Update CHANGELOG for libaom v3.12.0

Bug: 394596176
Change-Id: I8e3c4194090a0d2941ab936065441e298f1ea906

CHANGELOG

diff --git a/CHANGELOG b/CHANGELOG
index e8563bb..275e500 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,6 @@
-2025-02-05 v3.12.0
+2025-02-06 v3.12.0
   This release includes new codec interfaces, compression efficiency and
-  perceptual improvements, speedup and memory optimizations and many bug
+  perceptual improvements, speedup and memory optimizations, and bug
   fixes. This release is ABI compatible with the last release.
 
   Five internal functions (aom_free, aom_malloc, aom_wb_bytes_written,
@@ -9,6 +9,53 @@
   these internal functions from the ABI is a bug fix and does not break
   ABI compatibility.
 
+  Acknowledgment: The image quality optimizations in the new tuning
+  option AOM_TUNE_IQ were originally developed for SVT-AV1-PSY by
+  Cole Ogaard, Gianni Rosato, Julio Barba, and Zakaria Djebrouni.
+
+  - New Features
+    * New tuning option AOM_TUNE_IQ (image quality) for the
+      AOME_SET_TUNING codec control (--tune=iq) in all-intra mode. The
+      feature detection macro AOM_HAVE_TUNE_IQ, if defined, indicates
+      that AOM_TUNE_IQ is available.
+    * In all-intra mode, the AOME_SET_SHARPNESS codec control now also
+      sets the loop_filter_sharpness syntax element in the bitstream.
+      Larger values increasingly reduce how much the filtering can
+      change the sample values on block edges to favor perceived
+      sharpness.
+    * In all-intra mode, the default value of the AV1E_SET_QM_MIN codec
+      control is decreased to 4, and the default value of the
+      AV1E_SET_QM_MAX codec control is increased to 10. The default
+      values in good-quality and realtime modes remain unchanged (5 and
+      9, respectively).
+    * New value 3 for the AV1E_SET_ENABLE_CDEF codec control
+      (--enable-cdef): Enable CDEF adaptively based on frame qindex.
+    * New value 6 for the AV1E_SET_DELTAQ_MODE codec control
+      (--deltaq-mode): use modulation for all intra using Variance
+      Boost.
+
+  - Compression Efficiency Improvements
+    * Tuning mode AOM_TUNE_IQ improves image compression efficiency on
+      the CLIC dataset by up to 12% for the same SSIMULACRA 2 score, up
+      to 14% for the same DSSIM score, and up to 17% for the same
+      Butteraugli score.
+
+  - Perceptual Quality Improvements
+    * Adjust temporal filter strength for better visual quality.
+
+  - Speedup and Memory Optimizations
+    * Add the CDEF optimization for RISC-V.
+    * Help the compiler generate better vectorized code for variance
+      calculation and warped motion in generic CPU builds.
+    * Make several arrays const.
+
+  - Other Improvements
+    * Build: compile source files in parallel under MSVC.
+
+  - Bug Fixes
+    * Fix bug where metadata added with aom_img_add_metadata was lost
+      when frame scaling was used.
+
 2024-10-24 v3.11.0
   This release includes perceptual quality improvements, binary size reduction
   under certain configurations and many bug fixes. This release changes the