Update TestVideoRenderer with video decoding capabilities

remoting/test/test_video_renderer_unittest.cc

Index: remoting/test/test_video_renderer_unittest.cc
diff --git a/remoting/test/test_video_renderer_unittest.cc b/remoting/test/test_video_renderer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8c1d92f7fd04d30fefa57345ad3d167a0172310b
--- /dev/null
+++ b/remoting/test/test_video_renderer_unittest.cc
@@ -0,0 +1,272 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "remoting/test/test_video_renderer.h"
+
+#include <cmath>
+
+#include "base/memory/scoped_vector.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/timer/timer.h"
+#include "media/base/video_frame.h"
+#include "remoting/codec/video_encoder.h"
+#include "remoting/codec/video_encoder_verbatim.h"
+#include "remoting/codec/video_encoder_vpx.h"
+#include "remoting/proto/video.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
+#include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
+
+namespace {
+const int kBytesPerPixel = 4;
+const int kDefaultScreenWidth = 1024;
+const int kDefaultScreenHeight = 768;
+const double kDefaultErrorLimit = 0.02;
+}
+
+namespace remoting {
+namespace test {
+
+// Provides basic functionality for for the TestVideoRenderer Tests below.
+// This fixture also creates an MessageLoop to test decoding video packets.
+class TestVideoRendererTest : public testing::Test {
+ public:
+  TestVideoRendererTest();
+  ~TestVideoRendererTest() override;
+
+  // Generate a frame containing a gradient and test decoding of
+  // TestVideoRenderer. The original frame is compared to the one obtained from
+  // decoding the video packet, and the error at each pixel is the root mean
+  // square of the errors in the R, G and B components, each normalized to
+  // [0, 1]. This routine checks that the mean error over all pixels do not
+  // exceed a given limit.
+  void TestVideoPacketProcessing(int screen_width, int screen_height,
+                                 double error_limit);
+
+  // Generate a basic desktop frame containing a gradient.
+  scoped_ptr<webrtc::DesktopFrame> CreateDesktopFrameWithGradient(
+      int screen_width, int screen_height) const;
+
+ protected:
+  // Used to post tasks to the message loop.
+  scoped_ptr<base::RunLoop> run_loop_;
+
+  // Used to set timeouts and delays.
+  scoped_ptr<base::Timer> timer_;
+
+  // Manages the decoder and process generated video packets.
+  scoped_ptr<TestVideoRenderer> test_video_renderer_;
+
+  // Used to encode desktop frames to generate video packets.
+  scoped_ptr<VideoEncoder> encoder_;
+
+ private:
+  // testing::Test interface.
+  void SetUp() override;
+
+  // return the mean error of two frames.
+  double CalculateError(const webrtc::DesktopFrame* original_frame,
+                        const webrtc::DesktopFrame* decoded_frame) const;
+
+  // Fill a desktop frame with a gradient.
+  void FillFrameWithGradient(webrtc::DesktopFrame* frame) const;
+
+  // The thread's message loop. Valid only when the thread is alive.
+  scoped_ptr<base::MessageLoop> message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestVideoRendererTest);
+};
+
+TestVideoRendererTest::TestVideoRendererTest()
+    : timer_(new base::Timer(true, false)) {}
+
+TestVideoRendererTest::~TestVideoRendererTest() {}
+
+void TestVideoRendererTest::SetUp() {
+  if (!base::MessageLoop::current()) {
+    // Create a temporary message loop if the current thread does not already
+    // have one.
+    message_loop_.reset(new base::MessageLoop);
+  }
+  test_video_renderer_.reset(new TestVideoRenderer());
+}
+
+void TestVideoRendererTest::TestVideoPacketProcessing(int screen_width,
+                                                      int screen_height,
+                                                      double error_limit) {
+  DCHECK(encoder_);
+  DCHECK(test_video_renderer_);
+
+  scoped_ptr<webrtc::DesktopFrame> original_frame =
+      CreateDesktopFrameWithGradient(screen_width, screen_height);
+  EXPECT_TRUE(original_frame);
+  scoped_ptr<VideoPacket> packet = encoder_->Encode(*original_frame.get());
+  DCHECK(!run_loop_ || !run_loop_->running());
+  run_loop_.reset(new base::RunLoop());
+
+  // Wait for the video packet to be processed and rendered to buffer.
