From faf89d4ed191f71378840a67292d6c269e2c0a3d Mon Sep 17 00:00:00 2001
From: Frank Galligan <fgalligan@google.com>
Date: Fri, 29 Apr 2016 16:01:34 -0700
Subject: [PATCH] Add MaxLumaSampleRate grace percent to stats.

BUG=https://bugs.chromium.org/p/webm/issues/detail?id=1206

Change-Id: I29a956871bd5aa0c7b493601ed23b44a08414d32
---
 common/vp9_level_stats.cc |  5 ++++-
 common/vp9_level_stats.h  | 16 +++++++++++++++-
 webm_info.cc              |  2 +-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/common/vp9_level_stats.cc b/common/vp9_level_stats.cc
index 79ef967..f9bd53a 100644
--- a/common/vp9_level_stats.cc
+++ b/common/vp9_level_stats.cc
@@ -132,8 +132,11 @@ Vp9Level Vp9LevelStats::GetLevel() const {
 
   int level_index = 0;
   Vp9Level max_level = LEVEL_UNKNOWN;
+  const double grace_multiplier =
+      max_luma_sample_rate_grace_percent_ / 100.0 + 1.0;
   for (int i = 0; i < kNumVp9Levels; ++i) {
-    if (max_luma_sample_rate <= Vp9LevelTable[i].max_luma_sample_rate) {
+    if (max_luma_sample_rate <=
+        Vp9LevelTable[i].max_luma_sample_rate * grace_multiplier) {
       if (max_level < Vp9LevelTable[i].level) {
         max_level = Vp9LevelTable[i].level;
         level_index = i;
diff --git a/common/vp9_level_stats.h b/common/vp9_level_stats.h
index 143dc44..bc8c534 100644
--- a/common/vp9_level_stats.h
+++ b/common/vp9_level_stats.h
@@ -73,6 +73,7 @@ class Vp9LevelStats {
         current_luma_size_(0),
         max_luma_size_(0),
         max_luma_end_ns_(0),
+        max_luma_sample_rate_grace_percent_(1.5),
         first_altref(true),
         frames_since_last_altref(0),
         minimum_altref_distance(std::numeric_limits<int>::max()),
@@ -135,7 +136,12 @@ class Vp9LevelStats {
   // not explictly set by this function then this class will use end - start
   // as the duration.
   void set_duration(int64_t time_ns) { duration_ns_ = time_ns; }
-
+  double max_luma_sample_rate_grace_percent() const {
+    return max_luma_sample_rate_grace_percent_;
+  }
+  void set_max_luma_sample_rate_grace_percent(double percent) {
+    max_luma_sample_rate_grace_percent_ = percent;
+  }
   bool estimate_last_frame_duration() const {
     return estimate_last_frame_duration_;
   }
@@ -164,6 +170,14 @@ class Vp9LevelStats {
   int64_t max_luma_size_;
   int64_t max_luma_end_ns_;
 
+  // MaxLumaSampleRate = (ExampleFrameRate + ExampleFrameRate /
+  // MinimumAltrefDistance) * MaxLumaPictureSize. For levels 1-4
+  // ExampleFrameRate / MinimumAltrefDistance is non-integer, so using a sliding
+  // window of one frame to calculate MaxLumaSampleRate may have frames >
+  // (ExampleFrameRate + ExampleFrameRate / MinimumAltrefDistance) in the
+  // window. In order to address this issue, a grace percent of 1.5 was added.
+  double max_luma_sample_rate_grace_percent_;
+
   bool first_altref;
   int frames_since_last_altref;
   int minimum_altref_distance;
diff --git a/webm_info.cc b/webm_info.cc
index 0b991c6..424553a 100644
--- a/webm_info.cc
+++ b/webm_info.cc
@@ -35,7 +35,7 @@ using libwebm::Indent;
 using libwebm::kNanosecondsPerSecond;
 using libwebm::kNanosecondsPerSecondi;
 
-const char VERSION_STRING[] = "1.0.4.3";
+const char VERSION_STRING[] = "1.0.4.4";
 
 struct Options {
   Options();