diff --git a/modules/video_coding/frame_buffer2.cc b/modules/video_coding/frame_buffer2.cc
index 7fcb728..f314ccb 100644
--- a/modules/video_coding/frame_buffer2.cc
+++ b/modules/video_coding/frame_buffer2.cc
@@ -249,7 +249,7 @@
 
 bool FrameBuffer::ValidReferences(const FrameObject& frame) const {
   for (size_t i = 0; i < frame.num_references; ++i) {
-    if (AheadOrAt(frame.references[i], frame.picture_id))
+    if (AheadOrAt<uint16_t>(frame.references[i], frame.picture_id))
       return false;
     for (size_t j = i + 1; j < frame.num_references; ++j) {
       if (frame.references[i] == frame.references[j])
diff --git a/modules/video_coding/frame_object.h b/modules/video_coding/frame_object.h
index 5299ed8..90c1c00 100644
--- a/modules/video_coding/frame_object.h
+++ b/modules/video_coding/frame_object.h
@@ -49,14 +49,14 @@
   // The tuple (|picture_id|, |spatial_layer|) uniquely identifies a frame
   // object. For codec types that don't necessarily have picture ids they
   // have to be constructed from the header data relevant to that codec.
-  uint16_t picture_id;
+  int64_t picture_id;
   uint8_t spatial_layer;
   uint32_t timestamp;
 
   // TODO(philipel): Add simple modify/access functions to prevent adding too
   // many |references|.
   size_t num_references;
-  uint16_t references[kMaxFrameReferences];
+  int64_t references[kMaxFrameReferences];
   bool inter_layer_predicted;
 };
 
diff --git a/modules/video_coding/rtp_frame_reference_finder.cc b/modules/video_coding/rtp_frame_reference_finder.cc
index 52947cb..e167e15 100644
--- a/modules/video_coding/rtp_frame_reference_finder.cc
+++ b/modules/video_coding/rtp_frame_reference_finder.cc
@@ -176,7 +176,7 @@
     if (last_unwrap_ == -1)
       last_unwrap_ = picture_id;
 
-    frame->picture_id = UnwrapPictureId(picture_id % kPicIdLength);
+    frame->picture_id = unwrapper_.Unwrap(picture_id);
     frame->num_references = frame->frame_type() == kVideoFrameKey ? 0 : 1;
     frame->references[0] = frame->picture_id - 1;
     return kHandOff;
@@ -228,22 +228,25 @@
   // picture id according to some incrementing counter.
   frame->picture_id = frame->last_seq_num();
   frame->num_references = frame->frame_type() == kVideoFrameDelta;
-  frame->references[0] = last_picture_id_gop;
-  if (AheadOf(frame->picture_id, last_picture_id_gop)) {
+  frame->references[0] = generic_unwrapper_.Unwrap(last_picture_id_gop);
+  if (AheadOf<uint16_t>(frame->picture_id, last_picture_id_gop)) {
     seq_num_it->second.first = frame->picture_id;
     seq_num_it->second.second = frame->picture_id;
   }
 
   last_picture_id_ = frame->picture_id;
   UpdateLastPictureIdWithPadding(frame->picture_id);
+  frame->picture_id = generic_unwrapper_.Unwrap(frame->picture_id);
   return kHandOff;
 }
 
 RtpFrameReferenceFinder::FrameDecision RtpFrameReferenceFinder::ManageFrameVp8(
     RtpFrameObject* frame) {
   rtc::Optional<RTPVideoTypeHeader> rtp_codec_header = frame->GetCodecHeader();
-  if (!rtp_codec_header)
+  if (!rtp_codec_header) {
+    LOG(LS_WARNING) << "Failed to get codec header from frame, dropping frame.";
     return kDrop;
+  }
 
   const RTPVideoHeaderVP8& codec_header = rtp_codec_header->VP8;
 
@@ -285,7 +288,7 @@
   if (frame->frame_type() == kVideoFrameKey) {
     frame->num_references = 0;
     layer_info_[codec_header.tl0PicIdx].fill(-1);
-    UpdateLayerInfoVp8(frame, codec_header);
+    UpdateLayerInfoVp8(frame);
     return kHandOff;
   }
 
