1/*
2 *  Copyright (c) 2012 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_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSION_H_
12#define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSION_H_
13
14#include <map>
15
16#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
17#include "webrtc/typedefs.h"
18
19namespace webrtc {
20
21const uint16_t kRtpOneByteHeaderExtensionId = 0xBEDE;
22
23const size_t kRtpOneByteHeaderLength = 4;
24const size_t kTransmissionTimeOffsetLength = 4;
25const size_t kAudioLevelLength = 2;
26const size_t kAbsoluteSendTimeLength = 4;
27const size_t kVideoRotationLength = 2;
28const size_t kTransportSequenceNumberLength = 3;
29
30struct HeaderExtension {
31  explicit HeaderExtension(RTPExtensionType extension_type)
32      : type(extension_type), length(0), active(true) {
33    Init();
34  }
35
36  HeaderExtension(RTPExtensionType extension_type, bool active)
37      : type(extension_type), length(0), active(active) {
38    Init();
39  }
40
41  void Init() {
42    // TODO(solenberg): Create handler classes for header extensions so we can
43    // get rid of switches like these as well as handling code spread out all
44    // over.
45    switch (type) {
46      case kRtpExtensionTransmissionTimeOffset:
47        length = kTransmissionTimeOffsetLength;
48        break;
49      case kRtpExtensionAudioLevel:
50        length = kAudioLevelLength;
51        break;
52      case kRtpExtensionAbsoluteSendTime:
53        length = kAbsoluteSendTimeLength;
54        break;
55      case kRtpExtensionVideoRotation:
56        length = kVideoRotationLength;
57        break;
58      case kRtpExtensionTransportSequenceNumber:
59        length = kTransportSequenceNumberLength;
60        break;
61      default:
62        assert(false);
63    }
64  }
65
66  const RTPExtensionType type;
67  uint8_t length;
68  bool active;
69};
70
71class RtpHeaderExtensionMap {
72 public:
73  RtpHeaderExtensionMap();
74  ~RtpHeaderExtensionMap();
75
76  void Erase();
77
78  int32_t Register(const RTPExtensionType type, const uint8_t id);
79
80  // Active is a concept for a registered rtp header extension which doesn't
81  // take effect yet until being activated. Inactive RTP header extensions do
82  // not take effect and should not be included in size calculations until they
83  // are activated.
84  int32_t RegisterInactive(const RTPExtensionType type, const uint8_t id);
85  bool SetActive(const RTPExtensionType type, bool active);
86
87  int32_t Deregister(const RTPExtensionType type);
88
89  bool IsRegistered(RTPExtensionType type) const;
90
91  int32_t GetType(const uint8_t id, RTPExtensionType* type) const;
92
93  int32_t GetId(const RTPExtensionType type, uint8_t* id) const;
94
95  //
96  // Methods below ignore any inactive rtp header extensions.
97  //
98
99  size_t GetTotalLengthInBytes() const;
100
101  int32_t GetLengthUntilBlockStartInBytes(const RTPExtensionType type) const;
102
103  void GetCopy(RtpHeaderExtensionMap* map) const;
104
105  int32_t Size() const;
106
107  RTPExtensionType First() const;
108
109  RTPExtensionType Next(RTPExtensionType type) const;
110
111 private:
112  int32_t Register(const RTPExtensionType type, const uint8_t id, bool active);
113  std::map<uint8_t, HeaderExtension*> extensionMap_;
114};
115}  // namespace webrtc
116
117#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_HEADER_EXTENSION_H_
118
119