Integrating Hardware-accelerated Video Decoding with the Display Stack - Paul Kocialkowski, Bootlin

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.