@@ -307,7 +310,7 @@
             .first;
     frame->num_references = 1;
     frame->references[0] = layer_info_it->second[0];
-    UpdateLayerInfoVp8(frame, codec_header);
+    UpdateLayerInfoVp8(frame);
     return kHandOff;
   }
 
@@ -316,7 +319,7 @@
     frame->num_references = 1;
     frame->references[0] = layer_info_it->second[0];
 
-    UpdateLayerInfoVp8(frame, codec_header);
+    UpdateLayerInfoVp8(frame);
     return kHandOff;
   }
 
@@ -359,13 +362,14 @@
     frame->references[layer] = layer_info_it->second[layer];
   }
 
-  UpdateLayerInfoVp8(frame, codec_header);
+  UpdateLayerInfoVp8(frame);
   return kHandOff;
 }
 
-void RtpFrameReferenceFinder::UpdateLayerInfoVp8(
-    RtpFrameObject* frame,
-    const RTPVideoHeaderVP8& codec_header) {
+void RtpFrameReferenceFinder::UpdateLayerInfoVp8(RtpFrameObject* frame) {
+  rtc::Optional<RTPVideoTypeHeader> rtp_codec_header = frame->GetCodecHeader();
+  RTC_DCHECK(rtp_codec_header);
+  const RTPVideoHeaderVP8& codec_header = rtp_codec_header->VP8;
   uint8_t tl0_pic_idx = codec_header.tl0PicIdx;
   uint8_t temporal_index = codec_header.temporalIdx;
   auto layer_info_it = layer_info_.find(tl0_pic_idx);
@@ -392,8 +396,10 @@
 RtpFrameReferenceFinder::FrameDecision RtpFrameReferenceFinder::ManageFrameVp9(
     RtpFrameObject* frame) {
   rtc::Optional<RTPVideoTypeHeader> rtp_codec_header = frame->GetCodecHeader();
-  if (!rtp_codec_header)
+  if (!rtp_codec_header) {
+    LOG(LS_WARNING) << "Failed to get codec header from frame, dropping frame.";
     return kDrop;
+  }
 
   const RTPVideoHeaderVP9& codec_header = rtp_codec_header->VP9;
 
@@ -585,22 +591,8 @@
 
 void RtpFrameReferenceFinder::UnwrapPictureIds(RtpFrameObject* frame) {
   for (size_t i = 0; i < frame->num_references; ++i)
-    frame->references[i] = UnwrapPictureId(frame->references[i]);
-  frame->picture_id = UnwrapPictureId(frame->picture_id);
-}
-
-uint16_t RtpFrameReferenceFinder::UnwrapPictureId(uint16_t picture_id) {
-  RTC_DCHECK_NE(-1, last_unwrap_);
-
-  uint16_t unwrap_truncated = last_unwrap_ % kPicIdLength;
-  uint16_t diff = MinDiff<uint16_t, kPicIdLength>(unwrap_truncated, picture_id);
-
-  if (AheadOf<uint16_t, kPicIdLength>(picture_id, unwrap_truncated))
-    last_unwrap_ = Add<1 << 16>(last_unwrap_, diff);
-  else
-    last_unwrap_ = Subtract<1 << 16>(last_unwrap_, diff);
-
-  return last_unwrap_;
+    frame->references[i] = unwrapper_.Unwrap(frame->references[i]);
+  frame->picture_id = unwrapper_.Unwrap(frame->picture_id);
 }
 
 }  // namespace video_coding
diff --git a/modules/video_coding/rtp_frame_reference_finder.h b/modules/video_coding/rtp_frame_reference_finder.h
index f31ee64..601e7c4 100644
--- a/modules/video_coding/rtp_frame_reference_finder.h
+++ b/modules/video_coding/rtp_frame_reference_finder.h
@@ -99,8 +99,7 @@
 
   // Updates necessary layer info state used to determine frame references for
   // Vp8.
-  void UpdateLayerInfoVp8(RtpFrameObject* frame,
-                          const RTPVideoHeaderVP8& codec_header)
+  void UpdateLayerInfoVp8(RtpFrameObject* frame)
       EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Find references for Vp9 frames
@@ -126,8 +125,6 @@
 
