Line data Source code
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_SESSION_INFO_H_
12 : #define WEBRTC_MODULES_VIDEO_CODING_SESSION_INFO_H_
13 :
14 : #include <list>
15 : #include <vector>
16 :
17 : #include "webrtc/modules/include/module_common_types.h"
18 : #include "webrtc/modules/video_coding/include/video_coding.h"
19 : #include "webrtc/modules/video_coding/packet.h"
20 : #include "webrtc/typedefs.h"
21 :
22 : namespace webrtc {
23 : // Used to pass data from jitter buffer to session info.
24 : // This data is then used in determining whether a frame is decodable.
25 : struct FrameData {
26 : int64_t rtt_ms;
27 : float rolling_average_packets_per_frame;
28 : };
29 :
30 0 : class VCMSessionInfo {
31 : public:
32 : VCMSessionInfo();
33 :
34 : void UpdateDataPointers(const uint8_t* old_base_ptr,
35 : const uint8_t* new_base_ptr);
36 : // NACK - Building the NACK lists.
37 : // Build hard NACK list: Zero out all entries in list up to and including
38 : // _lowSeqNum.
39 : int BuildHardNackList(int* seq_num_list,
40 : int seq_num_list_length,
41 : int nack_seq_nums_index);
42 :
43 : // Build soft NACK list: Zero out only a subset of the packets, discard
44 : // empty packets.
45 : int BuildSoftNackList(int* seq_num_list,
46 : int seq_num_list_length,
47 : int nack_seq_nums_index,
48 : int rtt_ms);
49 : void Reset();
50 : int InsertPacket(const VCMPacket& packet,
51 : uint8_t* frame_buffer,
52 : VCMDecodeErrorMode enable_decodable_state,
53 : const FrameData& frame_data);
54 : bool complete() const;
55 : bool decodable() const;
56 :
57 : // Makes the frame decodable. I.e., only contain decodable NALUs. All
58 : // non-decodable NALUs will be deleted and packets will be moved to in
59 : // memory to remove any empty space.
60 : // Returns the number of bytes deleted from the session.
61 : size_t MakeDecodable();
62 :
63 : // Sets decodable_ to false.
64 : // Used by the dual decoder. After the mode is changed to kNoErrors from
65 : // kWithErrors or kSelective errors, any states that have been marked
66 : // decodable and are not complete are marked as non-decodable.
67 : void SetNotDecodableIfIncomplete();
68 :
69 : size_t SessionLength() const;
70 : int NumPackets() const;
71 : bool HaveFirstPacket() const;
72 : bool HaveLastPacket() const;
73 : bool session_nack() const;
74 0 : webrtc::FrameType FrameType() const { return frame_type_; }
75 : int LowSequenceNumber() const;
76 :
77 : // Returns highest sequence number, media or empty.
78 : int HighSequenceNumber() const;
79 : int PictureId() const;
80 : int TemporalId() const;
81 : bool LayerSync() const;
82 : int Tl0PicId() const;
83 : bool NonReference() const;
84 :
85 : std::vector<NaluInfo> GetNaluInfos() const;
86 :
87 : void SetGofInfo(const GofInfoVP9& gof_info, size_t idx);
88 :
89 : // The number of packets discarded because the decoder can't make use of
90 : // them.
91 : int packets_not_decodable() const;
92 :
93 : private:
94 : enum { kMaxVP8Partitions = 9 };
95 :
96 : typedef std::list<VCMPacket> PacketList;
97 : typedef PacketList::iterator PacketIterator;
98 : typedef PacketList::const_iterator PacketIteratorConst;
99 : typedef PacketList::reverse_iterator ReversePacketIterator;
100 :
101 : void InformOfEmptyPacket(uint16_t seq_num);
102 :
103 : // Finds the packet of the beginning of the next VP8 partition. If
104 : // none is found the returned iterator points to |packets_.end()|.
105 : // |it| is expected to point to the last packet of the previous partition,
106 : // or to the first packet of the frame. |packets_skipped| is incremented
107 : // for each packet found which doesn't have the beginning bit set.
108 : PacketIterator FindNextPartitionBeginning(PacketIterator it) const;
109 :
110 : // Returns an iterator pointing to the last packet of the partition pointed to
111 : // by |it|.
112 : PacketIterator FindPartitionEnd(PacketIterator it) const;
113 : static bool InSequence(const PacketIterator& it,
114 : const PacketIterator& prev_it);
115 : size_t InsertBuffer(uint8_t* frame_buffer, PacketIterator packetIterator);
116 : size_t Insert(const uint8_t* buffer,
117 : size_t length,
118 : bool insert_start_code,
119 : uint8_t* frame_buffer);
120 : void ShiftSubsequentPackets(PacketIterator it, int steps_to_shift);
121 : PacketIterator FindNaluEnd(PacketIterator packet_iter) const;
122 : // Deletes the data of all packets between |start| and |end|, inclusively.
123 : // Note that this function doesn't delete the actual packets.
124 : size_t DeletePacketData(PacketIterator start, PacketIterator end);
125 : void UpdateCompleteSession();
126 :
127 : // When enabled, determine if session is decodable, i.e. incomplete but
128 : // would be sent to the decoder.
129 : // Note: definition assumes random loss.
130 : // A frame is defined to be decodable when:
131 : // Round trip time is higher than threshold
132 : // It is not a key frame
133 : // It has the first packet: In VP8 the first packet contains all or part of
134 : // the first partition, which consists of the most relevant information for
135 : // decoding.
136 : // Either more than the upper threshold of the average number of packets per
137 : // frame is present
138 : // or less than the lower threshold of the average number of packets per
139 : // frame is present: suggests a small frame. Such a frame is unlikely
140 : // to contain many motion vectors, so having the first packet will
141 : // likely suffice. Once we have more than the lower threshold of the
142 : // frame, we know that the frame is medium or large-sized.
143 : void UpdateDecodableSession(const FrameData& frame_data);
144 :
145 : // If this session has been NACKed by the jitter buffer.
146 : bool session_nack_;
147 : bool complete_;
148 : bool decodable_;
149 : webrtc::FrameType frame_type_;
150 : // Packets in this frame.
151 : PacketList packets_;
152 : int empty_seq_num_low_;
153 : int empty_seq_num_high_;
154 :
155 : // The following two variables correspond to the first and last media packets
156 : // in a session defined by the first packet flag and the marker bit.
157 : // They are not necessarily equal to the front and back packets, as packets
158 : // may enter out of order.
159 : // TODO(mikhal): Refactor the list to use a map.
160 : int first_packet_seq_num_;
161 : int last_packet_seq_num_;
162 : };
163 :
164 : } // namespace webrtc
165 :
166 : #endif // WEBRTC_MODULES_VIDEO_CODING_SESSION_INFO_H_
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