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libwmapro no longer needs libm in the sim; update the makefile and README.rockbox.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@27456 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Mohamed Tarek 2010-07-17 08:19:05 +00:00
parent 86c3765246
commit 53d13a8e76
2 changed files with 6 additions and 33 deletions

View file

@ -14,27 +14,10 @@ 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.
The decoder now (17 July 2010) uses fixed point arithmetic everywhere. It still
doesn't work on 3 targets, namely clip, c200v2 and m200v4 due to their small
codec buffer compared to wma pro's needs.
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
A comparison against ffmpeg floating point decoder gives :
0.2~0.3% max relative error
0.005~0.01% average relative error

View file

@ -16,13 +16,3 @@ OTHER_SRC += $(WMAPROLIB_SRC)
$(WMAPROLIB): $(WMAPROLIB_OBJ)
$(SILENT)$(shell rm -f $@)
$(call PRINTS,AR $(@F))$(AR) rcs $@ $^ >/dev/null
ifdef APP_TYPE
# wmapro needs libm in the simulator
$(CODECDIR)/wmapro.codec: $(CODECDIR)/wmapro.o
$(call PRINTS,LD $(@F))$(CC) $(CODECFLAGS) -o $(CODECDIR)/wmapro.elf \
$(filter %.o, $^) \
$(filter %.a, $+) \
-lgcc -lm $(CODECLDFLAGS)
$(SILENT)cp $(CODECDIR)/wmapro.elf $@
endif