Mentorship Session: Testing the Media Subsystem: Compliance Tests and Virtual Drivers
Channel: The Linux Foundation
Date: 2023-04-19

Mentor: Hans Verkuil, Senior Software Engineer R&D, Cisco Systems Norway

The media APIs are very large in order to cope with the vast array of different media hardware: anything from webcams, analog and/or digital TV capture, complex SoC image processing pipelines, hardware codecs, to simple FM Radio Receivers.

That makes testing very difficult since the number of test combinations can be almost infinite. Not only that, but a lot of the media hardware is hard or impossible to get. This also makes regression testing difficult after making changes to the media core since how do you test it without access to hardware?

This presentation describes how we (for the most part) solved this issue by creating compliance test utilities together with media drivers that emulate media hardware ('virtual drivers').