October 31 - November 1 - Co-Located Events
October 28-30 - Conference
Lyon Convention Centre - Lyon, France
More information for Open Source Summit + Embedded Linux Conference Europe 2019

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Embedded Linux Conference [clear filter]
Monday, October 28


V4L2: A Status Update - Hans Verkuil, Cisco Systems Norway
Since the beginning of 2018 a lot of work has been put into improving the V4L2 subsystem. The main addition was the Request API, which is required for stateless hardware codecs, and will help improve complex camera pipelines. Codecs in general saw a lot of attention and our virtual drivers (such as the new vicodec driver) are now being used in test frameworks. So it is time to present an overview of the current state of V4L2 and what can be expected from it in the future.


Hans Verkuil

Sr. R&D Software Engineer, Cisco Systems Norway
Hans Verkuil started contributing patches to the MPEG encoder/decoder ivtv driver in early 2004 and it snowballed from there. Since 2013 he is a video4linux co-maintainer responsible for V4L2 bridge drivers and video receivers and transmitters. Since 2016, he also maintains the HDMI... Read More →

Monday October 28, 2019 11:30 - 12:05
Forum 1
  • Session Slides Included Yes
Tuesday, October 29


Integrating Hardware-accelerated Video Decoding with the Display Stack - Paul Kocialkowski, Bootlin
In February 2018, Bootlin launched a crowdfunding campaign to fund the
development of upstream Linux kernel support for the hardware-accelerated
video decoder (VPU) found on Allwinner platforms. This work is part of
Bootlin's larger ongoing effort to provide upstream Linux support for
these platforms.

Adding support for the VPU itself was a significant effort, involving a
whole new V4L2 API (the Request API) used on top of the existing M2M API,
codec-specific uAPI bits, a new driver (cedrus) as well as userspace
components such as a VAAPI backend and a test utility. However, the most
painful point turned out to be the integration of the decoded frames with
the various possible display pipelines.

This talk will introduce some context about hardware video decoding,
the work we carried out and the major issue we encountered with display
integration as well as lessons learned from the experience.


Paul Kocialkowski

Embedded Linux engineer, Bootlin
Paul joined Bootlin in 2018 and started with bringing support for the Allwinner VPU driver to mainline Linux. He went on to cover more topics related to graphics and multimedia, with various contributions to the DRM Linux subsystem and related projects. Before that, Paul worked on... Read More →

Tuesday October 29, 2019 14:25 - 15:00
Forum 2
  • Session Slides Included Yes
Wednesday, October 30


Supporting Video (de)serializers in Linux: Challenges and Works in Progress - Luca Ceresoli, AIM Sportline
Video serializer and deserializer chipsets are more and more used in embedded Linux systems to transmit raw video at several meters distance. Yet the kernel still lacks support for them, despite the attempts seen so far.

Luca will give an overview of the existing chips and the current mainlining attempts. He will then introduce the peculiar requirements of his application and the idea behind his implementation effort.

Special attention will be given to the current limitations of V4L2 and Device Tree that prevent to fully exploit the hotplug features of the chips, and how they influenced his implementation.

The I2C address translation available in some chips, and how to model it in the kernel, will also be covered.

avatar for Luca Ceresoli

Luca Ceresoli

Embedded Linux Engineer, AIM Sportline
Luca Ceresoli is an Embedded Linux Engineer at AIM Sportline. He designed several embedded Linux products from the ground up, mostly hacking around kernel, device drivers, bootloader, system programming, build system and FPGA.He contributes to a few open-source projects, including... Read More →

Wednesday October 30, 2019 12:20 - 12:55
Forum 2
  • Session Slides Included Yes