+  test_video_renderer_->ProcessVideoPacket(packet.Pass(),
+                                           run_loop_->QuitClosure());
+  run_loop_->Run();
+
+  scoped_ptr<webrtc::DesktopFrame> buffer_copy =
+      test_video_renderer_->GetBufferForTest();
+  EXPECT_NE(buffer_copy, nullptr);
+  double error = CalculateError(original_frame.get(), buffer_copy.get());
+  EXPECT_LT(error, error_limit);
+}
+
+double TestVideoRendererTest::CalculateError(
+    const webrtc::DesktopFrame* original_frame,
+    const webrtc::DesktopFrame* decoded_frame) const {
+  DCHECK(original_frame);
+  DCHECK(decoded_frame);
+
+  // Check size remains the same after encoding and decoding.
+  EXPECT_EQ(original_frame->size().width(), decoded_frame->size().width());
+  EXPECT_EQ(original_frame->size().height(), decoded_frame->size().height());
+  EXPECT_EQ(original_frame->stride(), decoded_frame->stride());
+  int screen_width = original_frame->size().width();
+  int screen_height = original_frame->size().height();
+
+  // Error is calculated as the sum of the square error at each pixel in the
+  // R, G and B components, each normalized to [0, 1].
+  double error_sum_squares = 0.0;
+
+  // The mapping between the position of a pixel on 3-dimensional image
+  // (origin at top left corner) and its position in 1-dimensional buffer.
+  //
+  //  _______________
+  // |      |        |      stride = 4 * width;
+  // |      |        |
+  // |      | height |      height * stride + width + 0; Red channel.
+  // |      |        |  =>  height * stride + width + 1; Green channel.
+  // |-------        |      height * stride + width + 2; Blue channel.
+  // | width         |
+  // |_______________|
+  //
+  for (int height = 0; height < screen_height; ++height) {
+    uint8_t* original_ptr = original_frame->data() +
+                            height * original_frame->stride();
+    uint8_t* decoded_ptr = decoded_frame->data() +
+                           height * decoded_frame->stride();
+
+    for (int width = 0; width < screen_width; ++width) {
+      // Errors are calculated in the R, G, B components.
+      for (int j = 0; j < 3; ++j) {
+        int offset = kBytesPerPixel * width + j;
+        double original_value = static_cast<double>(*(original_ptr + offset));
+        double decoded_value = static_cast<double>(*(decoded_ptr + offset));
+        double error = original_value - decoded_value;
+
+        // Normalize the error to [0, 1].
+        error /= 255.0;
+        error_sum_squares += error * error;
+      }
+    }
+  }
+  return sqrt(error_sum_squares / (3 * screen_width * screen_height));
+}
+
+scoped_ptr<webrtc::DesktopFrame>
+    TestVideoRendererTest::CreateDesktopFrameWithGradient(
+        int screen_width, int screen_height) const {
+  webrtc::DesktopSize screen_size(screen_width, screen_height);
+  scoped_ptr<webrtc::DesktopFrame> frame(
+      new webrtc::BasicDesktopFrame(screen_size));
+  frame->mutable_updated_region()->SetRect(
+      webrtc::DesktopRect::MakeSize(screen_size));
+  FillFrameWithGradient(frame.get());
+  return frame.Pass();
+}
+
+void TestVideoRendererTest::FillFrameWithGradient(
+    webrtc::DesktopFrame* frame) const {
+  for (int y = 0; y < frame->size().height(); ++y) {
+    uint8* p = frame->data() + y * frame->stride();
+    for (int x = 0; x < frame->size().width(); ++x) {
+      *p++ = (255.0 * x) / frame->size().width();
+      *p++ = (164.0 * y) / frame->size().height();
+      *p++ = (82.0 * (x + y)) /
+          (frame->size().width() + frame->size().height());
+      *p++ = 0;
+    }
+  }
+}
+
+// Verify video decoding for VP8 Codec.
