’t know it, PipeWire is one of our major swamp draining efforts which aims to bring together audio, pro-audio and video under linux and provide a modern infrastructure for us to move forward. It does so however while being ABI compatible with both Jack and PulseAudio, meaning that applications will not need to be ported to work with PipeWire. We have been using it for a while for video already to handle screen capture under Wayland and for allowing Flatpak containers access to webcams in a secure way, but Wim Taymans has been working tirelessly on moving that project forward over the last 6 Months, focused a lot of fixing corner cases in the Jack support and also ramping up the PulseAudio support. We had hoped to start wide testing in Fedora Workstation 32 of the audio parts of PipeWire, but we decided that since such a key advantage that PipeWire brings is not just to replace Jack or PulseAudio, but also to ensure the two usecases co-exist and interact properly, we didn’t want to start asking people to test until we got the PulseAudio support close to being production ready. Wim has been making progress by leaps and bounds recently and while I can’t 100% promise it yet we do expect to roll out the audio bits of PipeWire for more widescale testing in Fedora Workstation 33 with the goal of making it the default for Fedora Workstation 34 or more likely Fedora Workstation 35.
Wim is doing an internal demo this week, so I will try to put out a blog post talking about that later in the week.

Flatpak – incremental updates
One of the features we added to Flatpaks was the ability to distribute them as Open Container Initiative compliant containers. The reason for this was that as companies, Red Hat included, built infrastructure for hosting and distributing containers we could also use that for Flatpaks. This is obviously a great advantage for a variety of reasons, but it had one large downside compared to the traditional way of distributing Flatpaks (as Ostree images) which is that each update comes as a single large update as opposed to the atomic update model that OStree provides.
Which is why if you would compare the same application when shipping from Flathub, which uses Ostree, versus from the Fedora container registry, you would quickly notice that you get a lot smaller updates from Flathub. For kubernetes containers this hasn’t been considered a huge problem as their main usecase is copying the containers around in a high-speed network inside your cloud provider, but for desktop users this is annoying. So Alex Larsson and Owen Taylor has been working on coming up with a way to do to incremental updates for OCI/Docker/Kubernetes containers too, which not only means we can get very close to the Flathub update size in the Fedora Container Catalog, but it also means that since we implemented this in a way that works for all OCI/Kubernetes containers you will be able to get them too with incremental update functionality. Especially as such containers are making their way into edge computing where update sizes do matter, just like they do on the desktop.

Hangul input under Wayland
Red Hat, like Lenovo, targets most of the world with our products and projects. This means that we want them to work great even for people who doesn’t use English or another European language. To achieve this we have a team dedicated to ensuring that not just Linux, but all Red Hat products work well for international users as part of my group at Red Hat. That team, lead by Jens Petersen, is distributed around the globe with engineers in Japan, China, India, Singapore and Germany. This team contributes to a lot of different things like font maintenance, input method development, i18n infrastructure and more.
One thing this team recently discovered was that the support for Korean input under Wayland. So Peng Wu, Takao Fujiwara and Carlos Garnacho worked together to come up with a series of patches for ibus and GNOME Shell to ensure that Fedora Workstation on Wayland works perfectly for Korean input. I wanted to highlight this effort because while I don’t usually mention efforts which such a regional impact in my blog posts it is a critical part of keeping Linux viable and usable across the globe. And ensuring that you can use your computer in your own language is something we feel is important and want to enable and also an area where I believe Red Hat is investing more than any other vendor out there.

GLX on EGL
We meet with NVidia on a regular basis to discuss topics of shared interest and one thing we been looking at for a while now is the best way to support Nvidia binary driver under XWayland. As part of that Adam Jackson has been working on a research project to see how feasible it would be to create a way to run GLX applications on top of EGL. As one might imagine EGL doesn’t have a 1to1 match with GLX APIs, but based on what we seen so far is that it should be close enough to get things going (Adam already got glxgears running :). The goal here would be to have an initial version that works ok, and then in collaboration with NVidia we can evolve it to be a great solution for even the most demanding OpenGL/GLX applications. Currently the code causes an extra memcopy compared to running on GLX native, but this is something we think can be resolved in collaboration with NVidia. Of course this is still an early stage effort and Adam and NVidia are currently looking at it so there is of course a chance still we will hit a snag and have to go back to the drawing board. For those interested you can take a look at this Mesa merge request to see the current state.