Another ARM Video Decoder Being Reverse-Engineered

Written by Michael Larabel in Arm on 4 September 2012 at 09:45 AM EDT. 6 Comments
ARM
While the binary wall has yet to fall with ARM SoC vendors in terms of providing open-source drivers -- namely when it comes to the graphics / multimedia blocks -- there's many active community projects for reverse-engineering these ARM blocks to provide open-source support. Here's another project that's being done for cracking the video decoder on a popular Chinese ARM SoC.

Many of the open-source ARM graphics initiatives (either officially supported by the vendor or the community) are documented in this Phoronix article while yesterday I exclusively detailed another project that's cracking Broadcom's VideoCore with an open-source driver. Another less heard of initiative is reverse-engineering and writing an open-source library to support the video decoder on the Allwinner A10.

The Allwinner A10 is the popular SoC out of China that's a 1.2GHz ARM Cortex-A8 with Mali-400 graphics processor. It's nothing special from a hardware perspective compared to modern ARM SoCs, but what makes it attractive is the price-point, which is just a few dollars (circa $7 per SoC). Due to the low price point, the Allwinner A10 has become popular for low-end tablets, namely those out of the Asian vendors.

The Allwinner SoC is capable of HD video decoding with all major formats like H.264 MVC, VC-1, MPEG-2, and MPEG-4. There's also H.264 encoding support.

Allwinner implements the video decoding support for Linux within a closed libcedarxalloc.a library, but that's being reverse-engineered and re-implemented as open-source. This library is used for managing memory allocated to the "cedarx" video decoder on the A10, which is a step towards reverse-engineering the entire decoder chip.

The project re-implementing this library as open-source is called open_cdxalloc and is being hosted on GitHub. The project began in mid-June per the original announcement. Unfortunately though there hasn't been many commits to this open-source library as of late.
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Michael Larabel

Michael Larabel is the principal author of Phoronix.com and founded the site in 2004 with a focus on enriching the Linux hardware experience. Michael has written more than 20,000 articles covering the state of Linux hardware support, Linux performance, graphics drivers, and other topics. Michael is also the lead developer of the Phoronix Test Suite, Phoromatic, and OpenBenchmarking.org automated benchmarking software. He can be followed via Twitter, LinkedIn, or contacted via MichaelLarabel.com.

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