Calculate the difference variance between last source frame and
current source frame. The variance is calculated at 16x16 block
level. The variances are compared to several thresholds to decide
final partition sizes.
An adaptive strategy is implemented to decide using
SOURCE_VAR_BASED_PARTITION or FIXED_PARTITION based on motions
in the video. The switching test is done once every
search_type_check_frequency frames.
The selection of source_var_thresh needs to be investigated
further later.
RTC set Borg test showed 0.424% overall psnr gain, and 0.357%
ssim gain. For clips with large enough static area, the
encoding speedup is around 2% to 15%.
Change-Id: Id7d268f1d8cbca7fb8026aa4a53b3c77459dc156
Copy up to a certain bsize, otherwise set to a fixed bsize.
This helsp to reduce artifact near moving boundary caused by full partition
copy without checking motion of super-block.
This artifact can occur at speeds 3,4 in real-time mode.
Issue: https://code.google.com/p/webm/issues/detail?id=738.
Change-Id: I05812521fd38816a467f72eb6a951cae4c227931
This commit reduces the frequency of frames using finer quantizer
in non-RD coding flow, and slightly tune up the quantizer resolution
when used. It provides 1.7% compression gains in speed -5 at no speed
difference.
Change-Id: I430249a51260a841a0402666e5ec1566e4f7d5a6
The new tolerance is a little higher than before (especially
for kf/gf/arf) so this change gives an encode speed up
for some clips up for speeds 0-2.
Change-Id: I63f7d6c9cc11c7f58742f41e250dcd3eab1741eb
