Implement timing frames.

webrtc/modules/video_coding/generic_encoder_unittest.cc

+/*
+ *  Copyright (c) 2017 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 <vector>
+
+#include "webrtc/modules/video_coding/encoded_frame.h"
+#include "webrtc/modules/video_coding/generic_encoder.h"
+#include "webrtc/modules/video_coding/include/video_coding_defines.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+namespace test {
+namespace {
+inline size_t FrameSize(const size_t& min_frame_size,
+                        const size_t& max_frame_size,
+                        const int& s,
+                        const int& i) {
+  return min_frame_size + (s + 1) * i % (max_frame_size - min_frame_size);
+}
+
+class FakeEncodedImageCallback : public EncodedImageCallback {
+ public:
+  FakeEncodedImageCallback() : last_frame_was_timing_(false) {}
+  Result OnEncodedImage(const EncodedImage& encoded_image,
+                        const CodecSpecificInfo* codec_specific_info,
+                        const RTPFragmentationHeader* fragmentation) override {
+    last_frame_was_timing_ = encoded_image.timing_.is_timing_frame;
+    return Result::OK;
+  };
+
+  bool WasTimingFrame() { return last_frame_was_timing_; }
+
+ private:
+  bool last_frame_was_timing_;
+};
+
+enum class FrameType {
+  kNormal,
+  kTiming,
+  kDropped,
+};
+
+// Emulates |num_frames| on |num_streams| frames with capture timestamps
+// increased by 1 from 0. Size of each frame is between
+// |min_frame_size| and |max_frame_size|, outliers are counted relatevely to
+// |average_frame_sizes[]| for each stream.
+std::vector<std::vector<FrameType>> GetTimingFrames(
+    const int64_t delay_ms,
+    const size_t min_frame_size,
+    const size_t max_frame_size,
+    std::vector<size_t> average_frame_sizes,
+    const int num_streams,
+    const int num_frames) {
+  FakeEncodedImageCallback sink;
+  VCMEncodedFrameCallback callback(&sink, nullptr);
+  const size_t kFramerate = 30;
+  callback.SetTimingFramesThresholds(
+      {delay_ms, kDefaultOutlierFrameSizePercent});
+  callback.OnFrameRateChanged(kFramerate);
+  int s, i;
+  std::vector<std::vector<FrameType>> result(num_streams);
+  for (s = 0; s < num_streams; ++s)
+    callback.OnTargetBitrateChanged(average_frame_sizes[s] * kFramerate, s);
+  int64_t current_timestamp = 0;
+  for (i = 0; i < num_frames; ++i) {
+    current_timestamp += 1;
+    for (s = 0; s < num_streams; ++s) {
+      // every (5+s)-th frame is dropped on s-th stream by design.
+      bool dropped = i % (5 + s) == 0;
+
+      EncodedImage image;
+      CodecSpecificInfo codec_specific;
+      image._length = FrameSize(min_frame_size, max_frame_size, s, i);
+      image.capture_time_ms_ = current_timestamp;
+      codec_specific.codecType = kVideoCodecGeneric;
+      codec_specific.codecSpecific.generic.simulcast_idx = s;
+      callback.OnEncodeStarted(current_timestamp, s);
+      if (dropped) {
+        result[s].push_back(FrameType::kDropped);
+        continue;
+      }
+      callback.OnEncodedImage(image, &codec_specific, nullptr);
+      if (sink.WasTimingFrame()) {
+        result[s].push_back(FrameType::kTiming);
+      } else {
+        result[s].push_back(FrameType::kNormal);
+      }
+    }
+  }
+  return result;
+}
+}  // namespace
+
+TEST(TestVCMEncodedFrameCallback, MarksTimingFramesPeriodicallyTogether) {
+  const int64_t kDelayMs = 29;
+  const size_t kMinFrameSize = 10;
+  const size_t kMaxFrameSize = 20;
+  const int kNumFrames = 1000;
+  const int kNumStreams = 3;
+  // No outliers as 1000 is larger than anything from range [10,20].
+  const std::vector<size_t> kAverageSize = {1000, 1000, 1000};
+  auto frames = GetTimingFrames(kDelayMs, kMinFrameSize, kMaxFrameSize,
+                                kAverageSize, kNumStreams, kNumFrames);
+  // Timing frames should be tirggered every delayMs.
+  // As no outliers are expected, frames on all streams have to be
+  // marked together.
+  int last_timing_frame = -1;
+  for (int i = 0; i < kNumFrames; ++i) {
+    int num_normal = 0;
+    int num_timing = 0;
+    int num_dropped = 0;
+    for (int s = 0; s < kNumStreams; ++s) {
+      if (frames[s][i] == FrameType::kTiming) {
+        ++num_timing;
+      } else if (frames[s][i] == FrameType::kNormal) {
+        ++num_normal;
+      } else {
+        ++num_dropped;
+      }
+    }
+    // Can't have both normal and timing frames at the same timstamp.
+    EXPECT_TRUE(num_timing == 0 || num_normal == 0);
+    if (num_dropped < kNumStreams) {
+      if (last_timing_frame == -1 || i >= last_timing_frame + kDelayMs) {
+        // If didn't have timing frames for a period, current sent frame has to
+        // be one. No normal frames should be sent.
+        EXPECT_EQ(num_normal, 0);
+      } else {
+        // No unneeded timing frames should be sent.
+        EXPECT_EQ(num_timing, 0);
+      }
+    }
+    if (num_timing > 0)
+      last_timing_frame = i;
+  }
+}
+
+TEST(TestVCMEncodedFrameCallback, MarksOutliers) {
+  const int64_t kDelayMs = 29;
+  const size_t kMinFrameSize = 2495;
+  const size_t kMaxFrameSize = 2505;
+  const int kNumFrames = 1000;
+  const int kNumStreams = 3;
+  // Possible outliers as 1000 lies in range [995, 1005].
+  const std::vector<size_t> kAverageSize = {998, 1000, 1004};
+  auto frames = GetTimingFrames(kDelayMs, kMinFrameSize, kMaxFrameSize,
+                                kAverageSize, kNumStreams, kNumFrames);
+  // All outliers should be marked.
+  for (int i = 0; i < kNumFrames; ++i) {
+    for (int s = 0; s < kNumStreams; ++s) {
+      if (FrameSize(kMinFrameSize, kMaxFrameSize, s, i) >=
+          kAverageSize[s] * kDefaultOutlierFrameSizePercent / 100) {
+        // Too big frame. May be dropped or timing, but not normal.
+        EXPECT_NE(frames[s][i], FrameType::kNormal);
+      }
+    }
+  }
+}
+
+}  // namespace test
+}  // namespace webrtc