Added image pattern comparison logic for test interface and fixture.

remoting/test/test_video_renderer.cc

 // 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/bind.h"
+#include "base/callback_helpers.h"
 #include "base/logging.h"
 #include "base/synchronization/lock.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/thread.h"
 #include "remoting/codec/video_decoder.h"
 #include "remoting/codec/video_decoder_verbatim.h"
 #include "remoting/codec/video_decoder_vpx.h"
 #include "remoting/proto/video.pb.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
 
+namespace {
+
+// Used to store a RGB color, and it can be converted to and from RGBA32.
+struct RGBValue {
+  RGBValue(int r, int g, int b) : red(r), green(g), blue(b) {}
+  int red;
+  int green;
+  int blue;
+};
+
+// Convert a RGBA32 to a RGBValue.
+RGBValue ConvertRGBA32Tovalue(uint32_t color) {

[joedow, 2015/07/13 16:27:51]

Why a uint32_t instead of an RGBA32 here?  I'm actually thinking that the RGBA32
typedef doesn't provide much value since you have the name struct above.  I'd be
consistent in its usage but wondering if you should just use uint32_t.

[liaoyuke, 2015/07/13 18:12:59]

Now I remember the reason why I use uint32_t here is that I declared RGBA32 in
remoting::test, and I don't want to use remoting::test::RGBA32, which is too
long. I think you are right, the typedef doesn't provide much value here, and
since I will also use uint32_t(RGBA32) elsewhere, maybe it's better to
consistently use uint32_t.

+  RGBValue rgb_value((color >> 16) & 0xFF, (color >> 8) & 0xFF, color & 0xFF);
+  return rgb_value;
+}
+
+// Used to account for frame resizing and lossy encoding error in percentage.
+const double kMaxColorError = 0.02;
+}  // namespace
+
 namespace remoting {
 namespace test {
 
 // Implements video decoding functionality.
 class TestVideoRenderer::Core {
  public:
   Core();
   ~Core();
 
   // Initializes the internal structures of the class.
   void Initialize();
 
   // Used to decode video packets.
   void ProcessVideoPacket(scoped_ptr<VideoPacket> packet,
                           const base::Closure& done);
 
   // Initialize a decoder to decode video packets.
   void SetCodecForDecoding(const protocol::ChannelConfig::Codec codec);
 
-  // Returns a copy of the current buffer.
-  scoped_ptr<webrtc::DesktopFrame> GetBufferForTest() const;
+  // Returns a copy of the current frame.
+  scoped_ptr<webrtc::DesktopFrame> GetCurrentFrameForTest() const;
 
   // Set expected image pattern for comparison and the callback will be called
   // when the pattern is matched.
   void SetImagePatternAndMatchedCallback(
       const webrtc::DesktopRect& expected_rect,
-      const RgbaColor& expected_color,
+      RGBA32 expected_avg_color,
       const base::Closure& image_pattern_matched_callback);
 
  private:
+  // Returns average color of pixels fall within |rect| on the current frame.
+  RGBValue CalculateAverageColorvalue(const webrtc::DesktopRect& rect) const;
+
+  // Compares |candidate_avg_value| to |expected_avg_color_|.
+  // Returns true if the root mean square of the errors in the R, G and B
+  // components does not exceed a given limit.
+  bool ExpectedColorIsMatched(const RGBValue& candidate_avg_value) const;
+
   // Used to ensure Core methods are called on the same thread.
   base::ThreadChecker thread_checker_;
 
   // Used to decode video packets.
   scoped_ptr<VideoDecoder> decoder_;
 
   // Updated region of the current desktop frame compared to previous one.
   webrtc::DesktopRegion updated_region_;
 
   // Screen size of the remote host.
   webrtc::DesktopSize screen_size_;
 
   // Used to post tasks back to main thread.
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
 
   // Used to store decoded video frame.
-  scoped_ptr<webrtc::DesktopFrame> buffer_;
+  scoped_ptr<webrtc::DesktopFrame> frame_;
 
-  // Protects access to |buffer_|.
+  // Protects access to |frame_|.
   mutable base::Lock lock_;
 
