In the variance calculations the difference is summed and later squared.
When the sum exceeds sqrt(2^31) the value is treated as a negative when
it is shifted which gives incorrect results.
To fix this we force the multiplication to be unsigned.
The alternative fix is to shift sum down by 4 before multiplying.
However that will reduce precision.
For 16x16 blocks the maximum sum is 65280 and sqrt(2^31) is 46340 (and
change).
This change is based on:
1698234 Missed some variance casts
fea3556 Fix variance overflow
Change-Id: I2c61856cca9db54b9b81de83b4505ea81a050a0f
s/([vV][pP])8/$19/
additionally dct.h was removed; declare the _c functions that are used
in the tests. the TODO for conversion to parameterized tests still
remains.
Change-Id: I73db9425a57075bbb78a92693ba6b320578981cd
The transform functions in experimental branch absorbed a scaling
factor of 4 to allow quantization steps closer to unit quantizer.
This commit added scaling code in between forward and inverse
transform to properly account for the scaling factor.
Change-Id: I9a573ddc1ffa74973b34800a5da1a56dbabe0949
The commit replaces run-time initialization of cosine constants with
static constant values, which provides ~30% relief on slow speed. The
real solution, however will be to implement integer versions of those
functions that current use float/double.
Change-Id: Ie3ff1793509653d78dd1aeaf88cc6737da1bc55f
Set on all 16x16 intra/inter modes
Features:
- Butterfly fDCT/iDCT
- Loop filter does not filter internal edges with 16x16
- Optimize coefficient function
- Update coefficient probability function
- RD
- Entropy stats
- 16x16 is a config option
Have not tested with experiments.
hd: 2.60%
std-hd: 2.43%
yt: 1.32%
derf: 0.60%
Change-Id: I96fb090517c30c5da84bad4fae602c3ec0c58b1c
