[XviD-devel] sse2

peter ross xvid-devel@xvid.org
Thu, 25 Jul 2002 17:58:23 +1000


i've just ran some xvid sse2 tests. most functions seems to work. there 
doesnt seem to much speed improvement over mmx/xmm.

notes:
- someone has wrote newer sad16_sse2 and dev16_sse2 function which perform 
unalignment checks. these funcs appear much slower than dan's old functions. 
who wrote this code??

btw, the new dev16_sse2 is not functionally equivalent to dev16_c

- fdct_sse2 is also not functionally equivalent to fdct_mmx (less accurate) 
...and causes the bitstream to increase in size: an extra 100kb for a 24meg 
avi.  fdct_sse2 is about 90% faster than the mmx version.

is anyone using a p4, and can confirm the above? i'd like to enable the sse2 
optimizations for public use, as they're currently #def'd out.

-- pete


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