   // Used to store the expected image pattern.
   webrtc::DesktopRect expected_rect_;
-  RgbaColor expected_color_;
-
-  // Maintains accumulating image pattern.
-  webrtc::DesktopRect accumulating_rect_;
-  RgbaColor accumulating_color_;
+  RGBA32 expected_avg_color_;
 
   // Used to store the callback when expected pattern is matched.
   base::Closure image_pattern_matched_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Core);
 };
 
 TestVideoRenderer::Core::Core()
     : main_task_runner_(base::ThreadTaskRunnerHandle::Get()) {
   thread_checker_.DetachFromThread();
@@ skipping 31 matching lines @@
       decoder_.reset(new VideoDecoderVerbatim());
       break;
     }
     default: {
       NOTREACHED() << "Unsupported codec: " << codec;
     }
   }
 }
 
 scoped_ptr<webrtc::DesktopFrame>
-    TestVideoRenderer::Core::GetBufferForTest() const {
+TestVideoRenderer::Core::GetCurrentFrameForTest() const {
   base::AutoLock auto_lock(lock_);
-  DCHECK(buffer_);
-  return make_scoped_ptr(webrtc::BasicDesktopFrame::CopyOf(*buffer_.get()));
+  DCHECK(frame_);
+  return make_scoped_ptr(webrtc::BasicDesktopFrame::CopyOf(*frame_.get()));
 }
 
 void TestVideoRenderer::Core::ProcessVideoPacket(
     scoped_ptr<VideoPacket> packet, const base::Closure& done) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(decoder_);
   DCHECK(packet);
 
   VLOG(2) << "TestVideoRenderer::Core::ProcessVideoPacket() Called";
 
   // Screen size is attached on the first packet as well as when the
   // host screen is resized.
   if (packet->format().has_screen_width() &&
       packet->format().has_screen_height()) {
     webrtc::DesktopSize source_size(packet->format().screen_width(),
                                     packet->format().screen_height());
     if (!screen_size_.equals(source_size)) {
       screen_size_ = source_size;
       decoder_->Initialize(screen_size_);
-      buffer_.reset(new webrtc::BasicDesktopFrame(screen_size_));
+      frame_.reset(new webrtc::BasicDesktopFrame(screen_size_));
     }
   }
 
   // To make life easier, assume that the desktop shape is a single rectangle.
   packet->clear_use_desktop_shape();
   if (!decoder_->DecodePacket(*packet.get())) {
     LOG(ERROR) << "Decoder::DecodePacket() failed.";
     return;
   }
 
   {
     base::AutoLock auto_lock(lock_);
 
     // Render the decoded packet and write results to the buffer.
     // Note that the |updated_region_| maintains the changed regions compared to
     // previous video frame.
     decoder_->RenderFrame(screen_size_,
                           webrtc::DesktopRect::MakeWH(screen_size_.width(),
-                          screen_size_.height()), buffer_->data(),
-                          buffer_->stride(), &updated_region_);
+                                                      screen_size_.height()),
+                          frame_->data(), frame_->stride(), &updated_region_);
   }
 
   main_task_runner_->PostTask(FROM_HERE, done);
 
-  // TODO(liaoyuke): Update |accumulating_rect_| and |accumulating_color_|, then
-  // compare to the expected image pattern to check whether the pattern is
-  // matched or not and update |image_pattern_matched| accordingly.
+  // Check to see if a image pattern matched reply is passed in, and whether
+  // the |expected_rect_| falls within the current frame.
+  if (image_pattern_matched_callback_.is_null() ||
+      expected_rect_.right() > frame_->size().width() ||
+      expected_rect_.bottom() > frame_->size().height()) {
+    return;
+  }
+
+  // Compare the expected image pattern with the corresponding rectangle region
+  // on the current frame.
+  RGBValue accumulating_avg_value = CalculateAverageColorvalue(expected_rect_);
+  VLOG(2) << accumulating_avg_value.red << " " << accumulating_avg_value.green
+          << " " << accumulating_avg_value.blue;
+
+  if (ExpectedColorIsMatched(accumulating_avg_value)) {
+    main_task_runner_->PostTask(
+        FROM_HERE, base::ResetAndReturn(&image_pattern_matched_callback_));
+  }
 }
 
 void TestVideoRenderer::Core::SetImagePatternAndMatchedCallback(
     const webrtc::DesktopRect& expected_rect,
-    const RgbaColor& expected_color,
+    RGBA32 expected_avg_color,
     const base::Closure& image_pattern_matched_callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   expected_rect_ = expected_rect;
-  expected_color_ = expected_color;
+  expected_avg_color_ = expected_avg_color;
   image_pattern_matched_callback_ = image_pattern_matched_callback;
 }
 
