Repository: electron/electron
Pull request: fix: osr stutter fix backport for electron.

Backport of #45572

See that PR for details.


Notes: Backport fix for a upstream bug that cause Offscreen Rendering to stutter.


Changed files:
filename: patches/chromium/.patches
patch: @@ -146,3 +146,4 @@ cherry-pick-3a6ff45cc3f4.patch
 cherry-pick-a51e7ebb7663.patch
 cherry-pick-f3300abe2fcd.patch
 remove_persistentmemoryallocator_getallocsize.patch
+fix_osr_stutter_in_both_cpu_and_gpu_capture_when_page_has_animation.patch

filename: patches/chromium/fix_osr_stutter_in_both_cpu_and_gpu_capture_when_page_has_animation.patch
patch: @@ -0,0 +1,236 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: reito <cnschwarzer@qq.com>
+Date: Wed, 12 Feb 2025 20:42:02 +0800
+Subject: fix: osr stutter in both cpu and gpu capture when page has animation.
+
+https://crrev.org/c/6232721
+https://crbug.com/391118566
+There's bug in VideoCaptureOracle that cause stutter in both cpu and gpu capture when page has animation.
+The upstream has a fix, which will be available in Chromium M135.
+Backport this fix for Electron versions before that.
+
+diff --git a/media/capture/content/video_capture_oracle.cc b/media/capture/content/video_capture_oracle.cc
+index dad9598799a670b3cfb14965bc8a7b4ea3b4f95f..05a82788ae1e5c304ee150a2390f346d7b454630 100644
+--- a/media/capture/content/video_capture_oracle.cc
++++ b/media/capture/content/video_capture_oracle.cc
+@@ -118,8 +118,9 @@ void VideoCaptureOracle::SetCaptureSizeConstraints(
+ void VideoCaptureOracle::SetAutoThrottlingEnabled(bool enabled) {
+   const bool was_enabled =
+       (capture_size_throttling_mode_ != kThrottlingDisabled);
+-  if (was_enabled == enabled)
++  if (was_enabled == enabled) {
+     return;
++  }
+   capture_size_throttling_mode_ =
+       enabled ? kThrottlingEnabled : kThrottlingDisabled;
+   VLOG(1) << "Capture size auto-throttling is now "
+@@ -127,19 +128,22 @@ void VideoCaptureOracle::SetAutoThrottlingEnabled(bool enabled) {
+ 
+   // When not auto-throttling, have the CaptureResolutionChooser target the max
+   // resolution within constraints.
+-  if (!enabled)
++  if (!enabled) {
+     resolution_chooser_.SetTargetFrameArea(std::numeric_limits<int>::max());
++  }
+ 
+-  if (next_frame_number_ > 0)
++  if (next_frame_number_ > 0) {
+     CommitCaptureSizeAndReset(GetFrameTimestamp(next_frame_number_ - 1));
++  }
+ }
+ 
+ void VideoCaptureOracle::SetSourceSize(const gfx::Size& source_size) {
+   resolution_chooser_.SetSourceSize(source_size);
+   // If the |resolution_chooser_| computed a new capture size, that will become
+   // visible via a future call to ObserveEventAndDecideCapture().
+-  source_size_change_time_ = (next_frame_number_ == 0) ?
+-      base::TimeTicks() : GetFrameTimestamp(next_frame_number_ - 1);
++  source_size_change_time_ = (next_frame_number_ == 0)
++                                 ? base::TimeTicks()
++                                 : GetFrameTimestamp(next_frame_number_ - 1);
+ }
+ 
+ bool VideoCaptureOracle::ObserveEventAndDecideCapture(
+@@ -172,6 +176,15 @@ bool VideoCaptureOracle::ObserveEventAndDecideCapture(
+         if (should_sample) {
+           event_time = content_sampler_.frame_timestamp();
+           duration_of_next_frame_ = content_sampler_.sampling_period();
++        } else {
++          // https://crbug.com/391118566
++          // The content sampler may not sample the frame, if the
++          // `detected_region_` does not match the `damage_rect`. In this case,
++          // the capture may halt up to kNonAnimatingThreshold (250ms) and cause
++          // the video stutter, until it recovers and do another animation
++          // detection. To avoid this, we should use the smoothing sampler as a
++          // fallback to prevent the bad output.
++          should_sample = smoothing_sampler_.ShouldSample();
+         }
+         last_time_animation_was_detected_ = event_time;
+       } else {
+@@ -198,8 +211,9 @@ bool VideoCaptureOracle::ObserveEventAndDecideCapture(
+       NOTREACHED();
+   }
+ 
+-  if (!should_sample)
