PacketBuffer is now ref counted.

webrtc/modules/video_coding/rtp_frame_reference_finder_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 <cstring>
+#include <limits>
+#include <map>
+#include <set>
+#include <utility>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/random.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/modules/video_coding/frame_object.h"
+#include "webrtc/modules/video_coding/packet_buffer.h"
+#include "webrtc/system_wrappers/include/clock.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class FakePacketBuffer : public PacketBuffer {
+ public:
+  FakePacketBuffer() : PacketBuffer(nullptr, 0, 0, nullptr) {}
+
+  VCMPacket* GetPacket(uint16_t seq_num) override {
+    auto packet_it = packets_.find(seq_num);
+    return packet_it == packets_.end() ? nullptr : &packet_it->second;
+  }
+
+  bool InsertPacket(const VCMPacket& packet) override {
+    packets_[packet.seqNum] = packet;
+    return true;
+  }
+
+  bool GetBitstream(const RtpFrameObject& frame,
+                    uint8_t* destination) override {
+    return true;
+  }
+
+  void ReturnFrame(RtpFrameObject* frame) override {
+    packets_.erase(frame->first_seq_num());
+  }
+
+ private:
+  std::map<uint16_t, VCMPacket> packets_;
+};
+
+class TestRtpFrameReferenceFinder : public ::testing::Test,
+                                    public OnCompleteFrameCallback {
+ protected:
+  TestRtpFrameReferenceFinder()
+      : rand_(0x8739211),
+        ref_packet_buffer_(new FakePacketBuffer()),
+        reference_finder_(new RtpFrameReferenceFinder(this)),
+        frames_from_callback_(FrameComp()) {}
+
+  uint16_t Rand() { return rand_.Rand(std::numeric_limits<uint16_t>::max()); }
+
+  void OnCompleteFrame(std::unique_ptr<FrameObject> frame) override {
+    uint16_t pid = frame->picture_id;
+    uint16_t sidx = frame->spatial_layer;
+    auto frame_it = frames_from_callback_.find(std::make_pair(pid, sidx));
+    if (frame_it != frames_from_callback_.end()) {
+      ADD_FAILURE() << "Already received frame with (pid:sidx): (" << pid << ":"
+                    << sidx << ")";
+      return;
+    }
+
+    frames_from_callback_.insert(
+        std::make_pair(std::make_pair(pid, sidx), std::move(frame)));
+  }
+
+  void InsertGeneric(uint16_t seq_num_start,
+                     uint16_t seq_num_end,
+                     bool keyframe) {
+    VCMPacket packet;
+    packet.codec = kVideoCodecGeneric;
+    packet.seqNum = seq_num_start;
+    packet.frameType = keyframe ? kVideoFrameKey : kVideoFrameDelta;
+
+    ref_packet_buffer_->InsertPacket(packet);
+    std::unique_ptr<RtpFrameObject> frame(new RtpFrameObject(
+        ref_packet_buffer_, seq_num_start, seq_num_end, 0, 0, 0));
+    reference_finder_->ManageFrame(std::move(frame));
+  }
+
+  void InsertVp8(uint16_t seq_num_start,
+                 uint16_t seq_num_end,
+                 bool keyframe,
+                 int32_t pid = kNoPictureId,
+                 uint8_t tid = kNoTemporalIdx,
+                 int32_t tl0 = kNoTl0PicIdx,
+                 bool sync = false) {
+    VCMPacket packet;
+    packet.codec = kVideoCodecVP8;
+    packet.seqNum = seq_num_start;
+    packet.frameType = keyframe ? kVideoFrameKey : kVideoFrameDelta;
+    packet.video_header.codecHeader.VP8.pictureId = pid % (1 << 15);
+    packet.video_header.codecHeader.VP8.temporalIdx = tid;
+    packet.video_header.codecHeader.VP8.tl0PicIdx = tl0;
+    packet.video_header.codecHeader.VP8.layerSync = sync;
+
+    ref_packet_buffer_->InsertPacket(packet);
+    std::unique_ptr<RtpFrameObject> frame(new RtpFrameObject(
+        ref_packet_buffer_, seq_num_start, seq_num_end, 0, 0, 0));
+    reference_finder_->ManageFrame(std::move(frame));
+  }
+
+  void InsertVp9Gof(uint16_t seq_num_start,
+                    uint16_t seq_num_end,
+                    bool keyframe,
+                    int32_t pid = kNoPictureId,
+                    uint8_t sid = kNoSpatialIdx,
+                    uint8_t tid = kNoTemporalIdx,
+                    int32_t tl0 = kNoTl0PicIdx,
+                    bool up_switch = false,
+                    GofInfoVP9* ss = nullptr) {