   // Unwrap |frame|s picture id and its references to 16 bits.
   void UnwrapPictureIds(RtpFrameObject* frame) EXCLUSIVE_LOCKS_REQUIRED(crit_);
-  // All picture ids are unwrapped to 16 bits.
-  uint16_t UnwrapPictureId(uint16_t picture_id) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Returns true if the frame is old and should be dropped.
   // TODO(philipel): Remove when VP9 PID/TL0 does not jump mid-stream (should be
@@ -214,6 +211,14 @@
   int cleared_to_seq_num_ GUARDED_BY(crit_);
 
   OnCompleteFrameCallback* frame_callback_;
+
+  // Unwrapper used to unwrap generic RTP streams. In a generic stream we derive
+  // a picture id from the packet sequence number.
+  SeqNumUnwrapper<uint16_t> generic_unwrapper_ GUARDED_BY(crit_);
+
+  // Unwrapper used to unwrap VP8/VP9 streams which have their picture id
+  // specified.
+  SeqNumUnwrapper<uint16_t, kPicIdLength> unwrapper_ GUARDED_BY(crit_);
 };
 
 }  // namespace video_coding
diff --git a/modules/video_coding/rtp_frame_reference_finder_unittest.cc b/modules/video_coding/rtp_frame_reference_finder_unittest.cc
index 7d1c86d..5500430 100644
--- a/modules/video_coding/rtp_frame_reference_finder_unittest.cc
+++ b/modules/video_coding/rtp_frame_reference_finder_unittest.cc
@@ -54,16 +54,18 @@
 class TestRtpFrameReferenceFinder : public ::testing::Test,
                                     public OnCompleteFrameCallback {
  protected:
+  static constexpr uint64_t kUnwrappedSequenceStart = 10000000000000000000UL;
+
   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()); }
+  uint16_t Rand() { return rand_.Rand<uint16_t>(); }
 
   void OnCompleteFrame(std::unique_ptr<FrameObject> frame) override {
-    uint16_t pid = frame->picture_id;
+    int64_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()) {
@@ -203,7 +205,10 @@
   // 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 {
+  void CheckReferences(int64_t picture_id_offset,
+                       uint16_t sidx,
+                       T... refs) const {
+    int64_t pid = kUnwrappedSequenceStart + picture_id_offset;
     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 << ":"
@@ -211,54 +216,51 @@
       return;
     }
 
-    std::set<uint16_t> actual_refs;
-    for (uint8_t r = 0; r < frame_it->second->num_references; ++r) {
+    std::set<int64_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;
+    std::set<int64_t> expected_refs;
     RefsToSet(&expected_refs, refs...);
 
     ASSERT_EQ(expected_refs, actual_refs);
   }
 
   template <typename... T>
-  void CheckReferencesGeneric(uint16_t pid, T... refs) const {
+  void CheckReferencesGeneric(int64_t pid, T... refs) const {
     CheckReferences(pid, 0, refs...);
   }
 
   template <typename... T>
-  void CheckReferencesVp8(uint16_t pid, T... refs) const {
+  void CheckReferencesVp8(int64_t pid, T... refs) const {
     CheckReferences(pid, 0, refs...);
   }
 
   template <typename... T>
-  void CheckReferencesVp9(uint16_t pid, uint8_t sidx, T... refs) const {
+  void CheckReferencesVp9(int64_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);
+  void RefsToSet(std::set<int64_t>* m, int64_t ref, T... refs) const {
+    m->insert(ref + kUnwrappedSequenceStart);
     RefsToSet(m, refs...);
   }
 
-  void RefsToSet(std::set<uint16_t>* m) const {}
+  void RefsToSet(std::set<int64_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 {
+    bool operator()(const std::pair<int64_t, uint8_t> f1,
+                    const std::pair<int64_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>
+  std::map<std::pair<int64_t, uint8_t>, std::unique_ptr<FrameObject>, FrameComp>
       frames_from_callback_;
 };
 
@@ -281,8 +283,8 @@
   InsertGeneric(sn + 2, sn + 3, false);
 
