diff --git a/webrtc/modules/video_coding/sequence_number_util.h b/webrtc/modules/video_coding/sequence_number_util.h
index 8a139a34dc..e3bc38e68e 100644
--- a/webrtc/modules/video_coding/sequence_number_util.h
+++ b/webrtc/modules/video_coding/sequence_number_util.h
@@ -15,6 +15,8 @@
 #include <type_traits>
 
 #include "webrtc/rtc_base/mod_ops.h"
+#include "webrtc/rtc_base/optional.h"
+#include "webrtc/rtc_base/safe_compare.h"
 
 namespace webrtc {
 
@@ -24,7 +26,7 @@ namespace webrtc {
 // from each other, then the sequence number with the highest value is
 // considered to be ahead.
 template <typename T, T M>
-inline bool AheadOrAt(T a, T b) {
+inline typename std::enable_if<(M > 0), bool>::type AheadOrAt(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   const T maxDist = M / 2;
@@ -33,8 +35,8 @@ inline bool AheadOrAt(T a, T b) {
   return ForwardDiff<T, M>(b, a) <= maxDist;
 }
 
-template <typename T>
-inline bool AheadOrAt(T a, T b) {
+template <typename T, T M>
+inline typename std::enable_if<(M == 0), bool>::type AheadOrAt(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   const T maxDist = std::numeric_limits<T>::max() / 2 + T(1);
@@ -43,66 +45,76 @@ inline bool AheadOrAt(T a, T b) {
   return ForwardDiff(b, a) < maxDist;
 }
 
+template <typename T>
+inline bool AheadOrAt(T a, T b) {
+  return AheadOrAt<T, 0>(a, b);
+}
+
 // Test if the sequence number |a| is ahead of sequence number |b|.
 //
 // If |M| is an even number and the two sequence numbers are at max distance
 // from each other, then the sequence number with the highest value is
 // considered to be ahead.
-template <typename T, T M>
+template <typename T, T M = 0>
 inline bool AheadOf(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   return a != b && AheadOrAt<T, M>(a, b);
 }
 
-template <typename T>
-inline bool AheadOf(T a, T b) {
-  static_assert(std::is_unsigned<T>::value,
-                "Type must be an unsigned integer.");
-  return a != b && AheadOrAt(a, b);
-}
-
-namespace internal {
-
-template <typename T, typename M>
-struct SeqNumComp;
-
-template <typename T, T M>
-struct SeqNumComp<T, std::integral_constant<T, M>> {
+// Comparator used to compare sequence numbers in a continuous fashion.
+//
+// WARNING! If used to sort sequence numbers of length M then the interval
+//          covered by the sequence numbers may not be larger than floor(M/2).
+template <typename T, T M = 0>
+struct AscendingSeqNumComp {
   bool operator()(T a, T b) const { return AheadOf<T, M>(a, b); }
 };
 
-template <typename T>
-struct SeqNumComp<T, std::integral_constant<T, T(0)>> {
-  bool operator()(T a, T b) const { return AheadOf<T>(a, b); }
-};
-
-}  // namespace internal
-
 // Comparator used to compare sequence numbers in a continuous fashion.
 //
 // WARNING! If used to sort sequence numbers of length M then the interval
 //          covered by the sequence numbers may not be larger than floor(M/2).
 template <typename T, T M = 0>
-struct AscendingSeqNumComp
-    : private internal::SeqNumComp<T, std::integral_constant<T, M>> {
-  bool operator()(T a, T b) const {
-    return internal::SeqNumComp<T, std::integral_constant<T, M>>::operator()(a,
-                                                                             b);
-  }
+struct DescendingSeqNumComp {
+  bool operator()(T a, T b) const { return AheadOf<T, M>(b, a); }
 };
 