+    VCMPacket packet;
+    packet.codec = kVideoCodecVP9;
+    packet.seqNum = seq_num_start;
+    packet.frameType = keyframe ? kVideoFrameKey : kVideoFrameDelta;
+    packet.video_header.codecHeader.VP9.flexible_mode = false;
+    packet.video_header.codecHeader.VP9.picture_id = pid % (1 << 15);
+    packet.video_header.codecHeader.VP9.temporal_idx = tid;
+    packet.video_header.codecHeader.VP9.spatial_idx = sid;
+    packet.video_header.codecHeader.VP9.tl0_pic_idx = tl0;
+    packet.video_header.codecHeader.VP9.temporal_up_switch = up_switch;
+    if (ss != nullptr) {
+      packet.video_header.codecHeader.VP9.ss_data_available = true;
+      packet.video_header.codecHeader.VP9.gof = *ss;
+    }
+
+    ref_packet_buffer_->InsertPacket(packet);
+    std::unique_ptr<RtpFrameObject> frame(new RtpFrameObject(
+        ref_packet_buffer_, seq_num_start, seq_num_end, 0, 0, 0));
+    reference_finder_->ManageFrame(std::move(frame));
+  }
+
+  void InsertVp9Flex(uint16_t seq_num_start,
+                     uint16_t seq_num_end,
+                     bool keyframe,
+                     int32_t pid = kNoPictureId,
+                     uint8_t sid = kNoSpatialIdx,
+                     uint8_t tid = kNoTemporalIdx,
+                     int32_t tl0 = kNoTl0PicIdx,
+                     bool inter = false,
+                     std::vector<uint8_t> refs = std::vector<uint8_t>()) {
+    VCMPacket packet;
+    packet.codec = kVideoCodecVP9;
+    packet.seqNum = seq_num_start;
+    packet.frameType = keyframe ? kVideoFrameKey : kVideoFrameDelta;
+    packet.video_header.codecHeader.VP9.inter_layer_predicted = inter;
+    packet.video_header.codecHeader.VP9.flexible_mode = true;
+    packet.video_header.codecHeader.VP9.picture_id = pid % (1 << 15);
+    packet.video_header.codecHeader.VP9.temporal_idx = tid;
+    packet.video_header.codecHeader.VP9.spatial_idx = sid;
+    packet.video_header.codecHeader.VP9.tl0_pic_idx = tl0;
+    packet.video_header.codecHeader.VP9.num_ref_pics = refs.size();
+    for (size_t i = 0; i < refs.size(); ++i)
+      packet.video_header.codecHeader.VP9.pid_diff[i] = refs[i];
+
+    ref_packet_buffer_->InsertPacket(packet);
+    std::unique_ptr<RtpFrameObject> frame(new RtpFrameObject(
+        ref_packet_buffer_, seq_num_start, seq_num_end, 0, 0, 0));
+    reference_finder_->ManageFrame(std::move(frame));
+  }
+
+  // Check if a frame with picture id |pid| and spatial index |sidx| has been
+  // delivered from the packet buffer, and if so, if it has the references
+  // specified by |refs|.
+  template <typename... T>
+  void CheckReferences(uint16_t pid, uint16_t sidx, T... refs) const {
+    auto frame_it = frames_from_callback_.find(std::make_pair(pid, sidx));
+    if (frame_it == frames_from_callback_.end()) {
+      ADD_FAILURE() << "Could not find frame with (pid:sidx): (" << pid << ":"
+                    << sidx << ")";
+      return;
+    }
+
+    std::set<uint16_t> actual_refs;
+    for (uint8_t r = 0; r < frame_it->second->num_references; ++r) {
+      actual_refs.insert(frame_it->second->references[r]);
+    }
+
+    std::set<uint16_t> expected_refs;
+    RefsToSet(&expected_refs, refs...);
+
+    ASSERT_EQ(expected_refs, actual_refs);
+  }
+
+  template <typename... T>
+  void CheckReferencesGeneric(uint16_t pid, T... refs) const {
+    CheckReferences(pid, 0, refs...);
+  }
+
+  template <typename... T>
+  void CheckReferencesVp8(uint16_t pid, T... refs) const {
+    CheckReferences(pid, 0, refs...);
+  }
+
+  template <typename... T>
+  void CheckReferencesVp9(uint16_t pid, uint8_t sidx, T... refs) const {
+    CheckReferences(pid, sidx, refs...);
+  }
+
+  template <typename... T>
+  void RefsToSet(std::set<uint16_t>* m, uint16_t ref, T... refs) const {
+    m->insert(ref);
+    RefsToSet(m, refs...);
+  }
+
+  void RefsToSet(std::set<uint16_t>* m) const {}
+
+  Random rand_;
+  rtc::scoped_refptr<FakePacketBuffer> ref_packet_buffer_;
+  std::unique_ptr<RtpFrameReferenceFinder> reference_finder_;
+  struct FrameComp {
+    bool operator()(const std::pair<uint16_t, uint8_t> f1,
+                    const std::pair<uint16_t, uint8_t> f2) const {