   EXPECT_EQ(2UL, frames_from_callback_.size());
-  CheckReferencesGeneric(sn);
-  CheckReferencesGeneric(sn + 3, sn);
+  CheckReferencesGeneric(0);
+  CheckReferencesGeneric(3, 0);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, PaddingPacketsReorderedMultipleKeyframes) {
@@ -364,16 +366,16 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(6, 2);
+  CheckReferencesVp8(7, 6);
+  CheckReferencesVp8(9, 7);
+  CheckReferencesVp8(10);
+  CheckReferencesVp8(15, 10);
+  CheckReferencesVp8(16, 15);
+  CheckReferencesVp8(18, 16);
+  CheckReferencesVp8(19, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8NoPictureIdReordered) {
@@ -391,16 +393,16 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(6, 2);
+  CheckReferencesVp8(7, 6);
+  CheckReferencesVp8(9, 7);
+  CheckReferencesVp8(10);
+  CheckReferencesVp8(15, 10);
+  CheckReferencesVp8(16, 15);
+  CheckReferencesVp8(18, 16);
+  CheckReferencesVp8(19, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8KeyFrameReferences) {
@@ -408,7 +410,7 @@
   InsertVp8(sn, sn, true);
 
   ASSERT_EQ(1UL, frames_from_callback_.size());
-  CheckReferencesVp8(sn);
+  CheckReferencesVp8(0);
 }
 
 // Test with 1 temporal layer.
@@ -422,10 +424,10 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 1);
+  CheckReferencesVp8(3, 2);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8DuplicateTl1Frames) {
@@ -441,12 +443,12 @@
   InsertVp8(sn + 5, sn + 5, false, pid + 5, 1, 2);
 
   ASSERT_EQ(6UL, 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(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 1, 2);
+  CheckReferencesVp8(4, 2);
+  CheckReferencesVp8(5, 3, 4);
 }
 
 // Test with 1 temporal layer.
@@ -463,13 +465,13 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 1);
+  CheckReferencesVp8(3, 2);
+  CheckReferencesVp8(4, 3);
+  CheckReferencesVp8(5, 4);
+  CheckReferencesVp8(6, 5);
 }
 
 // Test with 2 temporal layers in a 01 pattern.
@@ -483,10 +485,10 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 1, 2);
 }
 
 // Test with 2 temporal layers in a 01 pattern.
@@ -504,14 +506,14 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 1, 2);
+  CheckReferencesVp8(4, 2);
+  CheckReferencesVp8(5, 3, 4);
+  CheckReferencesVp8(6, 4);
+  CheckReferencesVp8(7, 5, 6);
 }
 
 // Test with 3 temporal layers in a 0212 pattern.
@@ -533,18 +535,18 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 0, 1, 2);
+  CheckReferencesVp8(4, 0);
+  CheckReferencesVp8(5, 2, 3, 4);
+  CheckReferencesVp8(6, 2, 4);
+  CheckReferencesVp8(7, 4, 5, 6);
+  CheckReferencesVp8(8, 4);
+  CheckReferencesVp8(9, 8);
+  CheckReferencesVp8(10, 8);
+  CheckReferencesVp8(11, 8, 9, 10);
 }
 
 // Test with 3 temporal layers in a 0212 pattern.
@@ -557,8 +559,8 @@
   InsertVp8(sn + 3, sn + 3, false, pid + 3, 2, 55, false);
 
   ASSERT_EQ(2UL, frames_from_callback_.size());
-  CheckReferencesVp8(pid);
-  CheckReferencesVp8(pid + 2, pid);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(2, 0);
 }
 