+TEST_F(TestVideoRendererTest, VerifyVideoDecodingForVP8) {
+  encoder_ = VideoEncoderVpx::CreateForVP8();
+  test_video_renderer_->SetCodecForDecoding(
+      protocol::ChannelConfig::CODEC_VP8);
+  TestVideoPacketProcessing(kDefaultScreenWidth, kDefaultScreenHeight,
+                            kDefaultErrorLimit);
+}
+
+// Verify video decoding for VP9 Codec.
+TEST_F(TestVideoRendererTest, VerifyVideoDecodingForVP9) {
+  encoder_ = VideoEncoderVpx::CreateForVP9();
+  test_video_renderer_->SetCodecForDecoding(
+      protocol::ChannelConfig::CODEC_VP9);
+  TestVideoPacketProcessing(kDefaultScreenWidth, kDefaultScreenHeight,
+                            kDefaultErrorLimit);
+}
+
+
+// Verify video decoding for VERBATIM Codec.
+TEST_F(TestVideoRendererTest, VerifyVideoDecodingForVERBATIM) {
+  encoder_.reset(new VideoEncoderVerbatim());
+  test_video_renderer_->SetCodecForDecoding(
+      protocol::ChannelConfig::CODEC_VERBATIM);
+  TestVideoPacketProcessing(kDefaultScreenWidth, kDefaultScreenHeight,
+                            kDefaultErrorLimit);
+}
+
+// Verify a set of video packets are processed correctly.
+TEST_F(TestVideoRendererTest, VerifyMultipleVideoProcessing) {
+  encoder_ = VideoEncoderVpx::CreateForVP8();
+  test_video_renderer_->SetCodecForDecoding(
+      protocol::ChannelConfig::CODEC_VP8);
+
+  // Post multiple tasks to |test_video_renderer_|, and it should not crash.
+  // 20 is chosen because it's large enough to make sure that there will be
+  // more than one task on the video decode thread, while not too large to wait
+  // for too long for the unit test to complete.
+  const int task_num = 20;
+  ScopedVector<VideoPacket> video_packets;
+  for (int i = 0; i < task_num; ++i) {
+    scoped_ptr<webrtc::DesktopFrame> original_frame =
+        CreateDesktopFrameWithGradient(kDefaultScreenWidth,
+                                       kDefaultScreenHeight);
+    video_packets.push_back(encoder_->Encode(*original_frame.get()));
+  }
+
+  for (int i = 0; i < task_num; ++i) {
+    // Transfer ownership of video packet.
+    VideoPacket* packet = video_packets[i];
+    video_packets[i] = nullptr;
+    test_video_renderer_->ProcessVideoPacket(make_scoped_ptr(packet),
+                                             base::Bind(&base::DoNothing));
+  }
+}
+
+// Verify video packet size change is handled properly.
+TEST_F(TestVideoRendererTest, VerifyVideoPacketSizeChange) {
+  encoder_ = VideoEncoderVpx::CreateForVP8();
+  test_video_renderer_->SetCodecForDecoding(
+      protocol::ChannelConfig::Codec::CODEC_VP8);
+
+  TestVideoPacketProcessing(kDefaultScreenWidth, kDefaultScreenHeight,
+                            kDefaultErrorLimit);
+
+  TestVideoPacketProcessing(2 * kDefaultScreenWidth, 2 * kDefaultScreenHeight,
+                            kDefaultErrorLimit);
+
+  TestVideoPacketProcessing(kDefaultScreenWidth / 2, kDefaultScreenHeight / 2,
+                            kDefaultErrorLimit);
+}
+
+}  // namespace test
+}  // namespace remoting