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_RECEIVER_STRATEGY_H_
12#define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_RECEIVER_STRATEGY_H_
13
14#include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp.h"
15#include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp_defines.h"
16#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
17#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
18#include "webrtc/system_wrappers/interface/scoped_ptr.h"
19#include "webrtc/typedefs.h"
20
21namespace webrtc {
22
23class TelephoneEventHandler;
24
25// This strategy deals with media-specific RTP packet processing.
26// This class is not thread-safe and must be protected by its caller.
27class RTPReceiverStrategy {
28 public:
29  static RTPReceiverStrategy* CreateVideoStrategy(RtpData* data_callback);
30  static RTPReceiverStrategy* CreateAudioStrategy(
31      int32_t id, RtpData* data_callback,
32      RtpAudioFeedback* incoming_messages_callback);
33
34  virtual ~RTPReceiverStrategy() {}
35
36  // Parses the RTP packet and calls the data callback with the payload data.
37  // Implementations are encouraged to use the provided packet buffer and RTP
38  // header as arguments to the callback; implementations are also allowed to
39  // make changes in the data as necessary. The specific_payload argument
40  // provides audio or video-specific data. The is_first_packet argument is true
41  // if this packet is either the first packet ever or the first in its frame.
42  virtual int32_t ParseRtpPacket(WebRtcRTPHeader* rtp_header,
43                                 const PayloadUnion& specific_payload,
44                                 bool is_red,
45                                 const uint8_t* payload,
46                                 uint16_t payload_length,
47                                 int64_t timestamp_ms,
48                                 bool is_first_packet) = 0;
49
50  virtual TelephoneEventHandler* GetTelephoneEventHandler() = 0;
51
52  // Retrieves the last known applicable frequency.
53  virtual int GetPayloadTypeFrequency() const = 0;
54
55  // Computes the current dead-or-alive state.
56  virtual RTPAliveType ProcessDeadOrAlive(
57      uint16_t last_payload_length) const = 0;
58
59  // Returns true if we should report CSRC changes for this payload type.
60  // TODO(phoglund): should move out of here along with other payload stuff.
61  virtual bool ShouldReportCsrcChanges(uint8_t payload_type) const = 0;
62
63  // Notifies the strategy that we have created a new non-RED payload type in
64  // the payload registry.
65  virtual int32_t OnNewPayloadTypeCreated(
66      const char payloadName[RTP_PAYLOAD_NAME_SIZE],
67      int8_t payloadType,
68      uint32_t frequency) = 0;
69
70  // Invokes the OnInitializeDecoder callback in a media-specific way.
71  virtual int32_t InvokeOnInitializeDecoder(
72      RtpFeedback* callback,
73      int32_t id,
74      int8_t payload_type,
75      const char payload_name[RTP_PAYLOAD_NAME_SIZE],
76      const PayloadUnion& specific_payload) const = 0;
77
78  // Checks if the payload type has changed, and returns whether we should
79  // reset statistics and/or discard this packet.
80  virtual void CheckPayloadChanged(int8_t payload_type,
81                                   PayloadUnion* specific_payload,
82                                   bool* should_reset_statistics,
83                                   bool* should_discard_changes);
84
85  virtual int Energy(uint8_t array_of_energy[kRtpCsrcSize]) const;
86
87  // Stores / retrieves the last media specific payload for later reference.
88  void GetLastMediaSpecificPayload(PayloadUnion* payload) const;
89  void SetLastMediaSpecificPayload(const PayloadUnion& payload);
90
91 protected:
92  // The data callback is where we should send received payload data.
93  // See ParseRtpPacket. This class does not claim ownership of the callback.
94  // Implementations must NOT hold any critical sections while calling the
95  // callback.
96  //
97  // Note: Implementations may call the callback for other reasons than calls
98  // to ParseRtpPacket, for instance if the implementation somehow recovers a
99  // packet.
100  RTPReceiverStrategy(RtpData* data_callback);
101
102  scoped_ptr<CriticalSectionWrapper> crit_sect_;
103  PayloadUnion last_payload_;
104  RtpData* data_callback_;
105};
106}  // namespace webrtc
107
108#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_RECEIVER_STRATEGY_H_
109