1 /*
2  *  Copyright 2015 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 // This file contains interfaces for RtpReceivers
12 // http://w3c.github.io/webrtc-pc/#rtcrtpreceiver-interface
13 
14 #ifndef API_RTP_RECEIVER_INTERFACE_H_
15 #define API_RTP_RECEIVER_INTERFACE_H_
16 
17 #include <string>
18 #include <vector>
19 
20 #include "api/crypto/frame_decryptor_interface.h"
21 #include "api/dtls_transport_interface.h"
22 #include "api/frame_transformer_interface.h"
23 #include "api/media_stream_interface.h"
24 #include "api/media_types.h"
25 #include "api/proxy.h"
26 #include "api/rtp_parameters.h"
27 #include "api/scoped_refptr.h"
28 #include "api/transport/rtp/rtp_source.h"
29 #include "rtc_base/deprecation.h"
30 #include "rtc_base/ref_count.h"
31 #include "rtc_base/system/rtc_export.h"
32 
33 namespace webrtc {
34 
35 class RtpReceiverObserverInterface {
36  public:
37   // Note: Currently if there are multiple RtpReceivers of the same media type,
38   // they will all call OnFirstPacketReceived at once.
39   //
40   // In the future, it's likely that an RtpReceiver will only call
41   // OnFirstPacketReceived when a packet is received specifically for its
42   // SSRC/mid.
43   virtual void OnFirstPacketReceived(cricket::MediaType media_type) = 0;
44 
45  protected:
~RtpReceiverObserverInterface()46   virtual ~RtpReceiverObserverInterface() {}
47 };
48 
49 class RTC_EXPORT RtpReceiverInterface : public rtc::RefCountInterface {
50  public:
51   virtual rtc::scoped_refptr<MediaStreamTrackInterface> track() const = 0;
52 
53   // The dtlsTransport attribute exposes the DTLS transport on which the
54   // media is received. It may be null.
55   // https://w3c.github.io/webrtc-pc/#dom-rtcrtpreceiver-transport
56   // TODO(https://bugs.webrtc.org/907849) remove default implementation
57   virtual rtc::scoped_refptr<DtlsTransportInterface> dtls_transport() const;
58 
59   // The list of streams that |track| is associated with. This is the same as
60   // the [[AssociatedRemoteMediaStreams]] internal slot in the spec.
61   // https://w3c.github.io/webrtc-pc/#dfn-associatedremotemediastreams
62   // TODO(hbos): Make pure virtual as soon as Chromium's mock implements this.
63   // TODO(https://crbug.com/webrtc/9480): Remove streams() in favor of
64   // stream_ids() as soon as downstream projects are no longer dependent on
65   // stream objects.
66   virtual std::vector<std::string> stream_ids() const;
67   virtual std::vector<rtc::scoped_refptr<MediaStreamInterface>> streams() const;
68 
69   // Audio or video receiver?
70   virtual cricket::MediaType media_type() const = 0;
71 
72   // Not to be confused with "mid", this is a field we can temporarily use
73   // to uniquely identify a receiver until we implement Unified Plan SDP.
74   virtual std::string id() const = 0;
75 
76   // The WebRTC specification only defines RTCRtpParameters in terms of senders,
77   // but this API also applies them to receivers, similar to ORTC:
78   // http://ortc.org/wp-content/uploads/2016/03/ortc.html#rtcrtpparameters*.
79   virtual RtpParameters GetParameters() const = 0;
80   // TODO(dinosaurav): Delete SetParameters entirely after rolling to Chromium.
81   // Currently, doesn't support changing any parameters.
SetParameters(const RtpParameters & parameters)82   virtual bool SetParameters(const RtpParameters& parameters) { return false; }
83 
84   // Does not take ownership of observer.
85   // Must call SetObserver(nullptr) before the observer is destroyed.
86   virtual void SetObserver(RtpReceiverObserverInterface* observer) = 0;
87 
88   // Sets the jitter buffer minimum delay until media playout. Actual observed
89   // delay may differ depending on the congestion control. |delay_seconds| is a
90   // positive value including 0.0 measured in seconds. |nullopt| means default
91   // value must be used.
92   virtual void SetJitterBufferMinimumDelay(
93       absl::optional<double> delay_seconds) = 0;
94 
95   // TODO(zhihuang): Remove the default implementation once the subclasses
96   // implement this. Currently, the only relevant subclass is the
97   // content::FakeRtpReceiver in Chromium.
98   virtual std::vector<RtpSource> GetSources() const;
99 
100   // Sets a user defined frame decryptor that will decrypt the entire frame
101   // before it is sent across the network. This will decrypt the entire frame
102   // using the user provided decryption mechanism regardless of whether SRTP is
103   // enabled or not.
104   virtual void SetFrameDecryptor(
105       rtc::scoped_refptr<FrameDecryptorInterface> frame_decryptor);
106 
107   // Returns a pointer to the frame decryptor set previously by the
108   // user. This can be used to update the state of the object.
109   virtual rtc::scoped_refptr<FrameDecryptorInterface> GetFrameDecryptor() const;
110 
111   // Sets a frame transformer between the depacketizer and the decoder to enable
112   // client code to transform received frames according to their own processing
113   // logic.
114   virtual void SetDepacketizerToDecoderFrameTransformer(
115       rtc::scoped_refptr<FrameTransformerInterface> frame_transformer);
116 
117  protected:
118   ~RtpReceiverInterface() override = default;
119 };
120 
121 // Define proxy for RtpReceiverInterface.
122 // TODO(deadbeef): Move this to .cc file and out of api/. What threads methods
123 // are called on is an implementation detail.
124 BEGIN_SIGNALING_PROXY_MAP(RtpReceiver)
125 PROXY_SIGNALING_THREAD_DESTRUCTOR()
126 PROXY_CONSTMETHOD0(rtc::scoped_refptr<MediaStreamTrackInterface>, track)
127 PROXY_CONSTMETHOD0(rtc::scoped_refptr<DtlsTransportInterface>, dtls_transport)
128 PROXY_CONSTMETHOD0(std::vector<std::string>, stream_ids)
129 PROXY_CONSTMETHOD0(std::vector<rtc::scoped_refptr<MediaStreamInterface>>,
130                    streams)
131 PROXY_CONSTMETHOD0(cricket::MediaType, media_type)
132 PROXY_CONSTMETHOD0(std::string, id)
133 PROXY_CONSTMETHOD0(RtpParameters, GetParameters)
134 PROXY_METHOD1(void, SetObserver, RtpReceiverObserverInterface*)
135 PROXY_METHOD1(void, SetJitterBufferMinimumDelay, absl::optional<double>)
136 PROXY_CONSTMETHOD0(std::vector<RtpSource>, GetSources)
137 PROXY_METHOD1(void,
138               SetFrameDecryptor,
139               rtc::scoped_refptr<FrameDecryptorInterface>)
140 PROXY_CONSTMETHOD0(rtc::scoped_refptr<FrameDecryptorInterface>,
141                    GetFrameDecryptor)
142 PROXY_METHOD1(void,
143               SetDepacketizerToDecoderFrameTransformer,
144               rtc::scoped_refptr<FrameTransformerInterface>)
145 END_PROXY_MAP()
146 
147 }  // namespace webrtc
148 
149 #endif  // API_RTP_RECEIVER_INTERFACE_H_
150