Work on flexible mode and screen sharing.

webrtc/modules/video_coding/codecs/vp9/screenshare_layers_unittest.cc

+/*
+ *  Copyright (c) 2015 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 "testing/gtest/include/gtest/gtest.h"
+#include "vpx/vp8cx.h"
+#include "webrtc/base/logging.h"
+#include "webrtc/modules/video_coding/codecs/vp9/screenshare_layers.h"
+#include "webrtc/modules/video_coding/codecs/vp9/vp9_impl.h"
+#include "webrtc/system_wrappers/interface/clock.h"
+
+namespace webrtc {
+
+typedef VP9EncoderImpl::SuperFrameRefSettings Settings;
+
+const uint32_t kTickFrequency = 90000;
+
+class ScreenshareLayerTestVP9 : public ::testing::Test {
+ protected:
+  ScreenshareLayerTestVP9() : clock_(1000) {}
+  virtual ~ScreenshareLayerTestVP9() {}
+
+  void InitScreenshareLayers(int layers) {
+    layers_.reset(new ScreenshareLayersVP9(layers));
+  }
+
+  void ConfigureBitrateForLayer(int kbps, uint8_t layer_id) {
+    layers_->ConfigureBitrate(kbps, layer_id);
+  }
+
+  void AdvanceTime(int64_t milliseconds) {
+    clock_.AdvanceTimeMilliseconds(milliseconds);
+  }
+
+  void AddKilobitsToLayer(int kilobits, uint8_t layer_id) {
+    // 1000 bits = 125 bytes
+    layers_->LayerFrameEncoded(kilobits * 125, layer_id);
+  }
+
+  void EqualRefsForLayer(const Settings& actual, uint8_t layer_id) {
+    EXPECT_EQ(expected_.layer[layer_id].upd_buf,
+              actual.layer[layer_id].upd_buf);
+    EXPECT_EQ(expected_.layer[layer_id].ref_buf1,
+              actual.layer[layer_id].ref_buf1);
+    EXPECT_EQ(expected_.layer[layer_id].ref_buf2,
+              actual.layer[layer_id].ref_buf2);
+    EXPECT_EQ(expected_.layer[layer_id].ref_buf3,
+              actual.layer[layer_id].ref_buf3);
+  }
+
+  void EqualRefs(const Settings& actual) {
+    for (unsigned int layer_id = 0; layer_id < kMaxVp9NumberOfSpatialLayers;
+         ++layer_id) {
+      EqualRefsForLayer(actual, layer_id);
+    }
+  }
+
+  void EqualStartStopKeyframe(const Settings& actual) {
+    EXPECT_EQ(expected_.start_layer, actual.start_layer);
+    EXPECT_EQ(expected_.stop_layer, actual.stop_layer);
+    EXPECT_EQ(expected_.is_keyframe, actual.is_keyframe);
+  }
+
+  // Check that the settings returned by GetSuperFrameSettings() is
+  // equal to the expected_ settings.
+  void EqualToExpected() {
+    uint32_t frame_timestamp_ =
+        clock_.TimeInMilliseconds() * (kTickFrequency / 1000);
+    Settings actual =
+        layers_->GetSuperFrameSettings(frame_timestamp_, expected_.is_keyframe);
+    EqualRefs(actual);
+    EqualStartStopKeyframe(actual);
+  }
+
+  Settings expected_;
+  SimulatedClock clock_;
+  rtc::scoped_ptr<ScreenshareLayersVP9> layers_;
+};
+
+TEST_F(ScreenshareLayerTestVP9, NoRefsOnKeyFrame) {
+  const int kNumLayers = kMaxVp9NumberOfSpatialLayers;
+  InitScreenshareLayers(kNumLayers);
+  expected_.start_layer = 0;
+  expected_.stop_layer = kNumLayers - 1;
+
+  for (int l = 0; l < kNumLayers; ++l) {
+    expected_.layer[l].upd_buf = l;
+  }
+  expected_.is_keyframe = true;
+  EqualToExpected();
+
+  for (int l = 0; l < kNumLayers; ++l) {
+    expected_.layer[l].ref_buf1 = l;
+  }
+  expected_.is_keyframe = false;
+  EqualToExpected();
+}
+
+// Test if it is possible to send at a high bitrate (over the threshold)
+// after a longer period of low bitrate. This should not be possible.
+TEST_F(ScreenshareLayerTestVP9, DontAccumelateAvailableBitsOverTime) {
+  InitScreenshareLayers(2);
+  ConfigureBitrateForLayer(100, 0);
+
+  expected_.layer[0].upd_buf = 0;
+  expected_.layer[0].ref_buf1 = 0;
+  expected_.layer[1].upd_buf = 1;
+  expected_.layer[1].ref_buf1 = 1;
+  expected_.start_layer = 0;
+  expected_.stop_layer = 1;
+
+  // Send 10 frames at a low bitrate (50 kbps)
+  for (int i = 0; i < 10; ++i) {
+    AdvanceTime(200);
+    EqualToExpected();
+    AddKilobitsToLayer(10, 0);
+  }
+
+  AdvanceTime(200);
+  EqualToExpected();
+  AddKilobitsToLayer(301, 0);
+
+  // Send 10 frames at a high bitrate (200 kbps)
+  expected_.start_layer = 1;
+  for (int i = 0; i < 10; ++i) {
+    AdvanceTime(200);
+    EqualToExpected();
+    AddKilobitsToLayer(40, 1);
+  }
+}
+
+// Test if used bits are accumelated over layers, as they should;
+TEST_F(ScreenshareLayerTestVP9, AccumelateUsedBitsOverLayers) {
+  const int kNumLayers = kMaxVp9NumberOfSpatialLayers;
+  InitScreenshareLayers(kNumLayers);
+  for (int l = 0; l < kNumLayers - 1; ++l)
+    ConfigureBitrateForLayer(100, l);
+  for (int l = 0; l < kNumLayers; ++l) {
+    expected_.layer[l].upd_buf = l;
+    expected_.layer[l].ref_buf1 = l;
+  }
+
+  expected_.start_layer = 0;
+  expected_.stop_layer = kNumLayers - 1;
+  EqualToExpected();
+
+  for (int l = 0; l < kNumLayers - 1; ++l) {
+    expected_.start_layer = l;
+    EqualToExpected();
+    AddKilobitsToLayer(101, l);
+  }
+}
+
+// General testing of the bitrate controller.