+RGBValue TestVideoRenderer::Core::CalculateAverageColorvalue(
+    const webrtc::DesktopRect& rect) const {
+  int red_sum = 0;
+  int green_sum = 0;
+  int blue_sum = 0;
+
+  // Loop through pixels that fall within |accumulating_rect_| to obtain the
+  // average color value.
+  for (int y = rect.top(); y < rect.bottom(); ++y) {
+    uint8_t* frame_pos =
+        frame_->data() + (y * frame_->stride() +
+                          rect.left() * webrtc::DesktopFrame::kBytesPerPixel);
+
+    // Pixels of decoded video frame are presented in ARGB format.
+    for (int x = 0; x < rect.width(); ++x) {
+      red_sum += frame_pos[2];
+      green_sum += frame_pos[1];
+      blue_sum += frame_pos[0];
+      frame_pos += 4;
+    }
+  }
+
+  int area = rect.width() * rect.height();
+  RGBValue rgb_value(red_sum / area, green_sum / area, blue_sum / area);
+  return rgb_value;
+}
+
+bool TestVideoRenderer::Core::ExpectedColorIsMatched(
+    const RGBValue& candidate_avg_value) const {
+  RGBValue expected_avg_value = ConvertRGBA32Tovalue(expected_avg_color_);
+  double error_sum_squares = 0;
+  double red_error = expected_avg_value.red - candidate_avg_value.red;
+  double green_error = expected_avg_value.green - candidate_avg_value.green;
+  double blue_error = expected_avg_value.blue - candidate_avg_value.blue;
+  error_sum_squares = red_error * red_error + green_error * green_error +
+                      blue_error * blue_error;
+  error_sum_squares /= (255.0 * 255.0);
+
+  return sqrt(error_sum_squares / 3) < kMaxColorError;
+}
+
 TestVideoRenderer::TestVideoRenderer()
     : video_decode_thread_(
         new base::Thread("TestVideoRendererVideoDecodingThread")),
       weak_factory_(this) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   core_.reset(new Core());
   if (!video_decode_thread_->Start()) {
     LOG(ERROR) << "Cannot start TestVideoRenderer";
   } else {
@@ skipping 59 matching lines @@
     const protocol::ChannelConfig::Codec codec) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   VLOG(2) << "TestVideoRenderer::SetDecoder() Called";
   video_decode_task_runner_->PostTask(
       FROM_HERE, base::Bind(&Core::SetCodecForDecoding,
                             base::Unretained(core_.get()),
                             codec));
 }
 
-scoped_ptr<webrtc::DesktopFrame> TestVideoRenderer::GetBufferForTest() const {
+scoped_ptr<webrtc::DesktopFrame> TestVideoRenderer::GetCurrentFrameForTest()
+    const {
   DCHECK(thread_checker_.CalledOnValidThread());
 
-  return core_->GetBufferForTest();
+  return core_->GetCurrentFrameForTest();
 }
 
 void TestVideoRenderer::SetImagePatternAndMatchedCallback(
     const webrtc::DesktopRect& expected_rect,
-    const RgbaColor& expected_color,
+    RGBA32 expected_avg_color,
     const base::Closure& image_pattern_matched_callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!expected_rect.is_empty()) << "Expected rect cannot be empty";
 
   DVLOG(2) << "TestVideoRenderer::SetImagePatternAndMatchedCallback() Called";
   video_decode_task_runner_->PostTask(
-      FROM_HERE, base::Bind(&Core::SetImagePatternAndMatchedCallback,
-                            base::Unretained(core_.get()), expected_rect,
-                            expected_color, image_pattern_matched_callback));
+      FROM_HERE,
+      base::Bind(&Core::SetImagePatternAndMatchedCallback,
+                 base::Unretained(core_.get()), expected_rect,
+                 expected_avg_color, image_pattern_matched_callback));
 }
 
 }  // namespace test
 }  // namespace remoting