 // Test with 3 temporal layers in a 0212 pattern.
@@ -580,18 +582,18 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 0, 1, 2);
+  CheckReferencesVp8(4, 0);
+  CheckReferencesVp8(5, 2, 3, 4);
+  CheckReferencesVp8(6, 2, 4);
+  CheckReferencesVp8(7, 4, 5, 6);
+  CheckReferencesVp8(8, 4);
+  CheckReferencesVp8(9, 8);
+  CheckReferencesVp8(10, 8);
+  CheckReferencesVp8(11, 8, 9, 10);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8InsertManyFrames_0212) {
@@ -600,6 +602,7 @@
 
   const int keyframes_to_insert = 50;
   const int frames_per_keyframe = 120;  // Should be a multiple of 4.
+  int64_t offset = 0;
   uint8_t tl0 = 128;
 
   for (int k = 0; k < keyframes_to_insert; ++k) {
@@ -607,29 +610,31 @@
     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);
+    CheckReferencesVp8(offset);
+    CheckReferencesVp8(offset + 1, offset);
+    CheckReferencesVp8(offset + 2, offset);
+    CheckReferencesVp8(offset + 3, offset, offset + 1, offset + 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;
+      int64_t offsetf = offset + 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);
+      CheckReferencesVp8(offsetf, offsetf - 4);
+      CheckReferencesVp8(offsetf + 1, offsetf, offsetf - 1, offsetf - 2);
+      CheckReferencesVp8(offsetf + 2, offsetf, offsetf - 2);
+      CheckReferencesVp8(offsetf + 3, offsetf, offsetf + 1, offsetf + 2);
       frames_from_callback_.clear();
       ++tl0;
     }
 
+    offset += frames_per_keyframe;
     pid += frames_per_keyframe;
     sn += frames_per_keyframe;
   }
@@ -650,13 +655,13 @@
   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);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(4, 2);
+  CheckReferencesVp8(5, 4);
+  CheckReferencesVp8(6, 4);
+  CheckReferencesVp8(7, 6, 5);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8Tl1SyncFrameAfterTl1Frame) {
@@ -666,9 +671,9 @@
   InsertVp8(1003, 1003, false, 5, 1, 248, true);   // due to this frame.
 
   ASSERT_EQ(3UL, frames_from_callback_.size());
-  CheckReferencesVp8(1);
-  CheckReferencesVp8(3, 1);
-  CheckReferencesVp8(5, 3);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(4, 2);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp8DetectMissingFrame_0212) {
@@ -685,15 +690,15 @@
   InsertVp8(5, 5, false, 5, 0, 2, false);
   ASSERT_EQ(8UL, frames_from_callback_.size());
 
-  CheckReferencesVp8(1);
-  CheckReferencesVp8(2, 1);
-  CheckReferencesVp8(3, 1);
-  CheckReferencesVp8(4, 3, 2, 1);
+  CheckReferencesVp8(0);
+  CheckReferencesVp8(1, 0);
+  CheckReferencesVp8(2, 0);
+  CheckReferencesVp8(3, 2, 1, 0);
 
-  CheckReferencesVp8(5, 1);
-  CheckReferencesVp8(6, 5, 4, 3);
-  CheckReferencesVp8(7, 5, 3);
-  CheckReferencesVp8(8, 7, 6, 5);
+  CheckReferencesVp8(4, 0);
+  CheckReferencesVp8(5, 4, 3, 2);
+  CheckReferencesVp8(6, 4, 2);
+  CheckReferencesVp8(7, 6, 5, 4);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofInsertOneFrame) {
@@ -704,7 +709,7 @@
 
   InsertVp9Gof(sn, sn, true, pid, 0, 0, 0, false, &ss);
 
-  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(0, 0);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9NoPictureIdReordered) {
@@ -722,16 +727,16 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(6, 0, 2);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(9, 0, 7);
+  CheckReferencesVp9(10, 0);
+  CheckReferencesVp9(15, 0, 10);
+  CheckReferencesVp9(16, 0, 15);
+  CheckReferencesVp9(18, 0, 16);
+  CheckReferencesVp9(19, 0, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_0) {
@@ -762,26 +767,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 1);
+  CheckReferencesVp9(3, 0, 2);
+  CheckReferencesVp9(4, 0, 3);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 5);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 7);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 9);
+  CheckReferencesVp9(11, 0, 10);
+  CheckReferencesVp9(12, 0, 11);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 13);
+  CheckReferencesVp9(15, 0, 14);
+  CheckReferencesVp9(16, 0, 15);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 17);
+  CheckReferencesVp9(19, 0, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_0) {
@@ -812,26 +817,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 1);
+  CheckReferencesVp9(3, 0, 2);
+  CheckReferencesVp9(4, 0, 3);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 5);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 7);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 9);
+  CheckReferencesVp9(11, 0, 10);
+  CheckReferencesVp9(12, 0, 11);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 13);
+  CheckReferencesVp9(15, 0, 14);
+  CheckReferencesVp9(16, 0, 15);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 17);
+  CheckReferencesVp9(19, 0, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofSkipFramesTemporalLayers_01) {
@@ -851,12 +856,12 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(4, 0);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 10);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofSkipFramesTemporalLayers_0212) {
@@ -871,10 +876,10 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 1, 2);
 
