Split IncomingVideoStream into two implementations, with smoothing and without.

webrtc/common_video/incoming_video_stream_unittest.cc

+/*
+ *  Copyright (c) 2016 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 "webrtc/base/event.h"
+#include "webrtc/common_video/include/incoming_video_stream.h"
+#include "webrtc/media/base/videosinkinterface.h"
+#include "webrtc/video_frame.h"
+
+namespace webrtc {
+
+// Basic test that checks if the no-smoothing implementation delivers a frame.
+TEST(IncomingVideoStreamTest, NoSmoothingOneFrame) {
+  class TestCallback : public rtc::VideoSinkInterface<VideoFrame> {
+   public:
+    TestCallback() : event_(false, false) {}
+    ~TestCallback() override {}
+
+    bool WaitForFrame(int milliseconds) { return event_.Wait(milliseconds); }
+
+   private:
+    void OnFrame(const VideoFrame& frame) override {
+      event_.Set();
+    }
+
+    rtc::Event event_;
+  } callback;
+  IncomingVideoStreamNoSmoothing stream(&callback);
+
+  rtc::VideoSinkInterface<VideoFrame>* stream_sink = &stream;
+  stream_sink->OnFrame(VideoFrame());
+
+  EXPECT_TRUE(callback.WaitForFrame(500));
+}
+
+// Tests that if the renderer is too slow, that frames will be dropped and
+// the "producer thread" (main test thread), will not be blocked from delivering
+// frames.
+TEST(IncomingVideoStreamTest, NoSmoothingTooManyFrames) {
+  class TestCallback : public rtc::VideoSinkInterface<VideoFrame> {
+   public:
+    TestCallback() : event_(false, false) {}
+    ~TestCallback() override {}
+
+    void Continue() { event_.Set(); }
+    int frame_count() const { return frame_count_; }
+
+   private:
+    void OnFrame(const VideoFrame& frame) override {
+      ++frame_count_;
+      if (frame_count_ == 1) {
+        // Block delivery of frames until we're allowed to continue.
+        event_.Wait(rtc::Event::kForever);
+      }
+    }
+
+    rtc::Event event_;
+    int frame_count_ = 0;
+  } callback;
+
+  {
+    IncomingVideoStreamNoSmoothing stream(&callback);
+
+    rtc::VideoSinkInterface<VideoFrame>* stream_sink = &stream;
+    for (int i = 0; i < 100; ++i)
+      stream_sink->OnFrame(VideoFrame());
+    // We need to set the 'continue' event before |stream| goes out of scope
+    // since we're currently blocking the queue (i.e. stream can't be deleted).
+    callback.Continue();
+  }
+
+  // Once |stream| has been deleted, we're guaranteed that no more calls to
+  // the OnFrame callback will be made, so we can safely check the frame count
+  // without having to worry about synchronization.
+
+  // In practice frame_count will be ~1.
+  EXPECT_LT(callback.frame_count(), 100);
+  EXPECT_GE(callback.frame_count(), 1);
+}
+
+}  // namespace webrtc