Add a new frame generator that cycles through randomly generated slides.

webrtc/test/frame_generator_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.
  */
 
@@ skipping 63 matching lines @@
     EXPECT_EQ(0, frame->ntp_time_ms());
     EXPECT_EQ(0, frame->render_time_ms());
     EXPECT_EQ(0u, frame->timestamp());
 
     // Mutate to something arbitrary non-zero.
     frame->set_ntp_time_ms(11);
     frame->set_timestamp_us(12);
     frame->set_timestamp(13);
   }
 
+  uint64_t Hash(VideoFrame* frame) {
+    // Generate a 64-bit hash from the frame's buffer.
+    uint64_t hash = 19;
+    rtc::scoped_refptr<I420BufferInterface> i420_buffer =
+        frame->video_frame_buffer()->ToI420();
+    const uint8_t* buffer = i420_buffer->DataY();
+    for (int i = 0; i < y_size; ++i) {
+      hash = (37 * hash) + buffer[i];
+    }
+    buffer = i420_buffer->DataU();
+    for (int i = 0; i < uv_size; ++i) {
+      hash = (37 * hash) + buffer[i];
+    }
+    buffer = i420_buffer->DataV();
+    for (int i = 0; i < uv_size; ++i) {
+      hash = (37 * hash) + buffer[i];
+    }
+    return hash;
+  }
+
   std::string two_frame_filename_;
   std::string one_frame_filename_;
   const int y_size = kFrameWidth * kFrameHeight;
   const int uv_size = ((kFrameHeight + 1) / 2) * ((kFrameWidth + 1) / 2);
 };
 
 TEST_F(FrameGeneratorTest, SingleFrameFile) {
   std::unique_ptr<FrameGenerator> generator(FrameGenerator::CreateFromYuvFile(
       std::vector<std::string>(1, one_frame_filename_), kFrameWidth,
       kFrameHeight, 1));
@@ skipping 44 matching lines @@
       files, kFrameWidth, kFrameHeight, kRepeatCount));
   for (int i = 0; i < kRepeatCount; ++i)
     CheckFrameAndMutate(generator->NextFrame(), 0, 0, 0);
   for (int i = 0; i < kRepeatCount; ++i)
     CheckFrameAndMutate(generator->NextFrame(), 127, 127, 127);
   for (int i = 0; i < kRepeatCount; ++i)
     CheckFrameAndMutate(generator->NextFrame(), 255, 255, 255);
   CheckFrameAndMutate(generator->NextFrame(), 0, 0, 0);
 }
 
+TEST_F(FrameGeneratorTest, SlideGenerator) {
+  const int kGenCount = 9;
+  const int kRepeatCount = 3;
+  std::unique_ptr<FrameGenerator> generator(
+      FrameGenerator::CreateSlideGenerator(
+          kFrameWidth, kFrameHeight, kRepeatCount));
+  uint64_t hashes[kGenCount];
+  for (int i = 0; i < kGenCount; ++i) {
+    hashes[i] = Hash(generator->NextFrame());
+  }
+  // Check that the buffer changes only every |kRepeatCount| frames.
+  for (int i = 1; i < kGenCount; ++i) {
+    if (i % kRepeatCount == 0) {
+      EXPECT_NE(hashes[i-1], hashes[i]);
+    } else {
+      EXPECT_EQ(hashes[i-1], hashes[i]);
+    }
+  }
+}
+
 }  // namespace test
 }  // namespace webrtc