   // Skip frames with tl0 = 1
 
@@ -884,26 +889,26 @@
   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);
+  CheckReferencesVp9(8, 0);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 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);
+  CheckReferencesVp9(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);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 6);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_01) {
@@ -934,26 +939,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 2);
+  CheckReferencesVp9(4, 0, 2);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 6);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 10);
+  CheckReferencesVp9(12, 0, 10);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 12);
+  CheckReferencesVp9(15, 0, 14);
+  CheckReferencesVp9(16, 0, 14);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 16);
+  CheckReferencesVp9(19, 0, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_01) {
@@ -984,26 +989,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 2);
+  CheckReferencesVp9(4, 0, 2);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 6);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 10);
+  CheckReferencesVp9(12, 0, 10);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 12);
+  CheckReferencesVp9(15, 0, 14);
+  CheckReferencesVp9(16, 0, 14);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 16);
+  CheckReferencesVp9(19, 0, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayers_0212) {
@@ -1034,26 +1039,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 1, 2);
+  CheckReferencesVp9(4, 0, 0);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 5, 6);
+  CheckReferencesVp9(8, 0, 4);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 10);
+  CheckReferencesVp9(12, 0, 8);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 12);
+  CheckReferencesVp9(15, 0, 13, 14);
+  CheckReferencesVp9(16, 0, 12);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 16);
+  CheckReferencesVp9(19, 0, 17, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_0212) {
@@ -1084,26 +1089,26 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 1, 2);
+  CheckReferencesVp9(4, 0, 0);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 5, 6);
+  CheckReferencesVp9(8, 0, 4);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 10);
+  CheckReferencesVp9(12, 0, 8);
+  CheckReferencesVp9(13, 0, 12);
+  CheckReferencesVp9(14, 0, 12);
+  CheckReferencesVp9(15, 0, 13, 14);
+  CheckReferencesVp9(16, 0, 12);
+  CheckReferencesVp9(17, 0, 16);
+  CheckReferencesVp9(18, 0, 16);
+  CheckReferencesVp9(19, 0, 17, 18);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersUpSwitch_02120212) {
@@ -1130,22 +1135,22 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 1, 2);
+  CheckReferencesVp9(4, 0, 0);
+  CheckReferencesVp9(5, 0, 3, 4);
+  CheckReferencesVp9(6, 0, 2, 4);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 4);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 10);
+  CheckReferencesVp9(12, 0, 8);
+  CheckReferencesVp9(13, 0, 11, 12);
+  CheckReferencesVp9(14, 0, 10, 12);
+  CheckReferencesVp9(15, 0, 13, 14);
 }
 
 TEST_F(TestRtpFrameReferenceFinder,
@@ -1173,22 +1178,22 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 1, 2);
+  CheckReferencesVp9(4, 0, 0);
+  CheckReferencesVp9(5, 0, 3, 4);
+  CheckReferencesVp9(6, 0, 2, 4);
+  CheckReferencesVp9(7, 0, 6);
+  CheckReferencesVp9(8, 0, 4);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 10);
+  CheckReferencesVp9(12, 0, 8);
+  CheckReferencesVp9(13, 0, 11, 12);
+  CheckReferencesVp9(14, 0, 10, 12);
+  CheckReferencesVp9(15, 0, 13, 14);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9GofTemporalLayersReordered_01_0212) {
@@ -1212,18 +1217,18 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(1, 0, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(3, 0, 2);
+  CheckReferencesVp9(4, 0, 0);
+  CheckReferencesVp9(5, 0, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(7, 0, 5, 6);
+  CheckReferencesVp9(8, 0, 4);
+  CheckReferencesVp9(9, 0, 8);
+  CheckReferencesVp9(10, 0, 8);
+  CheckReferencesVp9(11, 0, 9, 10);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeOneFrame) {
@@ -1233,7 +1238,7 @@
   InsertVp9Flex(sn, sn, true, pid, 0, 0, 0, false);
 
