Logic for finding frame references moved from PacketBuffer to new class

webrtc/modules/video_coding/packet_buffer.h

 /*
  *  Copyright (c) 2016 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 WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
 #define WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
 
-#include <array>
-#include <map>
-#include <memory>
-#include <queue>
-#include <set>
-#include <utility>
 #include <vector>
 
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/base/thread_annotations.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/video_coding/packet.h"
+#include "webrtc/modules/video_coding/rtp_frame_reference_finder.h"
 #include "webrtc/modules/video_coding/sequence_number_util.h"
 
 namespace webrtc {
 namespace video_coding {
 
 class FrameObject;
 class RtpFrameObject;
 
 class OnCompleteFrameCallback {
  public:
   virtual ~OnCompleteFrameCallback() {}
   virtual void OnCompleteFrame(std::unique_ptr<FrameObject> frame) = 0;
 };
 
 class PacketBuffer {
  public:
   // Both |start_buffer_size| and |max_buffer_size| must be a power of 2.
   PacketBuffer(size_t start_buffer_size,
                size_t max_buffer_size,
                OnCompleteFrameCallback* frame_callback);
 
   bool InsertPacket(const VCMPacket& packet);
   void ClearTo(uint16_t seq_num);
-  void Flush();
+  void Clear();
 
  private:
-  static const uint16_t kPicIdLength = 1 << 7;
-  static const uint8_t kMaxTemporalLayers = 5;
-  static const int kMaxStashedFrames = 10;
-  static const int kMaxLayerInfo = 10;
-  static const int kMaxNotYetReceivedFrames = 20;
-  static const int kMaxGofSaved = 15;
-
   friend RtpFrameObject;
   // Since we want the packet buffer to be as packet type agnostic
   // as possible we extract only the information needed in order
   // to determine whether a sequence of packets is continuous or not.
   struct ContinuityInfo {
     // The sequence number of the packet.
     uint16_t seq_num = 0;
 
     // If this is the first packet of the frame.
     bool frame_begin = false;
 
     // If this is the last packet of the frame.
     bool frame_end = false;
 
     // If this slot is currently used.
     bool used = false;
 
     // If all its previous packets have been inserted into the packet buffer.
     bool continuous = false;
 
     // If this packet has been used to create a frame already.
     bool frame_created = false;
   };
 
-  // Expand the buffer.
+  // Tries to expand the buffer.
   bool ExpandBufferSize() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Test if all previous packets has arrived for the given sequence number.
   bool IsContinuous(uint16_t seq_num) const EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Test if all packets of a frame has arrived, and if so, creates a frame.
   // May create multiple frames per invocation.
   void FindFrames(uint16_t seq_num) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Copy the bitstream for |frame| to |destination|.
   bool GetBitstream(const RtpFrameObject& frame, uint8_t* destination);
 
+  // Get the packet with sequence number |seq_num|.
+  VCMPacket* GetPacket(uint16_t seq_num);
+
   // Mark all slots used by |frame| as not used.
   void ReturnFrame(RtpFrameObject* frame);
 
-  // Find the references for this frame.
-  void ManageFrame(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Retry finding references for all frames that previously didn't have
-  // all information needed.
-  void RetryStashedFrames() EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Find references for generic frames.
-  void ManageFrameGeneric(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Find references for Vp8 frames
-  void ManageFrameVp8(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Updates all necessary state used to determine frame references
-  // for Vp8 and then calls the |frame_callback| callback with the
-  // completed frame.
-  void CompletedFrameVp8(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Find references for Vp9 frames
-  void ManageFrameVp9(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Unwrap the picture id and the frame references  and then call the
-  // |frame_callback| callback with the completed frame.
-  void CompletedFrameVp9(std::unique_ptr<RtpFrameObject> frame)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Check if we are missing a frame necessary to determine the references
-  // for this frame.
-  bool MissingRequiredFrameVp9(uint16_t picture_id, const GofInfoVP9& gof)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Updates which frames that have been received. If there is a gap,
-  // missing frames will be added to |missing_frames_for_layer_| or
-  // if this is an already missing frame then it will be removed.
-  void FrameReceivedVp9(uint16_t picture_id, const GofInfoVP9& gof)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // Check if there is a frame with the up-switch flag set in the interval
-  // (|pid_ref|, |picture_id|) with temporal layer smaller than |temporal_idx|.
-  bool UpSwitchInIntervalVp9(uint16_t picture_id,
-                             uint8_t temporal_idx,
-                             uint16_t pid_ref) EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
-  // All picture ids are unwrapped to 16 bits.
-  uint16_t UnwrapPictureId(uint16_t picture_id)
-      EXCLUSIVE_LOCKS_REQUIRED(crit_);
-
   rtc::CriticalSection crit_;
 
