Allwinner VPU support in mainline Linux status update (week 15)

This week, Paul worked on preparing a new version of the patch series introducing support for the Sunxi-Cedrus VPU kernel driver, based upon the latest version of the Request API as submitted for review by Hans Verkuil on Monday. In order to make it easier to test the kernel driver, a standalone tool was written to decode a single frame (that was dumped beforehand). Support for displaying the decoded frame directly into a DRM plane was also added later this week, providing direct visual feedback. Finally, significant work was put into our libVA backend, that saw a significant rewrite of the memory-management logic related to video buffers.

We plan to prepare and release this new standalone tool as well as the libVA improvements when the kernel driver patch series is ready for submission, sometime next week. Specific instructions to get this up and running will also be made available on the Sunxi-Cedrus page of the linux-sunxi wiki, for one of the supported platforms. So far, we have tested the series on A33 and A20, but it is very likely that A10 and A13 will work just as well.

On his side, Maxime continued his effort on the H264 decoding. He first looked at the Chrome OS kernel and userspace code to drive the Rockchip SoCs VPU. This code is of interest because it’s basically the only stack so far that is functional, used and based on the Request API since Google is especially involved in the development of that API. He then went on with mapping the request API controls for H264 to the code for H264 decoding in the libvdpau-sunxi code that already provides an implementation for the Allwinner VPU. He then started to write some kernel code to add support for the kernel part of the API.

Author: Paul Kocialkowski

Paul is a kernel and embedded Linux intern at Bootlin. You can find more details about Paul on his personal website: http://www.paulk.fr/

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