   ASSERT_EQ(1UL, frames_from_callback_.size());
-  CheckReferencesVp9(pid, 0);
+  CheckReferencesVp9(0, 0);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeTwoSpatialLayers) {
@@ -1256,20 +1261,20 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(0, 1);
+  CheckReferencesVp9(1, 1, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(2, 1, 1);
+  CheckReferencesVp9(3, 1, 2);
+  CheckReferencesVp9(4, 0, 2);
+  CheckReferencesVp9(4, 1, 3);
+  CheckReferencesVp9(5, 1, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(6, 1, 5);
+  CheckReferencesVp9(7, 1, 6);
+  CheckReferencesVp9(8, 0, 6);
+  CheckReferencesVp9(8, 1, 7);
 }
 
 TEST_F(TestRtpFrameReferenceFinder, Vp9FlexibleModeTwoSpatialLayersReordered) {
@@ -1292,20 +1297,20 @@
   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);
+  CheckReferencesVp9(0, 0);
+  CheckReferencesVp9(0, 1);
+  CheckReferencesVp9(1, 1, 0);
+  CheckReferencesVp9(2, 0, 0);
+  CheckReferencesVp9(2, 1, 1);
+  CheckReferencesVp9(3, 1, 2);
+  CheckReferencesVp9(4, 0, 2);
+  CheckReferencesVp9(4, 1, 3);
+  CheckReferencesVp9(5, 1, 4);
+  CheckReferencesVp9(6, 0, 4);
+  CheckReferencesVp9(6, 1, 5);
+  CheckReferencesVp9(7, 1, 6);
+  CheckReferencesVp9(8, 0, 6);
+  CheckReferencesVp9(8, 1, 7);
 }
 
 }  // namespace video_coding
diff --git a/modules/video_coding/sequence_number_util.h b/modules/video_coding/sequence_number_util.h
index 008e5f1..05f3367 100644
--- a/modules/video_coding/sequence_number_util.h
+++ b/modules/video_coding/sequence_number_util.h
@@ -91,7 +91,13 @@
       "Type unwrapped must be an unsigned integer smaller than uint64_t.");
 
  public:
-  SeqNumUnwrapper() : last_unwrapped_(0) {}
+  // We want a value that is close to 2^63 for two reasons. Firstly, we
+  // can unwrap wrapping numbers in either direction, and secondly, we avoid
+  // causing a crash on bad input. We also want the default value to be somewhat
+  // human readable, a power of 10 for example.
+  static constexpr uint64_t kDefaultStartValue = 10000000000000000000UL;
+
+  SeqNumUnwrapper() : last_unwrapped_(kDefaultStartValue) {}
   explicit SeqNumUnwrapper(uint64_t start_at) : last_unwrapped_(start_at) {}
 
   uint64_t Unwrap(T value) {
diff --git a/modules/video_coding/sequence_number_util_unittest.cc b/modules/video_coding/sequence_number_util_unittest.cc
index e0db1a8..8555fc2 100644
--- a/modules/video_coding/sequence_number_util_unittest.cc
+++ b/modules/video_coding/sequence_number_util_unittest.cc
@@ -212,7 +212,7 @@
 #if GTEST_HAS_DEATH_TEST
 #if !defined(WEBRTC_ANDROID)
 TEST(SeqNumUnwrapper, NoBackWardWrap) {
-  SeqNumUnwrapper<uint8_t> unwrapper;
+  SeqNumUnwrapper<uint8_t> unwrapper(0);
   EXPECT_EQ(0U, unwrapper.Unwrap(0));
 
   // The unwrapped sequence is not allowed to wrap, if that happens the
@@ -232,13 +232,13 @@
 #endif
 
