1 files changed, 105 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/video_coding/rtp_vp9_ref_finder.h b/third_party/libwebrtc/modules/video_coding/rtp_vp9_ref_finder.h
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+++ b/third_party/libwebrtc/modules/video_coding/rtp_vp9_ref_finder.h
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+/*
+ *  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_VP9_REF_FINDER_H_
+#define MODULES_VIDEO_CODING_RTP_VP9_REF_FINDER_H_
+
+#include <deque>
+#include <map>
+#include <memory>
+#include <set>
+
+#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 RtpVp9RefFinder {
+ public:
+  RtpVp9RefFinder() = default;
+
+  RtpFrameReferenceFinder::ReturnVector ManageFrame(
+      std::unique_ptr<RtpFrameObject> frame);
+  void ClearTo(uint16_t seq_num);
+
+ private:
+  static constexpr int kFrameIdLength = 1 << 15;
+  static constexpr int kMaxGofSaved = 50;
+  static constexpr int kMaxLayerInfo = 50;
+  static constexpr int kMaxNotYetReceivedFrames = 100;
+  static constexpr int kMaxStashedFrames = 100;
+  static constexpr int kMaxTemporalLayers = 5;
+
+  enum FrameDecision { kStash, kHandOff, kDrop };
+
+  struct GofInfo {
+    GofInfo(GofInfoVP9* gof, uint16_t last_picture_id)
+        : gof(gof), last_picture_id(last_picture_id) {}
+    GofInfoVP9* gof;
+    uint16_t last_picture_id;
+  };
+
+  struct UnwrappedTl0Frame {
+    int64_t unwrapped_tl0;
+    std::unique_ptr<RtpFrameObject> frame;
+  };
+
+  FrameDecision ManageFrameFlexible(RtpFrameObject* frame,
+                                    const RTPVideoHeaderVP9& vp9_header);
+  FrameDecision ManageFrameGof(RtpFrameObject* frame,
+                               const RTPVideoHeaderVP9& vp9_header,
+                               int64_t unwrapped_tl0);
+  void RetryStashedFrames(RtpFrameReferenceFinder::ReturnVector& res);
+
+  bool MissingRequiredFrameVp9(uint16_t picture_id, const GofInfo& info);
+
+  void FrameReceivedVp9(uint16_t picture_id, GofInfo* info);
+  bool UpSwitchInIntervalVp9(uint16_t picture_id,
+                             uint8_t temporal_idx,
+                             uint16_t pid_ref);
+
+  void FlattenFrameIdAndRefs(RtpFrameObject* frame, bool inter_layer_predicted);
+
+  // Frames that have been fully received but didn't have all the information
+  // needed to determine their references.
+  std::deque<UnwrappedTl0Frame> stashed_frames_;
+
+  // Where the current scalability structure is in the
+  // `scalability_structures_` array.
+  uint8_t current_ss_idx_ = 0;
+
+  // Holds received scalability structures.
+  std::array<GofInfoVP9, kMaxGofSaved> scalability_structures_;
+
+  // Holds the the Gof information for a given unwrapped TL0 picture index.
+  std::map<int64_t, GofInfo> gof_info_;
+
+  // Keep track of which picture id and which temporal layer that had the
+  // up switch flag set.
+  std::map<uint16_t, uint8_t, DescendingSeqNumComp<uint16_t, kFrameIdLength>>
+      up_switch_;
+
+  // For every temporal layer, keep a set of which frames that are missing.
+  std::array<std::set<uint16_t, DescendingSeqNumComp<uint16_t, kFrameIdLength>>,
+             kMaxTemporalLayers>
+      missing_frames_for_layer_;
+
+  // Unwrapper used to unwrap VP8/VP9 streams which have their picture id
+  // specified.
+  SeqNumUnwrapper<uint16_t, kFrameIdLength> unwrapper_;
+
+  SeqNumUnwrapper<uint8_t> tl0_unwrapper_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_VIDEO_CODING_RTP_VP9_REF_FINDER_H_