tree 43254d1155c15cbb805ceba8fdc8960541adb247
parent 24f62e8d69eac1a8ba3f30b12c4716414a493f51
author Ranjit Kumar Tulabandu <ranjit.tulabandu@ittiam.com> 1672985149 +0530
committer Yunqing Wang <yunqingwang@google.com> 1673031346 +0000

Simplify rate computation in rate_estimator()

The rate computation in rate_estimator() function
accumulates (log(abs_level + 1.0) / log(2.0)) for each of
the quantized coefficients. This is replaced by
get_msb(abs_level + 1) to enable the usage of built-in
platform-specific instructions.

For 'good' encoding,
               Instruction Count        BD-Rate Loss(%)
cpu Resolution   Reduction(%)    avg.psnr  ovr.psnr   ssim
 3   LOWRES2       0.407         0.0000     0.0000    0.0000
 3   MIDRES2       0.273         0.0000     0.0000    0.0000
 3    HDRES2       0.174         0.0000     0.0000    0.0000
 4   LOWRES2       0.705         0.0000     0.0000    0.0000
 4   MIDRES2       0.466         0.0000     0.0000    0.0000
 4    HDRES2       0.312         0.0000     0.0000    0.0000
 5   LOWRES2       1.365         0.0000     0.0000    0.0000
 5   MIDRES2       0.881         0.0000     0.0000    0.0000
 5    HDRES2       0.594         0.0000     0.0000    0.0000
 6   LOWRES2       1.841         0.0000     0.0000    0.0000
 6   MIDRES2       1.190         0.0000     0.0000    0.0000
 6    HDRES2       0.802         0.0000     0.0000    0.0000

STATS_CHANGED possible, but not seen

Change-Id: Ie9f4a94c76436a1c2a6c9f4c34ed7898ddc3a3d7