BlankDetectorDesktopCapturerWrapper to detect a blank DesktopFrame

webrtc/modules/desktop_capture/blank_detector_desktop_capturer_wrapper_unittest.cc

+/*
+ *  Copyright (c) 2017 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/modules/desktop_capture/blank_detector_desktop_capturer_wrapper.h"
+
+#include <memory>
+#include <utility>
+
+#include "webrtc/modules/desktop_capture/desktop_capturer.h"
+#include "webrtc/modules/desktop_capture/desktop_frame.h"
+#include "webrtc/modules/desktop_capture/desktop_frame_generator.h"
+#include "webrtc/modules/desktop_capture/fake_desktop_capturer.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+class BlankDetectorDesktopCapturerWrapperTest
+    : public testing::Test,
+      public DesktopCapturer::Callback {
+ public:
+  BlankDetectorDesktopCapturerWrapperTest();
+  ~BlankDetectorDesktopCapturerWrapperTest() override;
+
+ protected:
+  void PerfTest(DesktopCapturer* capturer);
+
+  const int frame_width_ = 1024;
+  const int frame_height_ = 768;
+  const int permanent_failure_threshold_ = 100;
+  std::unique_ptr<BlankDetectorDesktopCapturerWrapper> wrapper_;
+  DesktopCapturer* capturer_ = nullptr;
+  BlackWhiteDesktopFramePainter painter_;
+  int num_frames_captured_ = 0;
+  DesktopCapturer::Result last_result_ = DesktopCapturer::Result::SUCCESS;
+  std::unique_ptr<DesktopFrame> last_frame_;
+
+ private:
+  // DesktopCapturer::Callback interface.
+  void OnCaptureResult(DesktopCapturer::Result result,
+                       std::unique_ptr<DesktopFrame> frame) override;
+
+  PainterDesktopFrameGenerator frame_generator_;
+};
+
+BlankDetectorDesktopCapturerWrapperTest::
+    BlankDetectorDesktopCapturerWrapperTest() {
+  frame_generator_.size()->set(frame_width_, frame_height_);
+  frame_generator_.set_desktop_frame_painter(&painter_);
+  std::unique_ptr<DesktopCapturer> capturer(new FakeDesktopCapturer());
+  FakeDesktopCapturer* fake_capturer =
+      static_cast<FakeDesktopCapturer*>(capturer.get());
+  fake_capturer->set_frame_generator(&frame_generator_);
+  capturer_ = fake_capturer;
+  wrapper_.reset(new BlankDetectorDesktopCapturerWrapper(
+      std::move(capturer), RgbaColor(0, 0, 0, 0),
+      permanent_failure_threshold_));
+  wrapper_->Start(this);
+}
+
+BlankDetectorDesktopCapturerWrapperTest::
+    ~BlankDetectorDesktopCapturerWrapperTest() = default;
+
+void BlankDetectorDesktopCapturerWrapperTest::OnCaptureResult(
+    DesktopCapturer::Result result,
+    std::unique_ptr<DesktopFrame> frame) {
+  last_result_ = result;
+  last_frame_ = std::move(frame);
+  num_frames_captured_++;
+}
+
+void BlankDetectorDesktopCapturerWrapperTest::PerfTest(
+    DesktopCapturer* capturer) {
+  for (int i = 0; i < 10000; i++) {
+    // According to the implementation detail, this pixel is checked at last.
+    painter_.updated_region()->AddRect(
+        DesktopRect::MakeXYWH(frame_width_ >> 1, frame_height_ >> 1, 1, 1));
+    capturer->CaptureFrame();
+    ASSERT_EQ(num_frames_captured_, i + 1);
+    ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+    ASSERT_TRUE(last_frame_);
+  }
+}
+
+TEST_F(BlankDetectorDesktopCapturerWrapperTest, ShouldDetectBlankFrame) {
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 1);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::ERROR_TEMPORARY);
+  ASSERT_FALSE(last_frame_);
+}
+
+TEST_F(BlankDetectorDesktopCapturerWrapperTest, ShouldPassBlankDetection) {
+  painter_.updated_region()->AddRect(DesktopRect::MakeXYWH(0, 0, 10, 10));
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 1);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+  ASSERT_TRUE(last_frame_);
+
+  painter_.updated_region()->AddRect(
+      DesktopRect::MakeXYWH(frame_width_ - 10, frame_height_ - 10, 10, 10));
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 2);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+  ASSERT_TRUE(last_frame_);
+
+  painter_.updated_region()->AddRect(
+      DesktopRect::MakeXYWH(0, frame_height_ - 10, 10, 10));
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 3);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+  ASSERT_TRUE(last_frame_);
+
+  painter_.updated_region()->AddRect(
+      DesktopRect::MakeXYWH(frame_width_ - 10, 0, 10, 10));
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 4);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+  ASSERT_TRUE(last_frame_);
+
+  painter_.updated_region()->AddRect(DesktopRect::MakeXYWH(
+      (frame_width_ >> 1) - 5, (frame_height_ >> 1) - 5, 10, 10));
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, 5);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::SUCCESS);
+  ASSERT_TRUE(last_frame_);
+}
+
+TEST_F(BlankDetectorDesktopCapturerWrapperTest, ShouldReturnPermanentError) {
+  for (int i = 0; i < permanent_failure_threshold_ - 1; i++) {
+    wrapper_->CaptureFrame();
+    ASSERT_EQ(num_frames_captured_, i + 1);
+    ASSERT_EQ(last_result_, DesktopCapturer::Result::ERROR_TEMPORARY);
+    ASSERT_FALSE(last_frame_);
+  }
+  wrapper_->CaptureFrame();
+  ASSERT_EQ(num_frames_captured_, permanent_failure_threshold_);
+  ASSERT_EQ(last_result_, DesktopCapturer::Result::ERROR_PERMANENT);
+  ASSERT_FALSE(last_frame_);
+}
+
+// There is no perceptible impact by using BlankDetectorDesktopCapturerWrapper.
+// i.e. less than 0.01ms per frame.
+// [ OK ] DISABLED_Performance (8555 ms)
+// [ OK ] DISABLED_PerformanceComparison (8456 ms)
+TEST_F(BlankDetectorDesktopCapturerWrapperTest, DISABLED_Performance) {
+  PerfTest(wrapper_.get());
+}
+
+TEST_F(BlankDetectorDesktopCapturerWrapperTest,
+       DISABLED_PerformanceComparison) {
+  capturer_->Start(this);
+  PerfTest(capturer_);
+}
+
+}  // namespace webrtc