-// Comparator used to compare sequence numbers in a continuous fashion.
-//
-// WARNING! If used to sort sequence numbers of length M then the interval
-//          covered by the sequence numbers may not be larger than floor(M/2).
+// A sequencer number unwrapper where the start value of the unwrapped sequence
+// can be set. The unwrapped value is not allowed to wrap.
 template <typename T, T M = 0>
-struct DescendingSeqNumComp
-    : private internal::SeqNumComp<T, std::integral_constant<T, M>> {
-  bool operator()(T a, T b) const {
-    return internal::SeqNumComp<T, std::integral_constant<T, M>>::operator()(b,
-                                                                             a);
+class SeqNumUnwrapper {
+  static_assert(
+      std::is_unsigned<T>::value &&
+          rtc::SafeLt(std::numeric_limits<T>::max(),
+                      std::numeric_limits<uint64_t>::max()),
+      "Type unwrapped must be an unsigned integer smaller than uint64_t.");
+
+ public:
+  SeqNumUnwrapper() : last_unwrapped_(0) {}
+  explicit SeqNumUnwrapper(uint64_t start_at) : last_unwrapped_(start_at) {}
+
+  uint64_t Unwrap(T value) {
+    if (!last_value_)
+      last_value_.emplace(value);
+
+    uint64_t unwrapped = 0;
+    if (AheadOrAt<T, M>(value, *last_value_)) {
+      unwrapped = last_unwrapped_ + ForwardDiff<T, M>(*last_value_, value);
+      RTC_CHECK_GE(unwrapped, last_unwrapped_);
+    } else {
+      unwrapped = last_unwrapped_ - ReverseDiff<T, M>(*last_value_, value);
+      RTC_CHECK_LT(unwrapped, last_unwrapped_);
+    }
+
+    *last_value_ = value;
+    last_unwrapped_ = unwrapped;
+    return last_unwrapped_;
   }
+
+ private:
+  uint64_t last_unwrapped_;
+  rtc::Optional<T> last_value_;
 };
 
 }  // namespace webrtc
diff --git a/webrtc/modules/video_coding/sequence_number_util_unittest.cc b/webrtc/modules/video_coding/sequence_number_util_unittest.cc
index 1ed78b95b8..12cc911e41 100644
--- a/webrtc/modules/video_coding/sequence_number_util_unittest.cc
+++ b/webrtc/modules/video_coding/sequence_number_util_unittest.cc
@@ -209,4 +209,108 @@ TEST_F(TestSeqNumUtil, SeqNumComparatorWithDivisor) {
   }
 }
 
