SMAF Still Hasn't Landed In Linux Kernel, Would Allow Better Protecting Video Playback

Last year we covered SMAF as the project aiming to allow for secure DMA-BUF usage. While that was written about nearly a year ago and had already gone through multiple patch revisions, unfortunately that code has yet to be mainlined.

A Phoronix reader wrote in this weekend to explain how he wish it would land and that it would help address an important use-case: better handling of protected video content.

Currently when rendering protected video content on the web (e.g. Chrome), a "video hole" is used to bypass the web view and render on-screen using a secured plane rather than OpenGL and thus bypasses the web engine's composition process. With video holes, there can be de-syncing issues when scrolling on a web page and other issues since it's not presented as part of the same process with all other elements on the page. With SMAF, there could be secured textures support.

Published earlier this year were the EXT_protected_textures and EGL_EXT_protected_textures extensions for OpenGL and EGL, respectively. Using these extensions together allow creating and dealing with protected contexts and resources. Making use of these by the web browsers could allow supporting protected video content without a video hole or otherwise hacking around the presentation of DRM/secure-protected videos. On Linux systems those extensions could be implemented with SMAF providing the underlying security once it's supported by the common graphics drivers.

The Phoronix reader pointed out there is work on removing VIDEO_HOLE for Chrome on Android, Android N does support secure texture video playback with supported devices/drivers, and those interested in more details on the Android 7.0 approach for secured video playback can be found via this architecture page.