We've got a BP for this: https://blueprints.launchpad.net/linaro-android/+spec/linaro-android-try-libjpeg-turbo
On 23 June 2011 03:30, Alexander Sack <a...@linaro.org> wrote: > On Thu, Jun 23, 2011 at 3:30 AM, Christian Robottom Reis > <k...@linaro.org> wrote: >> Hi there, >> >> I took a look at the AOSP libjpeg code which is included in >> >> git://android.git.kernel.org/platform/external/jpeg >> >> during my flight back home (which incidentally had been diverted and >> landed me in Rio de Janeiro; not sure if I celebrate or cry) and noted >> the following things: >> >> - There is a v6 implementation of the fast IDCT algorithm which >> lives in armv6_idct.S. >> >> - The commit which adds this implementation was added October 2010, >> and there haven't been any changes since. >> >> - The code that selects the decoder IDCT implementation in >> jddctmgr.c always uses that implementation if ANDROID_ARMV6_IDCT >> is defined. >> >> - Google have an "ashmem" backing store implementation, and have >> code to enable tile-based mode. It's a fairly non-intrusive change >> to use ashmem since it just replaces jpeg_open_backing_store. >> >> - The code is pretty much standard libjpeg without any structural >> changes to it. >> >> - There isn't any NEON code in this branch. >> >> - Mans has an optimized version here: >> >> http://git.mansr.com/?p=libjpeg;a=summary >> >> I don't know if he's submitted this to AOSP or not. >> >> This suggests to me that a simple drop-in of libjpeg-turbo might be >> actually easy to do, and that there is probably a significant >> performance benefit to be achieved. One thing to keep in mind is that >> this code still supports armv6, so we'd probably want to preserve that. > > sounds good. Seems like a great starter project for MM WG to get their > hands dirty on android. > > They could have three builds: > > 1. plain LEB > 2. LEB with mans optimized libjpeg > 3. LEB with libjpeg-turbo > > Then benchmark all three and keep AOSP community posted on our intent, > progress and results. > > -- > > - Alexander > _______________________________________________ linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
