Work on flexible mode and screen sharing.

webrtc/modules/video_coding/main/source/decoding_state.h

 /*
  *  Copyright (c) 2011 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_DECODING_STATE_H_
 #define WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
 
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Forward declarations
 class VCMFrameBuffer;
 class VCMPacket;
 
 class VCMDecodingState {
  public:
+  // The max number of bits used to reference back
+  // to a previous frame when using flexible mode.
+  static const uint16_t kNumRefBits = 7;
+  static const uint16_t kFrameDecodedLength = 1 << kNumRefBits;
+
   VCMDecodingState();
   ~VCMDecodingState();
   // Check for old frame
   bool IsOldFrame(const VCMFrameBuffer* frame) const;
   // Check for old packet
   bool IsOldPacket(const VCMPacket* packet) const;
   // Check for frame continuity based on current decoded state. Use best method
   // possible, i.e. temporal info, picture ID or sequence number.
   bool ContinuousFrame(const VCMFrameBuffer* frame) const;
   void SetState(const VCMFrameBuffer* frame);
@@ skipping 11 matching lines @@
   bool in_initial_state() const;
   // Return true when sync is on - decode all layers.
   bool full_sync() const;
 
  private:
   void UpdateSyncState(const VCMFrameBuffer* frame);
   // Designated continuity functions
   bool ContinuousPictureId(int picture_id) const;
   bool ContinuousSeqNum(uint16_t seq_num) const;
   bool ContinuousLayer(int temporal_id, int tl0_pic_id) const;
+  bool ContinuousFrameRefs(const VCMFrameBuffer* frame) const;
   bool UsingPictureId(const VCMFrameBuffer* frame) const;
+  bool UsingFlexibleMode(const VCMFrameBuffer* frame) const;
+  bool AheadOfFramesDecodedClearedTo(uint16_t index) const;
 
   // Keep state of last decoded frame.
   // TODO(mikhal/stefan): create designated classes to handle these types.
   uint16_t    sequence_num_;
   uint32_t    time_stamp_;
   int         picture_id_;
   int         temporal_id_;
   int         tl0_pic_id_;
   bool        full_sync_;  // Sync flag when temporal layers are used.
   bool        in_initial_state_;
+
+  // Used to check references in flexible mode.
+  bool frame_decoded_[kFrameDecodedLength];
+  uint16_t frame_decoded_cleared_to_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_