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rtp_vp9_ref_finder.h (3726B)

      1 /*
      2 *  Copyright (c) 2020 The WebRTC project authors. All Rights Reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #ifndef MODULES_VIDEO_CODING_RTP_VP9_REF_FINDER_H_
     12 #define MODULES_VIDEO_CODING_RTP_VP9_REF_FINDER_H_
     13 
     14 #include <array>
     15 #include <cstdint>
     16 #include <deque>
     17 #include <map>
     18 #include <memory>
     19 #include <set>
     20 
     21 #include "modules/rtp_rtcp/source/frame_object.h"
     22 #include "modules/video_coding/codecs/vp9/include/vp9_globals.h"
     23 #include "modules/video_coding/rtp_frame_reference_finder.h"
     24 #include "rtc_base/numerics/sequence_number_unwrapper.h"
     25 #include "rtc_base/numerics/sequence_number_util.h"
     26 
     27 namespace webrtc {
     28 
     29 class RtpVp9RefFinder {
     30 public:
     31  RtpVp9RefFinder() = default;
     32 
     33  RtpFrameReferenceFinder::ReturnVector ManageFrame(
     34      std::unique_ptr<RtpFrameObject> frame);
     35  void ClearTo(uint16_t seq_num);
     36 
     37 private:
     38  static constexpr int kFrameIdLength = 1 << 15;
     39  static constexpr int kMaxGofSaved = 50;
     40  static constexpr int kMaxLayerInfo = 50;
     41  static constexpr int kMaxNotYetReceivedFrames = 100;
     42  static constexpr int kMaxStashedFrames = 100;
     43  static constexpr int kMaxTemporalLayers = 5;
     44 
     45  enum FrameDecision { kStash, kHandOff, kDrop };
     46 
     47  struct GofInfo {
     48    GofInfo(GofInfoVP9* gof, uint16_t last_picture_id)
     49        : gof(gof), last_picture_id(last_picture_id) {}
     50    GofInfoVP9* gof;
     51    uint16_t last_picture_id;
     52  };
     53 
     54  struct UnwrappedTl0Frame {
     55    int64_t unwrapped_tl0;
     56    std::unique_ptr<RtpFrameObject> frame;
     57  };
     58 
     59  FrameDecision ManageFrameFlexible(RtpFrameObject* frame,
     60                                    const RTPVideoHeaderVP9& vp9_header);
     61  FrameDecision ManageFrameGof(RtpFrameObject* frame,
     62                               const RTPVideoHeaderVP9& vp9_header,
     63                               int64_t unwrapped_tl0);
     64  void RetryStashedFrames(RtpFrameReferenceFinder::ReturnVector& res);
     65 
     66  bool MissingRequiredFrameVp9(uint16_t picture_id, const GofInfo& info);
     67 
     68  void FrameReceivedVp9(uint16_t picture_id, GofInfo* info);
     69  bool UpSwitchInIntervalVp9(uint16_t picture_id,
     70                             uint8_t temporal_idx,
     71                             uint16_t pid_ref);
     72 
     73  void FlattenFrameIdAndRefs(RtpFrameObject* frame, bool inter_layer_predicted);
     74 
     75  // Frames that have been fully received but didn't have all the information
     76  // needed to determine their references.
     77  std::deque<UnwrappedTl0Frame> stashed_frames_;
     78 
     79  // Where the current scalability structure is in the
     80  // `scalability_structures_` array.
     81  uint8_t current_ss_idx_ = 0;
     82 
     83  // Holds received scalability structures.
     84  std::array<GofInfoVP9, kMaxGofSaved> scalability_structures_;
     85 
     86  // Holds the the Gof information for a given unwrapped TL0 picture index.
     87  std::map<int64_t, GofInfo> gof_info_;
     88 
     89  // Keep track of which picture id and which temporal layer that had the
     90  // up switch flag set.
     91  std::map<uint16_t, uint8_t, DescendingSeqNumComp<uint16_t, kFrameIdLength>>
     92      up_switch_;
     93 
     94  // For every temporal layer, keep a set of which frames that are missing.
     95  std::array<std::set<uint16_t, DescendingSeqNumComp<uint16_t, kFrameIdLength>>,
     96             kMaxTemporalLayers>
     97      missing_frames_for_layer_;
     98 
     99  // Unwrapper used to unwrap VP8/VP9 streams which have their picture id
    100  // specified.
    101  SeqNumUnwrapper<uint16_t, kFrameIdLength> unwrapper_;
    102 
    103  SeqNumUnwrapper<uint8_t> tl0_unwrapper_;
    104 };
    105 
    106 }  // namespace webrtc
    107 
    108 #endif  // MODULES_VIDEO_CODING_RTP_VP9_REF_FINDER_H_