Re: H.264 codec and optimization issues

    I believe that the lesson that should be learned from this paper it's that the way
to optimization comes first from doing detailed profiling to see where the performance
penalties come from.  Real life experience is full of cases of huge blind optimization
efforts that at the end result in to significant speed-ups because the bottleneck was
not there.

    Another lesson is that in H.264 ( and in all codecs in general), the performance
hot-spots are located in a few "kernels" ( like transform, SAD, VLC...).  In this
aspect, the eventual performance penalties deriving from a "clean" implementation
will not impact performance in any significant way, since the bottlenecks will lie
into those kernels.

----- Original Message ----- 
  From: Indrajit Chakrabarty 
  To: [email protected] 
  Sent: Monday, March 31, 2003 10:54 AM
  Subject: [Hdot264-devel] H.264 codec and optimization issues


  Dear All

  Please have a look at the following paper "Implementation of H.264 decoder on general-purpose processors with media instructions" which is available at

  http://www.ee.princeton.edu/~ykchen/publications/H264.html

  This paper talks about several modules in the JVT codec and there is an interesting discussion about the implementation and optimization of the inverse transform using shifts and adds only. In the end, for an SSE/SSE2 or even MMX implementation, using shifts and adds may not be very optimal!

   

  Cheers,
  Indrajit

   





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