sc0710

Linux driver for the Elgato 4k60 Pro Mk.2

This is a reverse engineering project. The goal is to bring support for the Elgato 4k60 card to the linux platform.

The primary development platform for the project is Centos 7.5.1804 (Core), although the driver is expected to work on multiple distributions.

License

Driver for the Elgato 4k60 Pro mk.2 HDMI capture card.

Copyright (c) 2021 Steven Toth [email protected]

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

Background

Most of the investigation work is being done on Windows 10. I'm instrumenting the hardware with debug wiring, identifying common buses, sketching out a basic hardware digram, understanding the individual components, monitoring hardware behavior and outlining a plan for the linux implementation.

The project started Early Jan 2021. One month in, early feb, I understand enough of the basic design, hardware layout, board debug points to start making an early linux driver - enough to perform signal detection of the HDMI port and do some basic hardware servicing.

All of my working notes, analyzer traces, daily journal notes will be stored in this repository - as a single source for any interested viewers.

I'm maintaining a basic 'developer journal' so interested readers can follow along. It's not my intension to do a "how to reverse engineer step-by-step" intro guide, it's really to describe the process, show some of the tooling, highlight things that worked and things that didn't work. I'm not writing an essay, its random utterances that may help another developer on a similar project.

At this stage, everything is contained in master. We don't have any branches. As the project progresses and the driver becomes usable, almost certainly, a new 'cleaner' repo will emerge and users will not be expected to download this entire repo, with huge images, analyzer traces, random notes - just to use the driver.

Status

• Jun 26 2022 - On Ubuntu, /usr/bin/pulseaudio keeps the driver open and prevents make unload during development.
• Jun 26 2022 - Forward port driver, fix broken APIs for use on Ubuntu 22.04. Basic video works on Ubuntu now.
• Jun 26 2022 - Use tag e2908371f4c2b28ea613622815dcf2b4739d3bb7 for Centos 3.10 kernels. After this we're moving to Ubuntu 5.x kernels.
• Feb 15 2021 - Detected colorimetry and colospace HDMI support.
• Feb 15 2021 - Added basic DV Timing support to expose resolution / rate material through the v4l api.
• Feb 14 2021 - Added audio support, PCM 16bit 48KHz.
• Feb 14 2021 - Driver is usable for certain resolutions for video and audio capture via ffmpeg.
• Feb 13 2021 - Overhauled the scatter gather subsystem to support 4k video.
• Feb 11 2021 - First every colorbar still iage captured via the driver.
• Aug 1 2021 - Driver adjusts to auto detect 1280x720p vs 1920x1080p and work accordingly.
• Aug 1 2021 - 4k is untested with the latest changes, but should be full supported.

TODO

• Test/Support HDR 10bit.
• Intermittent issue during capture, possible short video frame, casuses ffmpeg to error and stall.

Comments / Support

Email: [email protected]

Content

• Project root - Driver source code.
• Docs - Daily journal, random notes.
• Traces - Various dump files taken from analyzers.
• Pics - Interesting or curious pictures I've taken during the process.