using an 8-tap filter.
The results with 3 different 8-tap filters on the derf set are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp.html
The one that gives the most gain achieves an overall gain of about
0.6%. The results for a set of 12 hd (720p) videos are in:
http://www.corp.google.com/~debargha/vp8_results/enhinterp_hd.html
with max gain of 0.55% with the same filter. The best filter apparently
achieves the best trade-off between pass band ripple and stop band
attenuation.
Change-Id: I919e28ae245c0493147fa0864f8c9d048a9dd530
make reference version of bilinear_filters short.
use reference versions of bilinear_filters and sub_pel_filters when
possible.
recognize that Width was being passed into
filter_block2d_bil_first_pass multiple times. ARM version had already
fixed this. propegate to C.
change references to src_pixels_per_line to src_pitch and standardize on
src/dst (instead of input/output).
recognize that first_pass is only run in the verticle and second_pass
only horizontal. ARM version had already fixed this. propegate to C
Change-Id: I292d376d239a9a7ca37ec2bf03cc0720606983e2