[theora-dev] MMX patch to speed up Theora decoding

j at v2v.cc j at v2v.cc
Wed Mar 28 09:41:46 PDT 2007


On Mar 28, 2007, at 15:06:54, Chih-Chung Chang wrote:
> I found access to a MacBook, so here is how I build the patched  
> Theora,
> hope this works for you: (Using XCode 2.4.1)
>
> tar xzvf libtheora-1.0alpha7.tar.gz
> gzip -cd theora.patch.20070327.gz | patch -p0
> cd libtheora-1.0alpha7
> ./configure --with-ogg=/Volumes/USB/build/
> vi config.h
> # add #define USE_MMX
> vi lib/Makefile
> # add "-Wl,-read_only_relocs,suppress" just before -o in the  
> following line:
> # LINK = $(LIBTOOL) --tag=CC --mode=link $(CCLD) $(AM_CFLAGS) $ 
> (CFLAGS) \
> #	$(AM_LDFLAGS) $(LDFLAGS) -Wl,-read_only_relocs,suppress -o $@

works great now, i would still prefere to only have one way of detecting
and activating mmx code. i agree that for development its better to  
do it
inline but in terms of maintainability it is better to just have one way
of adding mmx/asm code, i put a patch that moves your code into x86_32
and adds the functions for the respective dsp calles at:

   http://people.xiph.org/~j/theora_idct_and_dctdecode_filter_mmx.patch

if there are no bigger problems with the patch,
i will commit it in the next days to svn.

j




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