[MacPorts] #19314: ffmpeg: enable mmx optimizations by default

[MacPorts]

#19314: ffmpeg: enable mmx optimizations by default
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 Reporter:  devans@…             |       Owner:  devans@…           
     Type:  defect               |      Status:  assigned           
 Priority:  Normal               |   Milestone:  Port Bugs          
Component:  ports                |     Version:  1.7.1              
 Keywords:  mmx Intel            |        Port:  ffmpeg             
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Comment(by devans@…):

 Yes, I agree. I was just trying to get people to upgrade to the latest on
 general principal and you caught me! ;-)

 In addition are these issues which I previously glossed over

   * technically --disable-mmx only addresses a subset of Intel-like
 optimizations.  The full set of configure options are
 {{{
   --disable-amd3dnow       disable 3DNow! optimizations
   --disable-amd3dnowext    disable 3DNow! extended optimizations
   --disable-mmx            disable MMX optimizations
   --disable-mmx2           disable MMX2 optimizations
   --disable-sse            disable SSE optimizations
   --disable-ssse3          disable SSSE3 optimizations
 }}}


   * the --disable-mmx configure option for ffmpeg is not completely
 effective in the current release 0.5 or on svn trunk (ffmpeg-devel.)  The
 ifdef logic in libswscale/rgb2rgb.c keys on the definition of ARCH_X86
 only and ignores and even overwrites HAVE_MMX, HAVE_MMX2, etc that result
 from the configure options.  The resulting behavior is to compile separate
 versions of the accelerated functions for each possible combination of
 acceleration options.  The correct optimization function is then selected
 based on a check at run time.  Thus, at least in this one instance, there
 is no protection from the XCode 3.0 gcc compilation bug.

-- 
Ticket URL: <http://trac.macports.org/ticket/19314#comment:6>
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