+TEST_F(ScreenshareLayerTestVP9, 2LayerBitrate) {
+  InitScreenshareLayers(2);
+  ConfigureBitrateForLayer(100, 0);
+
+  expected_.layer[0].upd_buf = 0;
+  expected_.layer[1].upd_buf = 1;
+  expected_.layer[0].ref_buf1 = -1;
+  expected_.layer[1].ref_buf1 = -1;
+  expected_.start_layer = 0;
+  expected_.stop_layer = 1;
+
+  expected_.is_keyframe = true;
+  EqualToExpected();
+  AddKilobitsToLayer(100, 0);
+
+  expected_.layer[0].ref_buf1 = 0;
+  expected_.layer[1].ref_buf1 = 1;
+  expected_.is_keyframe = false;
+  AdvanceTime(199);
+  EqualToExpected();
+  AddKilobitsToLayer(100, 0);
+
+  expected_.start_layer = 1;
+  for (int frame = 0; frame < 3; ++frame) {
+    AdvanceTime(200);
+    EqualToExpected();
+    AddKilobitsToLayer(100, 1);
+  }
+
+  // Just before enough bits become available for L0 @0.999 seconds.
+  AdvanceTime(199);
+  EqualToExpected();
+  AddKilobitsToLayer(100, 1);
+
+  // Just after enough bits become available for L0 @1.0001 seconds.
+  expected_.start_layer = 0;
+  AdvanceTime(2);
+  EqualToExpected();
+  AddKilobitsToLayer(100, 0);
+
+  // Keyframes always encode all layers, even if it is over budget.
+  expected_.layer[0].ref_buf1 = -1;
+  expected_.layer[1].ref_buf1 = -1;
+  expected_.is_keyframe = true;
+  AdvanceTime(499);
+  EqualToExpected();
+  expected_.layer[0].ref_buf1 = 0;
+  expected_.layer[1].ref_buf1 = 1;
+  expected_.start_layer = 1;
+  expected_.is_keyframe = false;
+  EqualToExpected();
+  AddKilobitsToLayer(100, 0);
+
+  // 400 kb in L0 --> @3 second mark to fall below the threshold..
+  // just before @2.999 seconds.
+  expected_.is_keyframe = false;
+  AdvanceTime(1499);
+  EqualToExpected();
+  AddKilobitsToLayer(100, 1);
+
+  // just after @3.001 seconds.
+  expected_.start_layer = 0;
+  AdvanceTime(2);
+  EqualToExpected();
+  AddKilobitsToLayer(100, 0);
+}
+
+// General testing of the bitrate controller.
+TEST_F(ScreenshareLayerTestVP9, 3LayerBitrate) {
+  InitScreenshareLayers(3);
+  ConfigureBitrateForLayer(100, 0);
+  ConfigureBitrateForLayer(100, 1);
+
+  for (int l = 0; l < 3; ++l) {
+    expected_.layer[l].upd_buf = l;
+    expected_.layer[l].ref_buf1 = l;
+  }
+  expected_.start_layer = 0;
+  expected_.stop_layer = 2;
+
+  EqualToExpected();
+  AddKilobitsToLayer(105, 0);
+  AddKilobitsToLayer(30, 1);
+
+  AdvanceTime(199);
+  EqualToExpected();
+  AddKilobitsToLayer(105, 0);
+  AddKilobitsToLayer(30, 1);
+
+  expected_.start_layer = 1;
+  AdvanceTime(200);
+  EqualToExpected();
+  AddKilobitsToLayer(130, 1);
+
+  expected_.start_layer = 2;
+  AdvanceTime(200);
+  EqualToExpected();
+
+  // 400 kb in L1 --> @1.0 second mark to fall below threshold.
+  // 210 kb in L0 --> @1.1 second mark to fall below threshold.
+  // Just before L1 @0.999 seconds.
+  AdvanceTime(399);
+  EqualToExpected();
+
+  // Just after L1 @1.001 seconds.
+  expected_.start_layer = 1;
+  AdvanceTime(2);
+  EqualToExpected();
+
+  // Just before L0 @1.099 seconds.
+  AdvanceTime(99);
+  EqualToExpected();
+
+  // Just after L0 @1.101 seconds.
+  expected_.start_layer = 0;
+  AdvanceTime(2);
+  EqualToExpected();
+
+  // @1.1 seconds
+  AdvanceTime(99);
+  EqualToExpected();
+  AddKilobitsToLayer(200, 1);
+
+  expected_.is_keyframe = true;
+  for (int l = 0; l < 3; ++l)
+    expected_.layer[l].ref_buf1 = -1;
+  AdvanceTime(200);
+  EqualToExpected();
+
+  expected_.is_keyframe = false;
+  expected_.start_layer = 2;
+  for (int l = 0; l < 3; ++l)
+    expected_.layer[l].ref_buf1 = l;
+  AdvanceTime(200);
+  EqualToExpected();
+}
+
+}  // namespace webrtc