   // Buffer size_ and max_size_ must always be a power of two.
   size_t size_ GUARDED_BY(crit_);
   const size_t max_size_;
 
   // The fist sequence number currently in the buffer.
   uint16_t first_seq_num_ GUARDED_BY(crit_);
 
   // The last sequence number currently in the buffer.
   uint16_t last_seq_num_ GUARDED_BY(crit_);
 
   // If the packet buffer has received its first packet.
   bool first_packet_received_ GUARDED_BY(crit_);
 
   // Buffer that holds the inserted packets.
   std::vector<VCMPacket> data_buffer_ GUARDED_BY(crit_);
 
   // Buffer that holds the information about which slot that is currently in use
   // and information needed to determine the continuity between packets.
   std::vector<ContinuityInfo> sequence_buffer_ GUARDED_BY(crit_);
 
-  // The callback that is called when a frame has been created and all its
-  // references has been found.
-  OnCompleteFrameCallback* const frame_callback_;
-
-  // Holds the last sequence number of the last frame that has been created
-  // given the last sequence number of a given keyframe.
-  std::map<uint16_t, uint16_t, DescendingSeqNumComp<uint16_t>>
-    last_seq_num_gop_ GUARDED_BY(crit_);
-
-  // Save the last picture id in order to detect when there is a gap in frames
-  // that have not yet been fully received.
-  int last_picture_id_ GUARDED_BY(crit_);
-
-  // The last unwrapped picture id. Used to unwrap the picture id from a length
-  // of |kPicIdLength| to 16 bits.
-  int last_unwrap_ GUARDED_BY(crit_);
-
-  // Frames earlier than the last received frame that have not yet been
-  // fully received.
-  std::set<uint16_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>
-      not_yet_received_frames_ GUARDED_BY(crit_);
-
-  // Frames that have been fully received but didn't have all the information
-  // needed to determine their references.
-  std::queue<std::unique_ptr<RtpFrameObject>> stashed_frames_ GUARDED_BY(crit_);
-
-  // Holds the information about the last completed frame for a given temporal
-  // layer given a Tl0 picture index.
-  std::map<uint8_t,
-           std::array<int16_t, kMaxTemporalLayers>,
-           DescendingSeqNumComp<uint8_t>>
-      layer_info_ GUARDED_BY(crit_);
-
-  // Where the current scalability structure is in the
-  // |scalability_structures_| array.
-  uint8_t current_ss_idx_;
-
-  // Holds received scalability structures.
-  std::array<GofInfoVP9, kMaxGofSaved> scalability_structures_
-      GUARDED_BY(crit_);
-
-  // Holds the picture id and the Gof information for a given TL0 picture index.
-  std::map<uint8_t,
-           std::pair<uint16_t, GofInfoVP9*>,
-           DescendingSeqNumComp<uint8_t>>
-      gof_info_ GUARDED_BY(crit_);
-
-  // Keep track of which picture id and which temporal layer that had the
-  // up switch flag set.
-  std::map<uint16_t, uint8_t> up_switch_ GUARDED_BY(crit_);
-
-  // For every temporal layer, keep a set of which frames that are missing.
-  std::array<std::set<uint16_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>,
-             kMaxTemporalLayers>
-      missing_frames_for_layer_ GUARDED_BY(crit_);
+  // Frames that have received all their packets are handed off to the
+  // |reference_finder_| which finds the dependencies between the frames.
+  RtpFrameReferenceFinder reference_finder_;
 };
 
 }  // namespace video_coding
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_