1 /*
2  *  Copyright (c) 2011 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 WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
12 #define WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
13 
14 #include "webrtc/typedefs.h"
15 
16 namespace webrtc {
17 
18 // Forward declarations
19 class VCMFrameBuffer;
20 class VCMPacket;
21 
22 class VCMDecodingState {
23  public:
24   VCMDecodingState();
25   ~VCMDecodingState();
26   // Check for old frame
27   bool IsOldFrame(const VCMFrameBuffer* frame) const;
28   // Check for old packet
29   bool IsOldPacket(const VCMPacket* packet) const;
30   // Check for frame continuity based on current decoded state. Use best method
31   // possible, i.e. temporal info, picture ID or sequence number.
32   bool ContinuousFrame(const VCMFrameBuffer* frame) const;
33   void SetState(const VCMFrameBuffer* frame);
34   void CopyFrom(const VCMDecodingState& state);
35   bool UpdateEmptyFrame(const VCMFrameBuffer* frame);
36   // Update the sequence number if the timestamp matches current state and the
37   // sequence number is higher than the current one. This accounts for packets
38   // arriving late.
39   void UpdateOldPacket(const VCMPacket* packet);
40   void SetSeqNum(uint16_t new_seq_num);
41   void Reset();
42   uint32_t time_stamp() const;
43   uint16_t sequence_num() const;
44   // Return true if at initial state.
45   bool in_initial_state() const;
46   // Return true when sync is on - decode all layers.
47   bool full_sync() const;
48 
49  private:
50   void UpdateSyncState(const VCMFrameBuffer* frame);
51   // Designated continuity functions
52   bool ContinuousPictureId(int picture_id) const;
53   bool ContinuousSeqNum(uint16_t seq_num) const;
54   bool ContinuousLayer(int temporal_id, int tl0_pic_id) const;
55   bool UsingPictureId(const VCMFrameBuffer* frame) const;
56 
57   // Keep state of last decoded frame.
58   // TODO(mikhal/stefan): create designated classes to handle these types.
59   uint16_t    sequence_num_;
60   uint32_t    time_stamp_;
61   int         picture_id_;
62   int         temporal_id_;
63   int         tl0_pic_id_;
64   bool        full_sync_;  // Sync flag when temporal layers are used.
65   bool        in_initial_state_;
66 };
67 
68 }  // namespace webrtc
69 
70 #endif  // WEBRTC_MODULES_VIDEO_CODING_DECODING_STATE_H_
71