Hans Verkuil

In the past year 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 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.

The past year the focus in this kernel subsystem was on bug fixing, new drivers and improved CEC debugging support. This presentation gives an overview of the current status and future work.

This talk is a replacement for the cancelled talk by intel's Manasi Navare "Display Stream Compression: More pixels, faster, over DisplayPort", as intel decided not to approve travel for Manasi.

The HDMI connector features a CEC (Consumer Electronics Control) pin that allows connected devices to detect and control one another. This talk describes what CEC is, why you would want to implement support for it, and how you can use a new kernel framework and API to support this HDMI feature.

The video4linux kernel subsystem reports which colorspace the captured video uses. But what does that really mean, and what do you have to do to correctly reproduce those colors? This talk will dive into the crazy world of colorspaces and give you a practical guide to colorspace handling. I will also demonstrate colorspace handling, both right and wrong.

The video4linux subsystem of the kernel is a very large API with many ioctls, settings, options and capabilities. This poses a problem both for the kernel developer and for the application developer. Since early 2014 major improvements have been made to both the v4l2-compliance utility for verifying drivers, and to the virtual video driver that applications can use as a reference input. This presentation will explain and demonstrate this utility and driver and show how to use them to ensure your driver or application works correctly.

During the past five years a lot of work went into the video4linux subsystem of the kernel, in particular with respect to the frameworks that help the driver developers. This talk gives an overview of the kernel frameworks that help video4linux driver developers create good drivers.

Writing video capture or codec drivers used to be quite complex, but these days there are several frameworks available in the video4linux subsystem that take care of a lot of the common problems that all drivers have to solve, allowing the developer to concentrate on the actual code that controls the hardware.

This presentation examines how modern V4L drivers are written and which frameworks are available to help you write good driver code in less time.