+TEST(SeqNumUnwrapper, NoBackWardWrap) {
+  SeqNumUnwrapper<uint8_t> unwrapper;
+  EXPECT_EQ(0U, unwrapper.Unwrap(0));
+
+  // The unwrapped sequence is not allowed to wrap, if that happens the
+  // SeqNumUnwrapper should have been constructed with a higher start value.
+  ASSERT_DEATH_IF_SUPPORTED(unwrapper.Unwrap(255), "");
+}
+
+TEST(SeqNumUnwrapper, NoForwardWrap) {
+  SeqNumUnwrapper<uint32_t> unwrapper(std::numeric_limits<uint64_t>::max());
+  EXPECT_EQ(std::numeric_limits<uint64_t>::max(), unwrapper.Unwrap(0));
+
+  // The unwrapped sequence is not allowed to wrap, if that happens the
+  // SeqNumUnwrapper should have been constructed with a lower start value.
+  ASSERT_DEATH_IF_SUPPORTED(unwrapper.Unwrap(1), "");
+}
+
+TEST(SeqNumUnwrapper, ForwardWrap) {
+  SeqNumUnwrapper<uint8_t> unwrapper;
+  EXPECT_EQ(0U, unwrapper.Unwrap(255));
+  EXPECT_EQ(1U, unwrapper.Unwrap(0));
+}
+
+TEST(SeqNumUnwrapper, ForwardWrapWithDivisor) {
+  SeqNumUnwrapper<uint8_t, 33> unwrapper;
+  EXPECT_EQ(0U, unwrapper.Unwrap(30));
+  EXPECT_EQ(6U, unwrapper.Unwrap(3));
+}
+
+TEST(SeqNumUnwrapper, BackWardWrap) {
+  SeqNumUnwrapper<uint8_t> unwrapper(10);
+  EXPECT_EQ(10U, unwrapper.Unwrap(0));
+  EXPECT_EQ(8U, unwrapper.Unwrap(254));
+}
+
+TEST(SeqNumUnwrapper, BackWardWrapWithDivisor) {
+  SeqNumUnwrapper<uint8_t, 33> unwrapper(10);
+  EXPECT_EQ(10U, unwrapper.Unwrap(0));
+  EXPECT_EQ(8U, unwrapper.Unwrap(31));
+}
+
+TEST(SeqNumUnwrapper, Unwrap) {
+  SeqNumUnwrapper<uint16_t> unwrapper;
+  const uint16_t kMax = std::numeric_limits<uint16_t>::max();
+  const uint16_t kMaxDist = kMax / 2 + 1;
+
+  EXPECT_EQ(0U, unwrapper.Unwrap(0));
+  EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
+  EXPECT_EQ(0U, unwrapper.Unwrap(0));
+
+  EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
+  EXPECT_EQ(kMax, unwrapper.Unwrap(kMax));
+  EXPECT_EQ(kMax + 1U, unwrapper.Unwrap(0));
+  EXPECT_EQ(kMax, unwrapper.Unwrap(kMax));
+  EXPECT_EQ(kMaxDist, unwrapper.Unwrap(kMaxDist));
+  EXPECT_EQ(0U, unwrapper.Unwrap(0));
+}
+
+TEST(SeqNumUnwrapper, UnwrapOddDivisor) {
+  SeqNumUnwrapper<uint8_t, 11> unwrapper(10);
+
+  EXPECT_EQ(10U, unwrapper.Unwrap(10));
+  EXPECT_EQ(11U, unwrapper.Unwrap(0));
+  EXPECT_EQ(16U, unwrapper.Unwrap(5));
+  EXPECT_EQ(21U, unwrapper.Unwrap(10));
+  EXPECT_EQ(22U, unwrapper.Unwrap(0));
+  EXPECT_EQ(17U, unwrapper.Unwrap(6));
+  EXPECT_EQ(12U, unwrapper.Unwrap(1));
+  EXPECT_EQ(7U, unwrapper.Unwrap(7));
+  EXPECT_EQ(2U, unwrapper.Unwrap(2));
+  EXPECT_EQ(0U, unwrapper.Unwrap(0));
+}
+
+TEST(SeqNumUnwrapper, ManyForwardWraps) {
+  const int kLargeNumber = 4711;
+  const int kMaxStep = kLargeNumber / 2;
+  const int kNumWraps = 100;
+  SeqNumUnwrapper<uint16_t, kLargeNumber> unwrapper;
+
+  uint16_t next_unwrap = 0;
+  uint64_t expected = 0;
+  for (int i = 0; i < kNumWraps * 2 + 1; ++i) {
+    EXPECT_EQ(expected, unwrapper.Unwrap(next_unwrap));
+    expected += kMaxStep;
+    next_unwrap = (next_unwrap + kMaxStep) % kLargeNumber;
+  }
+}
+
+TEST(SeqNumUnwrapper, ManyBackwardWraps) {
+  const int kLargeNumber = 4711;
+  const int kMaxStep = kLargeNumber / 2;
+  const int kNumWraps = 100;
+  SeqNumUnwrapper<uint16_t, kLargeNumber> unwrapper(kLargeNumber * kNumWraps);
+
+  uint16_t next_unwrap = 0;
+  uint64_t expected = kLargeNumber * kNumWraps;
+  for (uint16_t i = 0; i < kNumWraps * 2 + 1; ++i) {
+    EXPECT_EQ(expected, unwrapper.Unwrap(next_unwrap));
+    expected -= kMaxStep;
+    next_unwrap = (next_unwrap + kMaxStep + 1) % kLargeNumber;
+  }
+}
+
 }  // namespace webrtc
diff --git a/webrtc/rtc_base/mod_ops.h b/webrtc/rtc_base/mod_ops.h
index 211f2e3553..f8cb951e83 100644
--- a/webrtc/rtc_base/mod_ops.h
+++ b/webrtc/rtc_base/mod_ops.h
@@ -59,8 +59,10 @@ inline unsigned long Subtract(unsigned long a, unsigned long b) {  // NOLINT
 // #################################################
 // -->----->                              |----->---
 //
+// If M > 0 then wrapping occurs at M, if M == 0 then wrapping occurs at the
+// largest value representable by T.
 template <typename T, T M>
-inline T ForwardDiff(T a, T b) {
+inline typename std::enable_if<(M > 0), T>::type ForwardDiff(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   RTC_DCHECK_LT(a, M);
@@ -68,13 +70,18 @@ inline T ForwardDiff(T a, T b) {
   return a <= b ? b - a : M - (a - b);
 }
 