+      if (f1.first == f2.first)
+        return f1.second < f2.second;
+      return f1.first < f2.first;
+    }
+  };
+  std::map<std::pair<uint16_t, uint8_t>,
+           std::unique_ptr<FrameObject>,
+           FrameComp>
+      frames_from_callback_;
+};
+
+TEST_F(TestRtpFrameReferenceFinder, PaddingPackets) {
+  uint16_t sn = Rand();
+
+  InsertGeneric(sn, sn, true);
+  InsertGeneric(sn + 2, sn + 2, false);
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+  reference_finder_->PaddingReceived(sn + 1);
+  EXPECT_EQ(2UL, frames_from_callback_.size());
+}
+
+TEST_F(TestRtpFrameReferenceFinder, PaddingPacketsReordered) {
+  uint16_t sn = Rand();
+
+  InsertGeneric(sn, sn, true);
+  reference_finder_->PaddingReceived(sn + 1);
+  reference_finder_->PaddingReceived(sn + 4);
+  InsertGeneric(sn + 2, sn + 3, false);
+
+  EXPECT_EQ(2UL, frames_from_callback_.size());
+  CheckReferencesGeneric(sn);
+  CheckReferencesGeneric(sn + 3, sn);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, PaddingPacketsReorderedMultipleKeyframes) {
+  uint16_t sn = Rand();
+
+  InsertGeneric(sn, sn, true);
+  reference_finder_->PaddingReceived(sn + 1);
+  reference_finder_->PaddingReceived(sn + 4);
+  InsertGeneric(sn + 2, sn + 3, false);
+  InsertGeneric(sn + 5, sn + 5, true);
+  reference_finder_->PaddingReceived(sn + 6);
+  reference_finder_->PaddingReceived(sn + 9);
+  InsertGeneric(sn + 7, sn + 8, false);
+
+  EXPECT_EQ(4UL, frames_from_callback_.size());
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp8NoPictureId) {
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn + 2, true);
+  ASSERT_EQ(1UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 3, sn + 4, false);
+  ASSERT_EQ(2UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 5, sn + 8, false);
+  ASSERT_EQ(3UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 9, sn + 9, false);
+  ASSERT_EQ(4UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 10, sn + 11, false);
+  ASSERT_EQ(5UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 12, sn + 12, true);
+  ASSERT_EQ(6UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 13, sn + 17, false);
+  ASSERT_EQ(7UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 18, sn + 18, false);
+  ASSERT_EQ(8UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 19, sn + 20, false);
+  ASSERT_EQ(9UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 21, sn + 21, false);
+
+  ASSERT_EQ(10UL, frames_from_callback_.size());
+  CheckReferencesVp8(sn + 2);
+  CheckReferencesVp8(sn + 4, sn + 2);
+  CheckReferencesVp8(sn + 8, sn + 4);
+  CheckReferencesVp8(sn + 9, sn + 8);
+  CheckReferencesVp8(sn + 11, sn + 9);
+  CheckReferencesVp8(sn + 12);
+  CheckReferencesVp8(sn + 17, sn + 12);
+  CheckReferencesVp8(sn + 18, sn + 17);
+  CheckReferencesVp8(sn + 20, sn + 18);
+  CheckReferencesVp8(sn + 21, sn + 20);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp8NoPictureIdReordered) {
+  uint16_t sn = 0xfffa;
+
+  InsertVp8(sn, sn + 2, true);
+  InsertVp8(sn + 3, sn + 4, false);
+  InsertVp8(sn + 5, sn + 8, false);
+  InsertVp8(sn + 9, sn + 9, false);
+  InsertVp8(sn + 10, sn + 11, false);
+  InsertVp8(sn + 12, sn + 12, true);
+  InsertVp8(sn + 13, sn + 17, false);
+  InsertVp8(sn + 18, sn + 18, false);
+  InsertVp8(sn + 19, sn + 20, false);
+  InsertVp8(sn + 21, sn + 21, false);
+
+  ASSERT_EQ(10UL, frames_from_callback_.size());
+  CheckReferencesVp8(sn + 2);
+  CheckReferencesVp8(sn + 4, sn + 2);
+  CheckReferencesVp8(sn + 8, sn + 4);
+  CheckReferencesVp8(sn + 9, sn + 8);
+  CheckReferencesVp8(sn + 11, sn + 9);
+  CheckReferencesVp8(sn + 12);
+  CheckReferencesVp8(sn + 17, sn + 12);
+  CheckReferencesVp8(sn + 18, sn + 17);
+  CheckReferencesVp8(sn + 20, sn + 18);
+  CheckReferencesVp8(sn + 21, sn + 20);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp8KeyFrameReferences) {
+  uint16_t sn = Rand();
+  InsertVp8(sn, sn, true);
+
+  ASSERT_EQ(1UL, frames_from_callback_.size());
+  CheckReferencesVp8(sn);
+}
+
+// Test with 1 temporal layer.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayers_0) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 1);
