Open Source Summit + Embedded Linux Conference + OSPOCon 2021

Over the last year, work on the Linux kernel's Video4Linux2 API has brought stateless decoding support for both VP8 and H.264. But what about High Efficiency Video Coding (HEVC), also known as H.265? Efforts around VeriSilicon's Hantro Codec, a stateless accelerator present in a number of popular SoCs such as Rockchip, i.MX8, and Microchip, have resulted in HEVC/H.265 support being introduced earlier this year on NXP's i.MX 8M chipset. While this was an exciting milestone, and a step in the right direction, much work still remains. Unlike the currently supported codecs (JPEG, MPEG-2, VP8 and H.264), HEVC doesn't rely on the G1 hardware block but on the second video processor unit: the G2. Supporting HEVC on the Hantro driver has helped mature the HEVC V4L2 stateless API, however there are still many challenges before being able to declare this API as stable. Getting HEVC as a stable API is an important requirement for the userspace stacks that are relying on it. In this talk, we'll an overview of recent work around stateless codecs and request APIs, dive into HEVC/H.265 and the challenges faced, and discuss the way forward to become a stable API.