Summer updates
Somehow I internalized that my duty as software programmer was to silently work in a piece of code as if it were a magnum opus, until it’s finished, and then release it to the world with no need of explanations, because it should speak for itself. In other words, I tend to consider my work as a form of art, and myself as an artist. But I’m not. There’s no magnus opus and there will never be one. I’m rather a craftsman, in the sense of Richard Sennett: somebody who cares about their craft, making small, quick but thoughtful and clean changes, here and there, hoping that they will be useful to someone, now and in the future. And those little efforts need to be exposed openly, in spaces as this one and social media, as if I were a bazaar merchant.
This reflection invites me to add another task to my duties as software programmer: a periodical exposition of the work done. And this is the first intent to forge a (monthly) discipline in that direction, not in the sense of bragging, or looking to overprice a product (in the sense of commodity fetishism), but to build bridges with those that might find useful those pieces of software.
Let’s start.
GStreamer YUV4MPEG2 encoder and decoder #
We have been working lately on video encoding, and we wanted an easy way to test
our work, using common samples such as those shared by the Derf’s
collection. They are in a file format known
as YUV4MPEG2, or more commonly known as y4m, because of their file name
extension.
YUV4MPEG2 is a simple file format designed to hold uncompressed frames of YUV video, formatted as YCbCr 4:2:0, YCbCr 4:2:2 or YCbCr 4:4:4 data for the purpose of encoding. Instead of using raw YUV streams, where the frame size and color format have to be provided out-of-band, these metadata are embedded in the file.
There were already GStreamer elements for encoding and decoding y4m streams,
but y4mdec was in gst-plugins-bad while y4menc in gst-plugins-good.
Our first task was to fix and improve y4menc
[!8654],
then move y4mdec to gst-plugins-good
[!8719],
but that implied to rewrite the element and add unit tests, while add more
features such as handling more color formats.
Soothe — video encoders testing framework #
Heavily inspired by Fluster, a testing framework written in Python for decoder conformance, we are sketching Soothe, a script that aims to be a testing framework for video encoders, using VMAF, a perceptual video quality assessment algorithm.
GStreamer Vulkan H.264 encoder #
This is the reason of the efforts expressed above: vulkanh264enc, a H.264
encoder using the Vulkan Video extension
[!7197].
One interesting side of this task was to propose a base class for hardware
accelerated H.264 encoders, based on the vah264enc, the GStreamer VA-API H.264
encoder. We talked about this base class in the GStreamer Conference
2024.
Now the H.264 encoder merged and it will be part of the future release of GStreamer 1.28.
Removal of GStreamer-VAAPI subproject #
We’re very grateful with GStreamer-VAAPI. When its maintenance were handed over to us, after a few months we got the privilege to merge it as an official GStreamer subproject.
Now GStreamer-VAAPI functionality has been replaced with the VA plugin in gst-plugins-bad. Still, it isn’t a full featured replacement [#3947], but it’s complete and stable enough to be widely deployed. As Tim said in the GStreamer Conference 2024: it just works.
So, GStreamer-VAAPI subproject has been removed from main branch in git repository [!9200], and its Gitlab project, archived.
Vulkan Video Status page #
We believe that Vulkan Video extension will be one of the main APIs for video encoding, decoding and processing. Igalia participate in the Vulkan Video Technical Sub Group (TSG) and helps with the Conformance Test Suite (CTS).
Vulkan Video extension is big and constantly updated. In order to keep track of it we maintain a web page with the latest news about the specification, proprietary drivers, open source drivers and open source applications, along with articles and talks about it.
https://vulkan-video-status.igalia.com
GStreamer Planet #
Last but not least, GStreamer Planet has been updated and overhauled.
Given that the old Planet script, written in Python 2, is unmaintained, we worked on a new one in Rust: planet-rs. It internally uses tera for templates, feed-rs for feed parsing, and reqwest for HTTP handling. The planet is generated using Gitlab scheduled CI pipelines.
https://gstreamer.freedesktop.org/planet
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