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 0, 2);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 0, 3);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 0, 4);
+
+  ASSERT_EQ(4UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid + 1);
+  CheckReferencesVp8(pid + 3, pid + 2);
+}
+
+// Test with 1 temporal layer.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayersReordering_0) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 1);
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 0, 2);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 0, 4);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 0, 3);
+  InsertVp8(sn + 5, sn + 5, false, pid + 5, 0, 6);
+  InsertVp8(sn + 6, sn + 6, false, pid + 6, 0, 7);
+  InsertVp8(sn + 4, sn + 4, false, pid + 4, 0, 5);
+
+  ASSERT_EQ(7UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid + 1);
+  CheckReferencesVp8(pid + 3, pid + 2);
+  CheckReferencesVp8(pid + 4, pid + 3);
+  CheckReferencesVp8(pid + 5, pid + 4);
+  CheckReferencesVp8(pid + 6, pid + 5);
+}
+
+// Test with 2 temporal layers in a 01 pattern.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayers_01) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 255);
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 1, 255, true);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 0, 0);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 1, 0);
+
+  ASSERT_EQ(4UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(pid + 3, pid + 1, pid + 2);
+}
+
+// Test with 2 temporal layers in a 01 pattern.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayersReordering_01) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 1, 255, true);
+  InsertVp8(sn, sn, true, pid, 0, 255);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 1, 0);
+  InsertVp8(sn + 5, sn + 5, false, pid + 5, 1, 1);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 0, 0);
+  InsertVp8(sn + 4, sn + 4, false, pid + 4, 0, 1);
+  InsertVp8(sn + 6, sn + 6, false, pid + 6, 0, 2);
+  InsertVp8(sn + 7, sn + 7, false, pid + 7, 1, 2);
+
+  ASSERT_EQ(8UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(pid + 3, pid + 1, pid + 2);
+  CheckReferencesVp8(pid + 4, pid + 2);
+  CheckReferencesVp8(pid + 5, pid + 3, pid + 4);
+  CheckReferencesVp8(pid + 6, pid + 4);
+  CheckReferencesVp8(pid + 7, pid + 5, pid + 6);
+}
+
+// Test with 3 temporal layers in a 0212 pattern.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayers_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 55);
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 2, 55, true);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 1, 55, true);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 2, 55);
+  InsertVp8(sn + 4, sn + 4, false, pid + 4, 0, 56);
+  InsertVp8(sn + 5, sn + 5, false, pid + 5, 2, 56);
+  InsertVp8(sn + 6, sn + 6, false, pid + 6, 1, 56);
+  InsertVp8(sn + 7, sn + 7, false, pid + 7, 2, 56);
+  InsertVp8(sn + 8, sn + 8, false, pid + 8, 0, 57);
+  InsertVp8(sn + 9, sn + 9, false, pid + 9, 2, 57, true);
+  InsertVp8(sn + 10, sn + 10, false, pid + 10, 1, 57, true);
+  InsertVp8(sn + 11, sn + 11, false, pid + 11, 2, 57);
+
+  ASSERT_EQ(12UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(pid + 3, pid, pid + 1, pid + 2);
+  CheckReferencesVp8(pid + 4, pid);
+  CheckReferencesVp8(pid + 5, pid + 2, pid + 3, pid + 4);
+  CheckReferencesVp8(pid + 6, pid + 2, pid + 4);
+  CheckReferencesVp8(pid + 7, pid + 4, pid + 5, pid + 6);
+  CheckReferencesVp8(pid + 8, pid + 4);
+  CheckReferencesVp8(pid + 9, pid + 8);
+  CheckReferencesVp8(pid + 10, pid + 8);
+  CheckReferencesVp8(pid + 11, pid + 8, pid + 9, pid + 10);
+}
+
+// Test with 3 temporal layers in a 0212 pattern.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayersMissingFrame_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 55, false);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 1, 55, true);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 2, 55, false);
+
+  ASSERT_EQ(2UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 2, pid);
+}
+
+// Test with 3 temporal layers in a 0212 pattern.
