From bd3ab3abe640796b65422b18a3751b7dfb814680 Mon Sep 17 00:00:00 2001
From: Frank Galligan <fgalligan@google.com>
Date: Fri, 29 Apr 2016 11:51:16 -0700
Subject: [PATCH] Add flag to estimate last frame's duration to stats.

BUG=https://bugs.chromium.org/p/webm/issues/detail?id=1204

Change-Id: Ie73e2981951f9eb6140bdfb0a6839320e009b7fe
---
 common/vp9_level_stats.cc       | 13 +++++++++++--
 common/vp9_level_stats.h        | 15 ++++++++++++++-
 common/vp9_level_stats_tests.cc | 11 +++++++++--
 webm_info.cc                    |  2 +-
 4 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/common/vp9_level_stats.cc b/common/vp9_level_stats.cc
index 7459a85..79ef967 100644
--- a/common/vp9_level_stats.cc
+++ b/common/vp9_level_stats.cc
@@ -211,9 +211,18 @@ int64_t Vp9LevelStats::GetMaxLumaPictureSize() const {
 }
 
 double Vp9LevelStats::GetAverageBitRate() const {
-  const double duration_seconds =
-      ((duration_ns_ == -1) ? end_ns_ - start_ns_ : duration_ns_) /
+  const int64_t frame_duration_ns = end_ns_ - start_ns_;
+  double duration_seconds =
+      ((duration_ns_ == -1) ? frame_duration_ns : duration_ns_) /
       libwebm::kNanosecondsPerSecond;
+  if (estimate_last_frame_duration_ &&
+      (duration_ns_ == -1 || duration_ns_ <= frame_duration_ns)) {
+    const double sec_per_frame = frame_duration_ns /
+                                 libwebm::kNanosecondsPerSecond /
+                                 (displayed_frames - 1);
+    duration_seconds += sec_per_frame;
+  }
+
   return total_compressed_size_ / duration_seconds / 125.0;
 }
 
diff --git a/common/vp9_level_stats.h b/common/vp9_level_stats.h
index a106851..143dc44 100644
--- a/common/vp9_level_stats.h
+++ b/common/vp9_level_stats.h
@@ -87,7 +87,8 @@ class Vp9LevelStats {
         total_uncompressed_bits_(0),
         frames_refreshed_(0),
         max_frames_refreshed_(0),
-        max_column_tiles_(0) {}
+        max_column_tiles_(0),
+        estimate_last_frame_duration_(true) {}
 
   ~Vp9LevelStats() = default;
   Vp9LevelStats(Vp9LevelStats&& other) = delete;
@@ -135,6 +136,16 @@ class Vp9LevelStats {
   // as the duration.
   void set_duration(int64_t time_ns) { duration_ns_ = time_ns; }
 
+  bool estimate_last_frame_duration() const {
+    return estimate_last_frame_duration_;
+  }
+
+  // If true try to estimate the last frame's duration if the stream's duration
+  // is not set or the stream's duration equals the last frame's timestamp.
+  void set_estimate_last_frame_duration(bool flag) {
+    estimate_last_frame_duration_ = flag;
+  }
+
  private:
   int frames;
   int displayed_frames;
@@ -175,6 +186,8 @@ class Vp9LevelStats {
   int max_frames_refreshed_;
 
   int max_column_tiles_;
+
+  bool estimate_last_frame_duration_;
 };
 
 }  // namespace vp9_parser
diff --git a/common/vp9_level_stats_tests.cc b/common/vp9_level_stats_tests.cc
index 9f916e2..a1abed3 100644
--- a/common/vp9_level_stats_tests.cc
+++ b/common/vp9_level_stats_tests.cc
@@ -129,12 +129,16 @@ TEST_F(Vp9LevelStatsTests, VideoOnlyFile) {
   EXPECT_EQ(11, stats_.GetLevel());
   EXPECT_EQ(479232, stats_.GetMaxLumaSampleRate());
   EXPECT_EQ(36864, stats_.GetMaxLumaPictureSize());
-  EXPECT_DOUBLE_EQ(275.512, stats_.GetAverageBitRate());
+  EXPECT_DOUBLE_EQ(264.03233333333333, stats_.GetAverageBitRate());
   EXPECT_DOUBLE_EQ(147.136, stats_.GetMaxCpbSize());
   EXPECT_DOUBLE_EQ(20.873079938441883, stats_.GetCompressionRatio());
   EXPECT_EQ(1, stats_.GetMaxColumnTiles());
   EXPECT_EQ(11, stats_.GetMinimumAltrefDistance());
   EXPECT_EQ(3, stats_.GetMaxReferenceFrames());
+
+  EXPECT_TRUE(stats_.estimate_last_frame_duration());
+  stats_.set_estimate_last_frame_duration(false);
+  EXPECT_DOUBLE_EQ(275.512, stats_.GetAverageBitRate());
 }
 
 TEST_F(Vp9LevelStatsTests, Muxed) {
@@ -148,12 +152,15 @@ TEST_F(Vp9LevelStatsTests, Muxed) {
   EXPECT_EQ(30, stats_.GetLevel());
   EXPECT_EQ(9838080, stats_.GetMaxLumaSampleRate());
   EXPECT_EQ(409920, stats_.GetMaxLumaPictureSize());
-  EXPECT_DOUBLE_EQ(468.38413361169108, stats_.GetAverageBitRate());
+  EXPECT_DOUBLE_EQ(447.09394572025053, stats_.GetAverageBitRate());
   EXPECT_DOUBLE_EQ(118.464, stats_.GetMaxCpbSize());
   EXPECT_DOUBLE_EQ(263.10185597889068, stats_.GetCompressionRatio());
   EXPECT_EQ(2, stats_.GetMaxColumnTiles());
   EXPECT_EQ(9, stats_.GetMinimumAltrefDistance());
   EXPECT_EQ(3, stats_.GetMaxReferenceFrames());
+
+  stats_.set_estimate_last_frame_duration(false);
+  EXPECT_DOUBLE_EQ(468.38413361169108, stats_.GetAverageBitRate());
 }
 
 TEST_F(Vp9LevelStatsTests, SetDuration) {
diff --git a/webm_info.cc b/webm_info.cc
index eb212ef..0b991c6 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[] = "1.0.4.2";
+const char VERSION_STRING[] = "1.0.4.3";
 
 struct Options {
   Options();