Logic for finding frame references moved from PacketBuffer to new class

webrtc/modules/video_coding/rtp_frame_reference_finder.h

Index: webrtc/modules/video_coding/rtp_frame_reference_finder.h
diff --git a/webrtc/modules/video_coding/packet_buffer.h b/webrtc/modules/video_coding/rtp_frame_reference_finder.h
similarity index 60%
copy from webrtc/modules/video_coding/packet_buffer.h
copy to webrtc/modules/video_coding/rtp_frame_reference_finder.h
index 8a1d7069f4e9e9d275f239553710668f35ab1e62..52eeaed7a8961be8ce2dc8c2eb7b7f0870bdba75 100644
--- a/webrtc/modules/video_coding/packet_buffer.h
+++ b/webrtc/modules/video_coding/rtp_frame_reference_finder.h
@@ -8,98 +8,41 @@
  *  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_
+#ifndef WEBRTC_MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_
+#define WEBRTC_MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_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/sequence_number_util.h"
 
 namespace webrtc {
 namespace video_coding {
 
-class FrameObject;
 class RtpFrameObject;
+class OnCompleteFrameCallback;
 
-class OnCompleteFrameCallback {
+class RtpFrameReferenceFinder {
  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();
+  explicit RtpFrameReferenceFinder(OnCompleteFrameCallback* frame_callback);
+  void ManageFrame(std::unique_ptr<RtpFrameObject> frame);
 
  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 kMaxStashedFrames = 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.
-  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);
-
-  // 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_);
+  rtc::CriticalSection crit_;
 
   // Retry finding references for all frames that previously didn't have
   // all information needed.
@@ -146,39 +89,12 @@ class PacketBuffer {
                              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_;
+  uint16_t UnwrapPictureId(uint16_t picture_id) EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   // 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_);
+  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.
@@ -226,9 +142,11 @@ class PacketBuffer {
   std::array<std::set<uint16_t, DescendingSeqNumComp<uint16_t, kPicIdLength>>,
              kMaxTemporalLayers>
       missing_frames_for_layer_ GUARDED_BY(crit_);
+
+  OnCompleteFrameCallback* frame_callback_;
 };
 
 }  // namespace video_coding
 }  // namespace webrtc
 
-#endif  // WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
+#endif  // WEBRTC_MODULES_VIDEO_CODING_RTP_FRAME_REFERENCE_FINDER_H_