CedarX is a proprietary multimedia framework distributed by Allwinner and not supported by the linux-sunxi community.
- It's the name of the proprietary software libraries responsible for hardware accelerated video and audio de-/encoding (CedarV + CedarA) in conjunction with with a hardware block. As for audio, the hardware ACE (Audio Codec Engine) appears to only exist in A10 and older SoCs. Allwinner refactored their proprietary userspace libraries and published them partly under GPLv2 naming them "media-codec" while some codecs are still only available as proprietary binary blobs linked in like plugins.
After some pressure caused by the controversies     surrounding the license of this library, Allwinner released a new media-codec library called Sunxi-CedarX  , which is a rewrite that up to now only partial implements some codecs as open source, letting the rest of the codecs and features such an encoding dependents of a closed source plugin binary.
Disadvantages Allwinner's CedarX technology and libraries:
- Allwinner's own CedarX proprietary libraries are known to have no clear usage license, so even if the source code for some versions is available the terms-of-use is unknown in open source software. Allwinner is slowly working towards to resolve this issue.
The video engine was and is currently being reverse engineered with successful results. To the point of making possible an experimental vdpau implementation capable of being used to play videos.
- Reverse engineering progress history
- Video Engine (VE) VE Register guide
- Audio Codec Engine (ACE) ACE Register guide
- The page of this effort entitled Cedrus Project.
CedarX official source code libraries and third-party forks
- https://github.com/allwinner-zh/media-codec Officiall Allwinner source tree
- https://github.com/fsebentley/CedarX-12.06.2015 This is new source and binary plugins from Allwinner with some API documentation and example C application...
The following are old and obsolete, is not recommend for any use.
- https://github.com/allwinner-dev-team/android_external_cedarx Allwinner Dev Team Android external CedarX fork
- https://github.com/linux-sunxi/cedarx-libs linux-sunxi team fork of the official Allwinner CedarX libcedar source code libraries
- https://github.com/huceke/libcedar libcedar decoder library for libvecore by Edgar Hucek (a.k.a. Gimli) fork for outdated XBMC
- https://github.com/willswang/libcedarx Wills Wang libcedarx library for libvecore fork for VLC
- https://github.com/mortaromarcello/android_external_cedarx Android external CedarX fork by mortaromarcello
Possibly irrelevant observations
- There seems to be a distinction in the Android code between audio decoding ("CedarA") and video decoding ("CedarV").
- CedarX/Misc Docs - some useful facts from IRC chat conversations
- CedarXVideoRenderingChart - Overview chart of working/ non working video files
- CedarX/libve - Using the Android blob on linux via libhybris
- XBMC (outdated) - XBMC Media Center
- VLC - VideoLAN Client
- CedarXPlayerTest - Testing player from Ubuntu image