1 files changed, 41 insertions, 0 deletions
diff --git a/third_party/libwebrtc/video/unique_timestamp_counter.cc b/third_party/libwebrtc/video/unique_timestamp_counter.cc
new file mode 100644
index 0000000000..14cc039ec9
--- /dev/null
+++ b/third_party/libwebrtc/video/unique_timestamp_counter.cc
@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2019 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 "video/unique_timestamp_counter.h"
+
+#include <cstdint>
+#include <memory>
+#include <set>
+
+namespace webrtc {
+namespace {
+
+constexpr int kMaxHistory = 1000;
+
+}  // namespace
+
+UniqueTimestampCounter::UniqueTimestampCounter()
+    : latest_(std::make_unique<uint32_t[]>(kMaxHistory)) {}
+
+void UniqueTimestampCounter::Add(uint32_t value) {
+  if (value == last_ || !search_index_.insert(value).second) {
+    // Already known.
+    return;
+  }
+  int index = unique_seen_ % kMaxHistory;
+  if (unique_seen_ >= kMaxHistory) {
+    search_index_.erase(latest_[index]);
+  }
+  latest_[index] = value;
+  last_ = value;
+  ++unique_seen_;
+}
+
+}  // namespace webrtc