Update CHANGELOG for v3.2.0-rc2

BUG=aomedia:3165

Change-Id: Iefcd62c1f4d14dda0b2151740468078fe0bdd834
diff --git a/CHANGELOG b/CHANGELOG
index 3fccfc1..551b09a 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,24 +1,32 @@
-2021-10-07 v3.2.0
+2021-10-11 v3.2.0
   This release includes compression efficiency and perceptual quality
   improvements, speedup and memory optimizations, as well as some new
   features.
 
   - New Features
-    * Introduced speeds 7, 8, and 9 for all-intra mode.
-    * Introduced speed 10 for real-time mode.
+    * Introduced speeds 7, 8, and 9 for all intra mode.
+    * Introduced speed 10 for real time mode.
     * Introduced an API that allows external partition decisions.
+    * SVC: added support for compound prediction.
+    * SVC: added support for fixed SVC modes.
 
   - Compression Efficiency Improvements
     * Intra-mode search improvement.
     * Improved real time (RT) mode BDrate savings by ~5% (RT speed 5)
       and ~12% (RT speed 6). The improvement was measured on the video
       conference set.
+    * Improved real time mode for nonrd path (speed 7, 8, 9): BDrate
+      gains of ~3-5%.
+    * Rate control and RD adjustments based on ML research in VP9.
+      Modest impact for low resolution but ~0.5-1.0% for HD.
 
   - Perceptual Quality Improvements
     * Added a new mode --deltaq-mode=3 to improve perceptual quality
       based on a differential contrast model for still images.
     * Added a new mode –deltaq-mode=4 to improve perceptual quality
       based on user rated cq_level data set for still images.
+    * Weighting of some intra mode and partition size choices to better
+      manage and retain texture.
 
   - Speedup and Memory Optimizations
     * Further improved 2-pass good quality encoder speed:
@@ -32,6 +40,10 @@
       o RT speed 5 speedup: 110%
       o RT speed 6 speedup: 77%
 
+  - Bug Fixes
+    * Issue 3069: Fix one-pass mode keyframe placement off-by-one error.
+    * Issue 3156: Fix a bug in av1_quantize_lp AVX2 optimization.
+
 2021-09-29 v3.1.3
   This release includes several bug fixes.