1 files changed, 70 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/rtp_seq_num_only_ref_finder.h b/third_party/libwebrtc/modules/video_coding/rtp_seq_num_only_ref_finder.h
new file mode 100644
index 0000000000..166b6a7f0c
--- /dev/null
+++ b/third_party/libwebrtc/modules/video_coding/rtp_seq_num_only_ref_finder.h
@@ -0,0 +1,70 @@
+/*
+ *  Copyright (c) 2020 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.
+ */
+
+#ifndef MODULES_VIDEO_CODING_RTP_SEQ_NUM_ONLY_REF_FINDER_H_
+#define MODULES_VIDEO_CODING_RTP_SEQ_NUM_ONLY_REF_FINDER_H_
+
+#include <deque>
+#include <map>
+#include <memory>
+#include <set>
+#include <utility>
+
+#include "absl/container/inlined_vector.h"
+#include "modules/rtp_rtcp/source/frame_object.h"
+#include "modules/video_coding/rtp_frame_reference_finder.h"
+#include "rtc_base/numerics/sequence_number_unwrapper.h"
+
+namespace webrtc {
+
+class RtpSeqNumOnlyRefFinder {
+ public:
+  RtpSeqNumOnlyRefFinder() = default;
+
+  RtpFrameReferenceFinder::ReturnVector ManageFrame(
+      std::unique_ptr<RtpFrameObject> frame);
+  RtpFrameReferenceFinder::ReturnVector PaddingReceived(uint16_t seq_num);
+  void ClearTo(uint16_t seq_num);
+
+ private:
+  static constexpr int kMaxStashedFrames = 100;
+  static constexpr int kMaxPaddingAge = 100;
+
+  enum FrameDecision { kStash, kHandOff, kDrop };
+
+  FrameDecision ManageFrameInternal(RtpFrameObject* frame);
+  void RetryStashedFrames(RtpFrameReferenceFinder::ReturnVector& res);
+  void UpdateLastPictureIdWithPadding(uint16_t seq_num);
+
+  // For every group of pictures, hold two sequence numbers. The first being
+  // the sequence number of the last packet of the last completed frame, and
+  // the second being the sequence number of the last packet of the last
+  // completed frame advanced by any potential continuous packets of padding.
+  std::map<uint16_t,
+           std::pair<uint16_t, uint16_t>,
+           DescendingSeqNumComp<uint16_t>>
+      last_seq_num_gop_;
+
+  // Padding packets that have been received but that are not yet continuous
+  // with any group of pictures.
+  std::set<uint16_t, DescendingSeqNumComp<uint16_t>> stashed_padding_;
+
+  // Frames that have been fully received but didn't have all the information
+  // needed to determine their references.
+  std::deque<std::unique_ptr<RtpFrameObject>> stashed_frames_;
+
+  // Unwrapper used to unwrap generic RTP streams. In a generic stream we derive
+  // a picture id from the packet sequence number.
+  SeqNumUnwrapper<uint16_t> rtp_seq_num_unwrapper_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_RTP_SEQ_NUM_ONLY_REF_FINDER_H_