rockbox/lib/rbcodec/codecs/libcook/README.rockbox
Sean Bartell f40bfc9267 Add codecs to librbcodec.
Change-Id: Id7f4717d51ed02d67cb9f9cb3c0ada4a81843f97
Reviewed-on: http://gerrit.rockbox.org/137
Reviewed-by: Nils Wallménius <nils@rockbox.org>
Tested-by: Nils Wallménius <nils@rockbox.org>
2012-04-25 22:13:20 +02:00

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Library: libcook
Imported by : Mohamed Tarek
These files comprise a rm parser and a cook decoder based on the decoder
from ffmpeg.
LICENSING INFORMATION
ffmpeg is licensed under the Lesser GNU General Public License and the
file cook.c is Copyright 2003 Sascha Sommer and 2005 Benjamin Larsson.
IMPORT DETAILS
The decoder is based on ffmpeg-svn r18079.
CONVERSION TO FIXED-POINT
A patch from ffmpeg's mailing list was used to convert the decoder to
use fixed-point arithmetic. The patch was done by Ian Braithwaite, and
discussed here :
http://thread.gmane.org/gmane.comp.video.ffmpeg.devel/46024
The patch is a bit dated (2007) so the modifications to cook.c had to
be done manually. The patch was also applied to cookdata.h and was
used to create cookdata_fixpoint.h, cook_fixpoint.h and
cook_fixp_mdct.h.
cook_fixp_mdct.h and parts from cookdata_fixpoint.h were dropped and
rockbox's mdct library is now used in both the test program and the
real codec.
Note : Only parts of the patch were committed to ffmpeg's repository.
TESTING
The test program should compile in any Unix-like environment using the
command "make -f Makefile.test".
For ARM targets add -DCPU_ARM to CFLAGS in Makefile.test to make use of
the asm ARM optimisations in rockbox's mdct library.
For Big-endian targets, change -D"ROCKBOX_LITTLE_ENDIAN=1"
to -D"ROCKBOX_BIG_ENDIAN=1" in Makefile.test.
Running "./cooktest file.rm" will decode the audio data to a WAV file
called "output.wav" in the current directory.