Stashed frames are now retried in a loop rather than recursively.

webrtc/modules/video_coding/rtp_frame_reference_finder.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.
  */
 
@@ skipping 26 matching lines @@
   virtual void OnCompleteFrame(std::unique_ptr<FrameObject> frame) = 0;
 };
 
 class RtpFrameReferenceFinder {
  public:
   explicit RtpFrameReferenceFinder(OnCompleteFrameCallback* frame_callback);
 
   // Manage this frame until:
   //  - We have all information needed to determine its references, after
   //    which |frame_callback_| is called with the completed frame, or
-  //  - We have too many stashed frames (determined by |kMaxStashedFrames)
+  //  - We have too many stashed frames (determined by |kMaxStashedFrames|)
   //    so we drop this frame, or
   //  - It gets cleared by ClearTo, which also means we drop it.
   void ManageFrame(std::unique_ptr<RtpFrameObject> frame);
 
   // Notifies that padding has been received, which the reference finder
   // might need to calculate the references of a frame.
   void PaddingReceived(uint16_t seq_num);
 
   // Clear all stashed frames that include packets older than |seq_num|.
   void ClearTo(uint16_t seq_num);
 
  private:
   static const uint16_t kPicIdLength = 1 << 15;
   static const uint8_t kMaxTemporalLayers = 5;
   static const int kMaxLayerInfo = 50;
   static const int kMaxStashedFrames = 50;
   static const int kMaxNotYetReceivedFrames = 100;
   static const int kMaxGofSaved = 50;
   static const int kMaxPaddingAge = 100;
 
+  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;
   };
 
   rtc::CriticalSection crit_;
 
   // Find the relevant group of pictures and update its "last-picture-id-with
   // padding" sequence number.
   void UpdateLastPictureIdWithPadding(uint16_t seq_num)
       EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
-  // Retry finding references for all frames that previously didn't have
-  // all information needed.
+  // Retry stashed frames until no more complete frames are found.
   void RetryStashedFrames() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
+  FrameDecision ManageFrameInternal(RtpFrameObject* frame)
+      EXCLUSIVE_LOCKS_REQUIRED(crit_);
+
   // Find references for generic frames. If |picture_id| is unspecified
   // then packet sequence numbers will be used to determine the references
   // of the frames.
-  void ManageFrameGeneric(std::unique_ptr<RtpFrameObject> frame,
-                          int picture_id) EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  FrameDecision ManageFrameGeneric(RtpFrameObject* frame, int picture_id)
+      EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Find references for Vp8 frames
-  void ManageFrameVp8(std::unique_ptr<RtpFrameObject> frame)
+  FrameDecision ManageFrameVp8(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)
+  // Updates necessary layer info state used to determine frame references for
+  // Vp8.
+  void UpdateLayerInfoVp8(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)
+  FrameDecision ManageFrameVp9(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 GofInfo& info)
       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, GofInfo* info)
       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_);
 
+  // Unwrap |frame|s picture id and its references to 16 bits.
+  void UnwrapPictureIds(RtpFrameObject* frame) EXCLUSIVE_LOCKS_REQUIRED(crit_);
   // All picture ids are unwrapped to 16 bits.
   uint16_t UnwrapPictureId(uint16_t picture_id) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // Returns true if the frame is old and should be dropped.
   // TODO(philipel): Remove when VP9 PID/TL0 does not jump mid-stream (should be
   //                 around M59).
   bool Vp9PidTl0Fix(const RtpFrameObject& frame,
                     int16_t* picture_id,
                     int16_t* tl0_pic_idx) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
@@ skipping 83 matching lines @@
   int vp9_fix_last_picture_id_ = -1;
   int vp9_fix_pid_offset_ = 0;
   int vp9_fix_last_tl0_pic_idx_ = -1;
   int vp9_fix_tl0_pic_idx_offset_ = 0;
 };
 
 }  // namespace video_coding
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_