shithub: libvpx

Download patch

ref: 55db4f033f637e3e5ef326da5cf27e708b1336c0
parent: 8a4336ed2edea09b67f49828df1f8c526a85a7a6
author: Marco <marpan@google.com>
date: Thu Jan 4 09:20:59 EST 2018

vp9: Increase convergence speed of noise estimation.

Increase the recursive average factor from 15/16 to 3/4
to make the noise estimation respond faster.

Small/neglible change on low noise content, but better
denoising for noisy content.
Also encoder speedup of ~2-3% observed on some noisy clips.

Change-Id: I9dd02fe961ca24b411fe4c2732f814bf1e9a7f9f

--- a/vp9/encoder/vp9_noise_estimate.c

+++ b/vp9/encoder/vp9_noise_estimate.c

@@ -258,7 +258,7 @@

       // Normalize.

       avg_est = avg_est / num_samples;

       // Update noise estimate.

-      ne->value = (int)((15 * ne->value + avg_est) >> 4);

+      ne->value = (int)((3 * ne->value + avg_est) >> 2);

       ne->count++;

       if (ne->count == ne->num_frames_estimate) {

         // Reset counter and check noise level condition.