 TEST(SeqNumUnwrapper, ForwardWrap) {
-  SeqNumUnwrapper<uint8_t> unwrapper;
+  SeqNumUnwrapper<uint8_t> unwrapper(0);
   EXPECT_EQ(0U, unwrapper.Unwrap(255));
   EXPECT_EQ(1U, unwrapper.Unwrap(0));
 }
 
 TEST(SeqNumUnwrapper, ForwardWrapWithDivisor) {
-  SeqNumUnwrapper<uint8_t, 33> unwrapper;
+  SeqNumUnwrapper<uint8_t, 33> unwrapper(0);
   EXPECT_EQ(0U, unwrapper.Unwrap(30));
   EXPECT_EQ(6U, unwrapper.Unwrap(3));
 }
@@ -256,7 +256,7 @@
 }
 
 TEST(SeqNumUnwrapper, Unwrap) {
-  SeqNumUnwrapper<uint16_t> unwrapper;
+  SeqNumUnwrapper<uint16_t> unwrapper(0);
   const uint16_t kMax = std::numeric_limits<uint16_t>::max();
   const uint16_t kMaxDist = kMax / 2 + 1;
 
@@ -294,7 +294,7 @@
   SeqNumUnwrapper<uint16_t, kLargeNumber> unwrapper;
 
   uint16_t next_unwrap = 0;
-  uint64_t expected = 0;
+  uint64_t expected = decltype(unwrapper)::kDefaultStartValue;
   for (int i = 0; i < kNumWraps * 2 + 1; ++i) {
     EXPECT_EQ(expected, unwrapper.Unwrap(next_unwrap));
     expected += kMaxStep;
diff --git a/video/rtp_video_stream_receiver.cc b/video/rtp_video_stream_receiver.cc
index 0dbb2f7..a47055a 100644
--- a/video/rtp_video_stream_receiver.cc
+++ b/video/rtp_video_stream_receiver.cc
@@ -589,7 +589,7 @@
   return true;
 }
 
-void RtpVideoStreamReceiver::FrameContinuous(uint16_t picture_id) {
+void RtpVideoStreamReceiver::FrameContinuous(int64_t picture_id) {
   if (!nack_module_)
     return;
 
@@ -604,7 +604,7 @@
     nack_module_->ClearUpTo(seq_num);
 }
 
-void RtpVideoStreamReceiver::FrameDecoded(uint16_t picture_id) {
+void RtpVideoStreamReceiver::FrameDecoded(int64_t picture_id) {
   int seq_num = -1;
   {
     rtc::CritScope lock(&last_seq_num_cs_);
diff --git a/video/rtp_video_stream_receiver.h b/video/rtp_video_stream_receiver.h
index 15af2e6..f65280e 100644
--- a/video/rtp_video_stream_receiver.h
+++ b/video/rtp_video_stream_receiver.h
@@ -93,9 +93,9 @@
 
   bool DeliverRtcp(const uint8_t* rtcp_packet, size_t rtcp_packet_length);
 
-  void FrameContinuous(uint16_t seq_num);
+  void FrameContinuous(int64_t seq_num);
 
-  void FrameDecoded(uint16_t seq_num);
+  void FrameDecoded(int64_t seq_num);
 
   void SignalNetworkState(NetworkState state);
 
@@ -199,8 +199,8 @@
   rtc::scoped_refptr<video_coding::PacketBuffer> packet_buffer_;
   std::unique_ptr<video_coding::RtpFrameReferenceFinder> reference_finder_;
   rtc::CriticalSection last_seq_num_cs_;
-  std::map<uint16_t, uint16_t, DescendingSeqNumComp<uint16_t>>
-      last_seq_num_for_pic_id_ GUARDED_BY(last_seq_num_cs_);
+  std::map<int64_t, uint16_t> last_seq_num_for_pic_id_
+      GUARDED_BY(last_seq_num_cs_);
   video_coding::H264SpsPpsTracker tracker_;
   // TODO(johan): Remove pt_codec_params_ once
   // https://bugs.chromium.org/p/webrtc/issues/detail?id=6883 is resolved.