Hi, > > I wrote a vertical chrominance filter (*) for the XVideo module using > > inline MMX assembly. This allows me to improve output quality without > > any speed penalty. > > Do you mean for upsampling to 4:2:2 ? How do you filter? Do you > average to create the new chroma line?
Something like that, the filter uses 0.75x nearest chrominance sample and 0.25x second nearest chrominance sample. This is more accurate as it doesn't shift the chrominance signal by 1 pixel. Here are the patches, the second one is for enabling the horizontal filtering in hardware: http://rambo.its.tudelft.nl/~ewald/XFree86-4.1.99.4-mga-xv-mmx-chromafilter.patch http://rambo.its.tudelft.nl/~ewald/XFree86-4.2.0-mga-xv-uvfilter.patch These are not paired for Pentium MMX, but performance is already better than the C version (which compiles to slow "movzx" instructions). It's nearly optimal for AMD Athlon though (about 2 IPC using L1-cache). bye, ewald _______________________________________________ Xpert mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/xpert