+TEST_F(TestRtpFrameReferenceFinder, Vp8TemporalLayersReordering_0212) {
+  uint16_t pid = 126;
+  uint16_t sn = Rand();
+
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 2, 55, true);
+  InsertVp8(sn, sn, true, pid, 0, 55, false);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 1, 55, true);
+  InsertVp8(sn + 4, sn + 4, false, pid + 4, 0, 56, false);
+  InsertVp8(sn + 5, sn + 5, false, pid + 5, 2, 56, false);
+  InsertVp8(sn + 3, sn + 3, false, pid + 3, 2, 55, false);
+  InsertVp8(sn + 7, sn + 7, false, pid + 7, 2, 56, false);
+  InsertVp8(sn + 9, sn + 9, false, pid + 9, 2, 57, true);
+  InsertVp8(sn + 6, sn + 6, false, pid + 6, 1, 56, false);
+  InsertVp8(sn + 8, sn + 8, false, pid + 8, 0, 57, false);
+  InsertVp8(sn + 11, sn + 11, false, pid + 11, 2, 57, false);
+  InsertVp8(sn + 10, sn + 10, false, pid + 10, 1, 57, true);
+
+  ASSERT_EQ(12UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(pid + 3, pid, pid + 1, pid + 2);
+  CheckReferencesVp8(pid + 4, pid);
+  CheckReferencesVp8(pid + 5, pid + 2, pid + 3, pid + 4);
+  CheckReferencesVp8(pid + 6, pid + 2, pid + 4);
+  CheckReferencesVp8(pid + 7, pid + 4, pid + 5, pid + 6);
+  CheckReferencesVp8(pid + 8, pid + 4);
+  CheckReferencesVp8(pid + 9, pid + 8);
+  CheckReferencesVp8(pid + 10, pid + 8);
+  CheckReferencesVp8(pid + 11, pid + 8, pid + 9, pid + 10);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp8InsertManyFrames_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  const int keyframes_to_insert = 50;
+  const int frames_per_keyframe = 120;  // Should be a multiple of 4.
+  uint8_t tl0 = 128;
+
+  for (int k = 0; k < keyframes_to_insert; ++k) {
+    InsertVp8(sn, sn, true, pid, 0, tl0, false);
+    InsertVp8(sn + 1, sn + 1, false, pid + 1, 2, tl0, true);
+    InsertVp8(sn + 2, sn + 2, false, pid + 2, 1, tl0, true);
+    InsertVp8(sn + 3, sn + 3, false, pid + 3, 2, tl0, false);
+    CheckReferencesVp8(pid);
+    CheckReferencesVp8(pid + 1, pid);
+    CheckReferencesVp8(pid + 2, pid);
+    CheckReferencesVp8(pid + 3, pid, pid + 1, pid + 2);
+    frames_from_callback_.clear();
+    ++tl0;
+
+    for (int f = 4; f < frames_per_keyframe; f += 4) {
+      uint16_t sf = sn + f;
+      uint16_t pidf = pid + f;
+
+      InsertVp8(sf, sf, false, pidf, 0, tl0, false);
+      InsertVp8(sf + 1, sf + 1, false, pidf + 1, 2, tl0, false);
+      InsertVp8(sf + 2, sf + 2, false, pidf + 2, 1, tl0, false);
+      InsertVp8(sf + 3, sf + 3, false, pidf + 3, 2, tl0, false);
+      CheckReferencesVp8(pidf, pidf - 4);
+      CheckReferencesVp8(pidf + 1, pidf, pidf - 1, pidf - 2);
+      CheckReferencesVp8(pidf + 2, pidf, pidf - 2);
+      CheckReferencesVp8(pidf + 3, pidf, pidf + 1, pidf + 2);
+      frames_from_callback_.clear();
+      ++tl0;
+    }
+
+    pid += frames_per_keyframe;
+    sn += frames_per_keyframe;
+  }
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp8LayerSync) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp8(sn, sn, true, pid, 0, 0, false);
+  InsertVp8(sn + 1, sn + 1, false, pid + 1, 1, 0, true);
+  InsertVp8(sn + 2, sn + 2, false, pid + 2, 0, 1, false);
+  ASSERT_EQ(3UL, frames_from_callback_.size());
+
+  InsertVp8(sn + 4, sn + 4, false, pid + 4, 0, 2, false);
+  InsertVp8(sn + 5, sn + 5, false, pid + 5, 1, 2, true);
+  InsertVp8(sn + 6, sn + 6, false, pid + 6, 0, 3, false);
+  InsertVp8(sn + 7, sn + 7, false, pid + 7, 1, 3, false);
+
+  ASSERT_EQ(7UL, frames_from_callback_.size());
+  CheckReferencesVp8(pid);
+  CheckReferencesVp8(pid + 1, pid);
+  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(pid + 4, pid + 2);
+  CheckReferencesVp8(pid + 5, pid + 4);
+  CheckReferencesVp8(pid + 6, pid + 4);
+  CheckReferencesVp8(pid + 7, pid + 6, pid + 5);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofInsertOneFrame) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode1);
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+
+  CheckReferencesVp9(pid, 0);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9NoPictureIdReordered) {
+  uint16_t sn = 0xfffa;
+
+  InsertVp9Gof(sn, sn + 2, true);
+  InsertVp9Gof(sn + 3, sn + 4, false);
+  InsertVp9Gof(sn + 9, sn + 9, false);
+  InsertVp9Gof(sn + 5, sn + 8, false);
+  InsertVp9Gof(sn + 12, sn + 12, true);
+  InsertVp9Gof(sn + 10, sn + 11, false);
+  InsertVp9Gof(sn + 13, sn + 17, false);
+  InsertVp9Gof(sn + 19, sn + 20, false);
+  InsertVp9Gof(sn + 21, sn + 21, false);
+  InsertVp9Gof(sn + 18, sn + 18, false);
+
+  ASSERT_EQ(10UL, frames_from_callback_.size());
+  CheckReferencesVp9(sn + 2, 0);
+  CheckReferencesVp9(sn + 4, 0, sn + 2);
+  CheckReferencesVp9(sn + 8, 0, sn + 4);
+  CheckReferencesVp9(sn + 9, 0, sn + 8);
+  CheckReferencesVp9(sn + 11, 0, sn + 9);
+  CheckReferencesVp9(sn + 12, 0);
+  CheckReferencesVp9(sn + 17, 0, sn + 12);
+  CheckReferencesVp9(sn + 18, 0, sn + 17);
+  CheckReferencesVp9(sn + 20, 0, sn + 18);
+  CheckReferencesVp9(sn + 21, 0, sn + 20);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_0) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode1);  // Only 1 spatial layer.
