From fc28cb4ed5adf4a0bc548af38ca6de95bbf027e5 Mon Sep 17 00:00:00 2001 From: Dave Chapman Date: Sun, 10 May 2009 22:26:02 +0000 Subject: Patch by Mohamed Tarek from FS#10182 - convert codec to fixed-point using patches submitted to the ffmpeg mailing list in 2007 by Ian Braithwaite. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20901 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libcook/README.rockbox | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'apps/codecs/libcook/README.rockbox') diff --git a/apps/codecs/libcook/README.rockbox b/apps/codecs/libcook/README.rockbox index 9447b96be5..b51508f8a9 100644 --- a/apps/codecs/libcook/README.rockbox +++ b/apps/codecs/libcook/README.rockbox @@ -31,6 +31,24 @@ compile cook.c and the related files outside ffmpeg. The decoder still uses floating point and relies on dynamic allocations in some parts of it. It's still not ready to be ported to rockbox. +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. + +The patch used a cook_random() function for noise filling. this was +dropped and av_lfg_get() was used instead for consistency. + +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 -- cgit v1.2.3