-template <typename T>
-inline T ForwardDiff(T a, T b) {
+template <typename T, T M>
+inline typename std::enable_if<(M == 0), T>::type ForwardDiff(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   return b - a;
 }
 
+template <typename T>
+inline T ForwardDiff(T a, T b) {
+  return ForwardDiff<T, 0>(a, b);
+}
+
 // Calculates the reverse difference between two wrapping numbers.
 //
 // Example:
@@ -97,8 +104,10 @@ inline T ForwardDiff(T a, T b) {
 // #################################################
 // ---<-----|                             |<-----<--
 //
+// If M > 0 then wrapping occurs at M, if M == 0 then wrapping occurs at the
+// largest value representable by T.
 template <typename T, T M>
-inline T ReverseDiff(T a, T b) {
+inline typename std::enable_if<(M > 0), T>::type ReverseDiff(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   RTC_DCHECK_LT(a, M);
@@ -106,30 +115,28 @@ inline T ReverseDiff(T a, T b) {
   return b <= a ? a - b : M - (b - a);
 }
 
-template <typename T>
-inline T ReverseDiff(T a, T b) {
+template <typename T, T M>
+inline typename std::enable_if<(M == 0), T>::type ReverseDiff(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   return a - b;
 }
 
+template <typename T>
+inline T ReverseDiff(T a, T b) {
+  return ReverseDiff<T, 0>(a, b);
+}
+
 // Calculates the minimum distance between to wrapping numbers.
 //
 // The minimum distance is defined as min(ForwardDiff(a, b), ReverseDiff(a, b))
-template <typename T, T M>
+template <typename T, T M = 0>
 inline T MinDiff(T a, T b) {
   static_assert(std::is_unsigned<T>::value,
                 "Type must be an unsigned integer.");
   return std::min(ForwardDiff<T, M>(a, b), ReverseDiff<T, M>(a, b));
 }
 
-template <typename T>
-inline T MinDiff(T a, T b) {
-  static_assert(std::is_unsigned<T>::value,
-                "Type must be an unsigned integer.");
-  return std::min(ForwardDiff(a, b), ReverseDiff(a, b));
-}
-
 }  // namespace webrtc
 
 #endif  // WEBRTC_RTC_BASE_MOD_OPS_H_
diff --git a/webrtc/rtc_base/mod_ops_unittest.cc b/webrtc/rtc_base/mod_ops_unittest.cc
index c375305e2d..d39ea061b6 100644
--- a/webrtc/rtc_base/mod_ops_unittest.cc
+++ b/webrtc/rtc_base/mod_ops_unittest.cc
@@ -87,6 +87,14 @@ TEST_F(TestModOps, ForwardDiff) {
   }
 }
 
+TEST_F(TestModOps, ForwardDiffWithDivisor) {
+  ASSERT_EQ(122, (ForwardDiff<uint8_t, 123>(0, 122)));
+  ASSERT_EQ(0, (ForwardDiff<uint8_t, 123>(122, 122)));
+  ASSERT_EQ(122, (ForwardDiff<uint8_t, 123>(1, 0)));
+  ASSERT_EQ(0, (ForwardDiff<uint8_t, 123>(0, 0)));
+  ASSERT_EQ(1, (ForwardDiff<uint8_t, 123>(122, 0)));
+}
+
 TEST_F(TestModOps, ReverseDiff) {
   ASSERT_EQ(0u, ReverseDiff(4711u, 4711u));
 
@@ -106,6 +114,14 @@ TEST_F(TestModOps, ReverseDiff) {
   }
 }
 
+TEST_F(TestModOps, ReverseDiffWithDivisor) {
+  ASSERT_EQ(1, (ReverseDiff<uint8_t, 123>(0, 122)));
+  ASSERT_EQ(0, (ReverseDiff<uint8_t, 123>(122, 122)));
+  ASSERT_EQ(1, (ReverseDiff<uint8_t, 123>(1, 0)));
+  ASSERT_EQ(0, (ReverseDiff<uint8_t, 123>(0, 0)));
+  ASSERT_EQ(122, (ReverseDiff<uint8_t, 123>(122, 0)));
+}
+
 TEST_F(TestModOps, MinDiff) {
   for (uint16_t i = 0; i < 256; ++i) {
     ASSERT_EQ(0, MinDiff<uint8_t>(i, i));