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 0, 1, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 0, 2, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 0, 3, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 4, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 0, 5, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 0, 6, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 0, 7, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 8, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 0, 9, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 0, 10, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 0, 11, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 12, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 0, 13, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 0, 14, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 0, 15, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 16, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 0, 17, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 0, 18, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 0, 19, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid + 1);
+  CheckReferencesVp9(pid + 3, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 3);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 5);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 7);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 9);
+  CheckReferencesVp9(pid + 11, 0, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 11);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 13);
+  CheckReferencesVp9(pid + 15, 0, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 15);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 17);
+  CheckReferencesVp9(pid + 19, 0, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_0) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode1);  // Only 1 spatial layer.
+
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 0, 2, false);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 0, 1, false);
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 4, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 0, 3, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 0, 5, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 0, 7, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 0, 6, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 8, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 0, 10, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 0, 13, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 0, 11, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 0, 9, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 16, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 0, 14, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 0, 15, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 12, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 0, 17, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 0, 19, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 0, 18, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid + 1);
+  CheckReferencesVp9(pid + 3, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 3);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 5);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 7);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 9);
+  CheckReferencesVp9(pid + 11, 0, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 11);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 13);
+  CheckReferencesVp9(pid + 15, 0, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 15);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 17);
+  CheckReferencesVp9(pid + 19, 0, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofSkipFramesTemporalLayers_01) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode2);  // 0101 pattern
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 1, 0, false);
+  // Skip GOF with tl0 1
+  InsertVp9Gof(sn + 4, sn + 4, true, pid + 4, 0, 0, 2, false, &ss);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 1, 2, false);
+  // Skip GOF with tl0 3
+  // Skip GOF with tl0 4
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 0, 5, false, &ss);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 1, 5, false);
+
+  ASSERT_EQ(6UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 4, 0);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 10);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofSkipFramesTemporalLayers_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode3);  // 02120212 pattern
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 2, 0, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 1, 0, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 2, 0, false);
+
+  ASSERT_EQ(4UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 1, pid + 2);
+
+  // Skip frames with tl0 = 1
+
+  InsertVp9Gof(sn + 8, sn + 8, true, pid + 8, 0, 0, 2, false, &ss);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 2, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 2, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 2, false);
+
+  ASSERT_EQ(8UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid + 8, 0);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+
+  // Now insert frames with tl0 = 1
+  InsertVp9Gof(sn + 4, sn + 4, true, pid + 4, 0, 0, 1, false, &ss);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 1, false);
+
+  ASSERT_EQ(9UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid + 4, 0);
+
+  // Rest of frames belonging to tl0 = 1
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 1, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 1, true);  // up-switch
+
+  ASSERT_EQ(12UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_01) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode2);  // 0101 pattern
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 1, 0, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 0, 1, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 1, 1, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 2, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 1, 2, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 0, 3, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 1, 3, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 4, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 1, 4, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 0, 5, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 1, 5, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 6, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 1, 6, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 0, 7, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 1, 7, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 8, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 1, 8, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 0, 9, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 1, 9, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 2);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 6);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 10);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 14);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 16);
