rockbox/apps/codecs/libwmapro/README.rockbox

Library: libwmapro
Imported: 2010-04-30 by Mohamed Tarek

This set of files form the files needed from ffmpeg's libavcodec and libavutil
to build a standalone wma professional decoder.

LICENSING INFORMATION

ffmpeg is licensed under the Lesser GNU General Public License and the file
wmaprodec.c is copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
and copyright (c) 2008 - 2009 Sascha Sommer, Benjamin Larsson.

IMPORT DETAILS

Based on ffmpeg svn r22886 dated 15 April 2010.

The code is slowly being modified to convert it from floating point maths to 
fixed point.

As of 6 July 2010, the following steps are all working properly in fixed point:
- Inverse quantization and rescaling
- IMDCT
- Windowing

Results of comparing output wav files from the partially fixed point decoder to 
the output wav files of ffmpeg decoder are :
- average relative error = 0.016%
- maximum relative error = 0.3% 

COMPILING

At the time of this writing (21 June 2010) the decoder isn't still included in
the main build since it still only works in the simulator.

A patch is included that would enable building the library and the codec for
testing and development purposes.

To apply the patch, you should cd to libwmapro directory and then execute the 
following command :
patch -p 0 < wmapro_mainbuild.patch