++  if (!should_sample) {
+     return false;
++  }
+ 
+   // If the exact duration of the next frame has not been determined, estimate
+   // it using the difference between the current and last frame.
+@@ -373,16 +387,18 @@ void VideoCaptureOracle::RecordConsumerFeedback(
+ 
+   // resource_utilization feedback.
+ 
+-  if (capture_size_throttling_mode_ == kThrottlingDisabled)
++  if (capture_size_throttling_mode_ == kThrottlingDisabled) {
+     return;
++  }
+ 
+   if (!std::isfinite(feedback.resource_utilization)) {
+     LOG(DFATAL) << "Non-finite utilization provided by consumer for frame #"
+                 << frame_number << ": " << feedback.resource_utilization;
+     return;
+   }
+-  if (feedback.resource_utilization <= 0.0)
++  if (feedback.resource_utilization <= 0.0) {
+     return;  // Non-positive values are normal, meaning N/A.
++  }
+ 
+   if (capture_size_throttling_mode_ != kThrottlingActive) {
+     VLOG(1) << "Received consumer feedback at frame #" << frame_number
+@@ -553,12 +569,14 @@ int VideoCaptureOracle::AnalyzeForIncreasedArea(base::TimeTicks analyze_time) {
+   const int current_area = capture_size_.GetArea();
+   const int increased_area =
+       resolution_chooser_.FindLargerFrameSize(current_area, 1).GetArea();
+-  if (increased_area <= current_area)
++  if (increased_area <= current_area) {
+     return -1;
++  }
+ 
+   // Determine whether the buffer pool could handle an increase in area.
+-  if (!HasSufficientRecentFeedback(buffer_pool_utilization_, analyze_time))
++  if (!HasSufficientRecentFeedback(buffer_pool_utilization_, analyze_time)) {
+     return -1;
++  }
+   if (buffer_pool_utilization_.current() > 0.0) {
+     const int buffer_capable_area = base::saturated_cast<int>(
+         current_area / buffer_pool_utilization_.current());
+@@ -593,8 +611,9 @@ int VideoCaptureOracle::AnalyzeForIncreasedArea(base::TimeTicks analyze_time) {
+ 
+   // At this point, the system is currently under-utilized.  Reset the start
+   // time if the system was not under-utilized when the last analysis was made.
+-  if (start_time_of_underutilization_.is_null())
++  if (start_time_of_underutilization_.is_null()) {
+     start_time_of_underutilization_ = analyze_time;
++  }
+ 
+   // If the under-utilization started soon after the last source size change,
+   // permit an immediate increase in the capture area.  This allows the system
+diff --git a/media/capture/content/video_capture_oracle_unittest.cc b/media/capture/content/video_capture_oracle_unittest.cc
+index 066676fa998db6782270ddbf42fe176d88eb30d4..6cd7567e91bc8c496846a685aa1506c7548f3a21 100644
+--- a/media/capture/content/video_capture_oracle_unittest.cc
++++ b/media/capture/content/video_capture_oracle_unittest.cc
+@@ -158,21 +158,26 @@ TEST(VideoCaptureOracleTest, TransitionsSmoothlyBetweenSamplers) {
+     const bool provide_animated_content_event =
+         (i % 100) >= 25 && (i % 100) < 75;
+ 
+-    // Only the few events that trigger the lock-out transition should be
+-    // dropped, because the AnimatedContentSampler doesn't yet realize the
+-    // animation ended.  Otherwise, the oracle should always decide to sample
+-    // because one of its samplers says to.
+-    const bool require_oracle_says_sample = (i % 100) < 75 || (i % 100) >= 78;
++    // https://crbug.com/391118566
++    // Previously the AnimatedContentSampler has a bug that cause jank.
++    // The oracle should always use SmoothEventSampler as a fallback. If
++    // AnimatedContentSampler doesn't yet realize the animation ended or
++    // doesn't keep up with the prediction it make, and it will wait for
++    // kNonAnimatingThreshold before it lock-out and hand over to smooth
++    // handler. This will cause the video to stutter and it is unacceptable.
++    // So, when the AnimatedContentSampler goes into wrong state, we now
++    // use SmoothEventSampler's decision as a fallback to prevent jank output
++    // and still has a overall limit on capture frequency.
+     const bool oracle_says_sample = oracle.ObserveEventAndDecideCapture(