+  CheckReferencesVp9(pid + 19, 0, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_01) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode2);  // 01 pattern
+
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 1, 0, false);
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 0, 1, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 2, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 1, 1, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 1, 2, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 1, 3, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 0, 3, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 0, 5, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 4, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 1, 4, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 1, 5, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 1, 6, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 8, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 6, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 0, 7, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 1, 8, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 1, 9, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 1, 7, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 0, 9, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 2);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 6);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 10);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 14);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 16);
+  CheckReferencesVp9(pid + 19, 0, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode3);  // 0212 pattern
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 2, 0, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 1, 0, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 2, 0, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 1, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 1, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 1, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 1, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 2, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 2, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 2, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 2, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 3, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 2, 3, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 1, 3, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 2, 3, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 4, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 2, 4, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 1, 4, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 2, 4, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 5, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 4);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 8);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 13, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 12);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 16);
+  CheckReferencesVp9(pid + 19, 0, pid + 17, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode3);  // 0212 pattern
+
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 1, 0, false);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 2, 0, false);
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 2, 0, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 1, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 1, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 1, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 2, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 1, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 2, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 2, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 2, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 2, 3, false);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 3, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 1, 3, false);
+  InsertVp9Gof(sn + 16, sn + 16, false, pid + 16, 0, 0, 4, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 2, 3, false);
+  InsertVp9Gof(sn + 17, sn + 17, false, pid + 17, 0, 2, 4, false);
+  InsertVp9Gof(sn + 19, sn + 19, false, pid + 19, 0, 2, 4, false);
+  InsertVp9Gof(sn + 18, sn + 18, false, pid + 18, 0, 1, 4, false);
+
+  ASSERT_EQ(20UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 5, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 4);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 8);
+  CheckReferencesVp9(pid + 13, 0, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 13, pid + 14);
+  CheckReferencesVp9(pid + 16, 0, pid + 12);
+  CheckReferencesVp9(pid + 17, 0, pid + 16);
+  CheckReferencesVp9(pid + 18, 0, pid + 16);
+  CheckReferencesVp9(pid + 19, 0, pid + 17, pid + 18);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersUpSwitch_02120212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode4);  // 02120212 pattern
+
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 2, 0, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 1, 0, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 2, 0, false);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 1, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 1, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 1, true);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 1, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 2, true);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 2, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 2, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 2, true);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 3, false);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 2, 3, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 1, 3, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 2, 3, false);
+
+  ASSERT_EQ(16UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid);
+  CheckReferencesVp9(pid + 5, 0, pid + 3, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 2, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 4);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 8);
