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| author | Yaowu Xu <yaowu@google.com> | 2011-10-12 10:49:49 -0700 |
|---|---|---|
| committer | Yaowu Xu <yaowu@google.com> | 2011-10-14 09:33:54 -0700 |
| commit | 152ce6b2b901279d1154ef45e8b387eb23cad3a0 (patch) | |
| tree | e1286b731c1b69f25c842bdb93b3496a8090bc96 /vp8/encoder/rdopt.c | |
| parent | 3ca849691cf09d4b4e0561f334e9a4247cc9f06a (diff) | |
| download | libvpx-152ce6b2b901279d1154ef45e8b387eb23cad3a0.tar libvpx-152ce6b2b901279d1154ef45e8b387eb23cad3a0.tar.gz libvpx-152ce6b2b901279d1154ef45e8b387eb23cad3a0.tar.bz2 libvpx-152ce6b2b901279d1154ef45e8b387eb23cad3a0.zip | |
fixed the wrong rounding in inverse haar transform
Given the current forward haar transform:
f0 = I0 + I1 + I2 + I3
f1 = I0 + I1 - I2 - I3
f2 = I0 - I1 + I2 - I3
f3 = I0 - I1 - I2 + I3
the output of the inverse haar prior rounding:
i0 = f0 + f1 + f2 + f3 = I0 * 4;
i1 = f0 + f1 - f2 - f3 = I1 * 4;
i2 = f0 - f1 + f2 - f3 = I2 * 4;
i3 = f0 - f1 - f2 + f3 = I3 * 4;
As all the numbers are 4 multiples, simply >>2 always produces prefect
results in term of forward-inverse transform round trip error.
Change-Id: Id6658b00ea819ee61cfeef8c5985d4cd3e77f44e
Diffstat (limited to 'vp8/encoder/rdopt.c')
0 files changed, 0 insertions, 0 deletions