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Old 26th April 2007, 13:44   #34  |  Link
plugh
A hollow voice says
 
Join Date: Sep 2006
Posts: 269
So that three line change *can* be considered a "fix" for 1.1.2?

Given I'm only working with "HD" encodes (and with 4mv off), perhaps that magnitude of vector is somewhat more likely? ie MB displacement across X% of the image literally crosses more pixels? (Don't know what I'm talking about, but it sounds good anyway )

BTW, there was one other thing in the huge volume of debug print data I collected that struck me - I'll pass it on, for whatever it is worth.

In ModeDecisionBVOP_RD, right after the "evaluate cost of all modes" loop, the values for d_rd, f_rd, b_rd, i_rd were frequently the same (with my short test clip). The code is evaluating the modes in increasing SAD order, but in this case should it simply choose the 'first' mode at that cost?

EDIT: Duh - stupid question; you want the one with the lowest SAD. never mind...

Anyway, it happens enough (multiple modes yeilding same rd) in my data that it caught my eye, so I thought I'd mention it. Seemed odd, given radically differant code paths.

Examples: - Frame 182, the 4 SADs, evaluation order stuff, x/y of MB, the four RD costs, the chosen cost/mode

182 ds=464 bs=301 fs=464 is=238 bst=238 order=1 2 0 3 num=4 I0 B1 D2 F3 x=41 y=0 d=770 f=786 b=770 i=770 rd=770 mod=1
182 ds=324 bs=306 fs=340 is=216 bst=216 order=1 2 0 3 num=4 I0 B1 D2 F3 x=22 y=1 d=1179 f=1195 b=1179 i=1179 rd=1179 mod=1

Last edited by plugh; 26th April 2007 at 15:58.
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