+  CheckReferencesVp9(pid + 13, 0, pid + 11, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 10, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 13, pid + 14);
+}
+
+TEST_F(TestRtpFrameReferenceFinder,
+       Vp9GofTemporalLayersUpSwitchReordered_02120212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode4);  // 02120212 pattern
+
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 2, 0, false);
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 1, false);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 1, 0, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 1, false);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 2, 0, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 1, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 2, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 1, true);
+  InsertVp9Gof(sn + 12, sn + 12, false, pid + 12, 0, 0, 3, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 2, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 2, true);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 2, true);
+  InsertVp9Gof(sn + 13, sn + 13, false, pid + 13, 0, 2, 3, false);
+  InsertVp9Gof(sn + 15, sn + 15, false, pid + 15, 0, 2, 3, false);
+  InsertVp9Gof(sn + 14, sn + 14, false, pid + 14, 0, 1, 3, false);
+
+  ASSERT_EQ(16UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid);
+  CheckReferencesVp9(pid + 5, 0, pid + 3, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 2, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 4);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+  CheckReferencesVp9(pid + 12, 0, pid + 8);
+  CheckReferencesVp9(pid + 13, 0, pid + 11, pid + 12);
+  CheckReferencesVp9(pid + 14, 0, pid + 10, pid + 12);
+  CheckReferencesVp9(pid + 15, 0, pid + 13, pid + 14);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_01_0212) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+  GofInfoVP9 ss;
+  ss.SetGofInfoVP9(kTemporalStructureMode2);  // 01 pattern
+
+  InsertVp9Gof(sn + 1, sn + 1, false, pid + 1, 0, 1, 0, false);
+  InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
+  InsertVp9Gof(sn + 3, sn + 3, false, pid + 3, 0, 1, 1, false);
+  InsertVp9Gof(sn + 6, sn + 6, false, pid + 6, 0, 1, 2, false);
+  ss.SetGofInfoVP9(kTemporalStructureMode3);  // 0212 pattern
+  InsertVp9Gof(sn + 4, sn + 4, false, pid + 4, 0, 0, 2, false, &ss);
+  InsertVp9Gof(sn + 2, sn + 2, false, pid + 2, 0, 0, 1, false);
+  InsertVp9Gof(sn + 5, sn + 5, false, pid + 5, 0, 2, 2, false);
+  InsertVp9Gof(sn + 8, sn + 8, false, pid + 8, 0, 0, 3, false);
+  InsertVp9Gof(sn + 10, sn + 10, false, pid + 10, 0, 1, 3, false);
+  InsertVp9Gof(sn + 7, sn + 7, false, pid + 7, 0, 2, 2, false);
+  InsertVp9Gof(sn + 11, sn + 11, false, pid + 11, 0, 2, 3, false);
+  InsertVp9Gof(sn + 9, sn + 9, false, pid + 9, 0, 2, 3, false);
+
+  ASSERT_EQ(12UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid + 1, 0, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 3, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid);
+  CheckReferencesVp9(pid + 5, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 7, 0, pid + 5, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 4);
+  CheckReferencesVp9(pid + 9, 0, pid + 8);
+  CheckReferencesVp9(pid + 10, 0, pid + 8);
+  CheckReferencesVp9(pid + 11, 0, pid + 9, pid + 10);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeOneFrame) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp9Flex(sn, sn, true, pid, 0, 0, 0, false);
+
+  ASSERT_EQ(1UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeTwoSpatialLayers) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp9Flex(sn, sn, true, pid, 0, 0, 0, false);
+  InsertVp9Flex(sn + 1, sn + 1, true, pid, 1, 0, 0, true);
+  InsertVp9Flex(sn + 2, sn + 2, false, pid + 1, 1, 0, 0, false, {1});
+  InsertVp9Flex(sn + 3, sn + 3, false, pid + 2, 0, 0, 1, false, {2});
+  InsertVp9Flex(sn + 4, sn + 4, false, pid + 2, 1, 0, 1, false, {1});
+  InsertVp9Flex(sn + 5, sn + 5, false, pid + 3, 1, 0, 1, false, {1});
+  InsertVp9Flex(sn + 6, sn + 6, false, pid + 4, 0, 0, 2, false, {2});
+  InsertVp9Flex(sn + 7, sn + 7, false, pid + 4, 1, 0, 2, false, {1});
+  InsertVp9Flex(sn + 8, sn + 8, false, pid + 5, 1, 0, 2, false, {1});
+  InsertVp9Flex(sn + 9, sn + 9, false, pid + 6, 0, 0, 3, false, {2});
+  InsertVp9Flex(sn + 10, sn + 10, false, pid + 6, 1, 0, 3, false, {1});
+  InsertVp9Flex(sn + 11, sn + 11, false, pid + 7, 1, 0, 3, false, {1});
+  InsertVp9Flex(sn + 12, sn + 12, false, pid + 8, 0, 0, 4, false, {2});
+  InsertVp9Flex(sn + 13, sn + 13, false, pid + 8, 1, 0, 4, false, {1});
+
+  ASSERT_EQ(14UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid, 1);
+  CheckReferencesVp9(pid + 1, 1, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 2, 1, pid + 1);
+  CheckReferencesVp9(pid + 3, 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 1, pid + 3);
+  CheckReferencesVp9(pid + 5, 1, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 1, pid + 5);
+  CheckReferencesVp9(pid + 7, 1, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 1, pid + 7);
+}
+
+TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeTwoSpatialLayersReordered) {
+  uint16_t pid = Rand();
+  uint16_t sn = Rand();
+
+  InsertVp9Flex(sn + 1, sn + 1, true, pid, 1, 0, 0, true);
+  InsertVp9Flex(sn + 2, sn + 2, false, pid + 1, 1, 0, 0, false, {1});
+  InsertVp9Flex(sn, sn, true, pid, 0, 0, 0, false);
+  InsertVp9Flex(sn + 4, sn + 4, false, pid + 2, 1, 0, 1, false, {1});
+  InsertVp9Flex(sn + 5, sn + 5, false, pid + 3, 1, 0, 1, false, {1});
+  InsertVp9Flex(sn + 3, sn + 3, false, pid + 2, 0, 0, 1, false, {2});
+  InsertVp9Flex(sn + 7, sn + 7, false, pid + 4, 1, 0, 2, false, {1});
+  InsertVp9Flex(sn + 6, sn + 6, false, pid + 4, 0, 0, 2, false, {2});
+  InsertVp9Flex(sn + 8, sn + 8, false, pid + 5, 1, 0, 2, false, {1});
+  InsertVp9Flex(sn + 9, sn + 9, false, pid + 6, 0, 0, 3, false, {2});
+  InsertVp9Flex(sn + 11, sn + 11, false, pid + 7, 1, 0, 3, false, {1});
+  InsertVp9Flex(sn + 10, sn + 10, false, pid + 6, 1, 0, 3, false, {1});
+  InsertVp9Flex(sn + 13, sn + 13, false, pid + 8, 1, 0, 4, false, {1});
+  InsertVp9Flex(sn + 12, sn + 12, false, pid + 8, 0, 0, 4, false, {2});
+
+  ASSERT_EQ(14UL, frames_from_callback_.size());
+  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(pid, 1);
+  CheckReferencesVp9(pid + 1, 1, pid);
+  CheckReferencesVp9(pid + 2, 0, pid);
+  CheckReferencesVp9(pid + 2, 1, pid + 1);
+  CheckReferencesVp9(pid + 3, 1, pid + 2);
+  CheckReferencesVp9(pid + 4, 0, pid + 2);
+  CheckReferencesVp9(pid + 4, 1, pid + 3);
+  CheckReferencesVp9(pid + 5, 1, pid + 4);
+  CheckReferencesVp9(pid + 6, 0, pid + 4);
+  CheckReferencesVp9(pid + 6, 1, pid + 5);
+  CheckReferencesVp9(pid + 7, 1, pid + 6);
+  CheckReferencesVp9(pid + 8, 0, pid + 6);
+  CheckReferencesVp9(pid + 8, 1, pid + 7);
+}
+
+}  // namespace video_coding
+}  // namespace webrtc