+         VideoCaptureOracle::kCompositorUpdate,
+         provide_animated_content_event ? animation_damage_rect : gfx::Rect(),
+         t);
+-    if (require_oracle_says_sample)
+-      ASSERT_TRUE(oracle_says_sample);
+-    if (!oracle_says_sample) {
+-      ASSERT_EQ(base::TimeDelta(), oracle.estimated_frame_duration());
+-      continue;
+-    }
++
++    // Because we now use SmoothEventSampler as a fallback, oracle should
++    // always say sample. The previous AnimatedContentSampler lock-out
++    // dropped frame are now revived by SmoothEventSampler, since this test's
++    // capture frequency always meets min capture limit requirement.
++    ASSERT_TRUE(oracle_says_sample);
+     ASSERT_LT(base::TimeDelta(), oracle.estimated_frame_duration());
+ 
+     const int frame_number = oracle.next_frame_number();
+@@ -184,12 +189,9 @@ TEST(VideoCaptureOracleTest, TransitionsSmoothlyBetweenSamplers) {
+     if (!last_frame_timestamp.is_null()) {
+       const base::TimeDelta delta = frame_timestamp - last_frame_timestamp;
+       EXPECT_LE(event_increment.InMicroseconds(), delta.InMicroseconds());
+-      // Right after the AnimatedContentSampler lock-out transition, there were
+-      // a few frames dropped, so allow a gap in the timestamps.  Otherwise, the
+-      // delta between frame timestamps should never be more than 2X the
++      // The delta between frame timestamps should never be more than 2X the
+       // |event_increment|.
+-      const base::TimeDelta max_acceptable_delta =
+-          (i % 100) == 78 ? event_increment * 5 : event_increment * 2;
++      const base::TimeDelta max_acceptable_delta = event_increment * 2;
+       EXPECT_GE(max_acceptable_delta.InMicroseconds(), delta.InMicroseconds());
+     }
+     last_frame_timestamp = frame_timestamp;
+@@ -444,9 +446,9 @@ void RunAutoThrottleTest(bool is_content_animating,
+   // expect the resolution to remain constant.  Repeat.
+   for (int i = 0; i < 2; ++i) {
+     const gfx::Size starting_size = oracle.capture_size();
+-    SCOPED_TRACE(::testing::Message() << "Stepping down from "
+-                                      << starting_size.ToString()
+-                                      << ", i=" << i);
++    SCOPED_TRACE(::testing::Message()
++                 << "Stepping down from " << starting_size.ToString()
++                 << ", i=" << i);
+ 
+     gfx::Size stepped_down_size;
+     end_t = t + base::Seconds(10);
+@@ -471,9 +473,10 @@ void RunAutoThrottleTest(bool is_content_animating,
+       oracle.RecordCapture(with_consumer_feedback ? 0.25 : utilization);
+       base::TimeTicks ignored;
+       ASSERT_TRUE(oracle.CompleteCapture(frame_number, true, &ignored));
+-      if (with_consumer_feedback)
++      if (with_consumer_feedback) {
+         oracle.RecordConsumerFeedback(frame_number,
+                                       media::VideoCaptureFeedback(utilization));
++      }
+     }
+   }
+ 
+@@ -482,9 +485,9 @@ void RunAutoThrottleTest(bool is_content_animating,
+   // utilization and expect the resolution to remain constant.  Repeat.
+   for (int i = 0; i < 2; ++i) {
+     const gfx::Size starting_size = oracle.capture_size();
+-    SCOPED_TRACE(::testing::Message() << "Stepping up from "
+-                                      << starting_size.ToString()
+-                                      << ", i=" << i);
++    SCOPED_TRACE(::testing::Message()
++                 << "Stepping up from " << starting_size.ToString()
++                 << ", i=" << i);
+ 
+     gfx::Size stepped_up_size;
+     end_t = t + base::Seconds(is_content_animating ? 90 : 10);
+@@ -513,9 +516,10 @@ void RunAutoThrottleTest(bool is_content_animating,
+       oracle.RecordCapture(with_consumer_feedback ? 0.25 : utilization);
+       base::TimeTicks ignored;
+       ASSERT_TRUE(oracle.CompleteCapture(frame_number, true, &ignored));
+-      if (with_consumer_feedback)
++      if (with_consumer_feedback) {
+         oracle.RecordConsumerFeedback(frame_number,
+                                       media::VideoCaptureFeedback(utilization));
++      }
+     }
+   }
+ }