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1 /*
2  * libjingle
3  * Copyright 2012, Google Inc.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  *  1. Redistributions of source code must retain the above copyright notice,
9  *     this list of conditions and the following disclaimer.
10  *  2. Redistributions in binary form must reproduce the above copyright notice,
11  *     this list of conditions and the following disclaimer in the documentation
12  *     and/or other materials provided with the distribution.
13  *  3. The name of the author may not be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
17  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
18  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
19  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 // This file contains interfaces for MediaStream, MediaTrack and MediaSource.
29 // These interfaces are used for implementing MediaStream and MediaTrack as
30 // defined in http://dev.w3.org/2011/webrtc/editor/webrtc.html#stream-api. These
31 // interfaces must be used only with PeerConnection. PeerConnectionManager
32 // interface provides the factory methods to create MediaStream and MediaTracks.
33 
34 #ifndef TALK_APP_WEBRTC_MEDIASTREAMINTERFACE_H_
35 #define TALK_APP_WEBRTC_MEDIASTREAMINTERFACE_H_
36 
37 #include <string>
38 #include <vector>
39 
40 #include "webrtc/base/basictypes.h"
41 #include "webrtc/base/refcount.h"
42 #include "webrtc/base/scoped_ref_ptr.h"
43 
44 namespace cricket {
45 
46 class AudioRenderer;
47 class VideoCapturer;
48 class VideoRenderer;
49 class VideoFrame;
50 
51 }  // namespace cricket
52 
53 namespace webrtc {
54 
55 // Generic observer interface.
56 class ObserverInterface {
57  public:
58   virtual void OnChanged() = 0;
59 
60  protected:
~ObserverInterface()61   virtual ~ObserverInterface() {}
62 };
63 
64 class NotifierInterface {
65  public:
66   virtual void RegisterObserver(ObserverInterface* observer) = 0;
67   virtual void UnregisterObserver(ObserverInterface* observer) = 0;
68 
~NotifierInterface()69   virtual ~NotifierInterface() {}
70 };
71 
72 // Base class for sources. A MediaStreamTrack have an underlying source that
73 // provide media. A source can be shared with multiple tracks.
74 // TODO(perkj): Implement sources for local and remote audio tracks and
75 // remote video tracks.
76 class MediaSourceInterface : public rtc::RefCountInterface,
77                              public NotifierInterface {
78  public:
79   enum SourceState {
80     kInitializing,
81     kLive,
82     kEnded,
83     kMuted
84   };
85 
86   virtual SourceState state() const = 0;
87 
88  protected:
~MediaSourceInterface()89   virtual ~MediaSourceInterface() {}
90 };
91 
92 // Information about a track.
93 class MediaStreamTrackInterface : public rtc::RefCountInterface,
94                                   public NotifierInterface {
95  public:
96   enum TrackState {
97     kInitializing,  // Track is beeing negotiated.
98     kLive = 1,  // Track alive
99     kEnded = 2,  // Track have ended
100     kFailed = 3,  // Track negotiation failed.
101   };
102 
103   virtual std::string kind() const = 0;
104   virtual std::string id() const = 0;
105   virtual bool enabled() const = 0;
106   virtual TrackState state() const = 0;
107   virtual bool set_enabled(bool enable) = 0;
108   // These methods should be called by implementation only.
109   virtual bool set_state(TrackState new_state) = 0;
110 
111  protected:
~MediaStreamTrackInterface()112   virtual ~MediaStreamTrackInterface() {}
113 };
114 
115 // Interface for rendering VideoFrames from a VideoTrack
116 class VideoRendererInterface {
117  public:
118   virtual void SetSize(int width, int height) = 0;
119   virtual void RenderFrame(const cricket::VideoFrame* frame) = 0;
120 
121  protected:
122   // The destructor is protected to prevent deletion via the interface.
123   // This is so that we allow reference counted classes, where the destructor
124   // should never be public, to implement the interface.
~VideoRendererInterface()125   virtual ~VideoRendererInterface() {}
126 };
127 
128 class VideoSourceInterface;
129 
130 class VideoTrackInterface : public MediaStreamTrackInterface {
131  public:
132   // Register a renderer that will render all frames received on this track.
133   virtual void AddRenderer(VideoRendererInterface* renderer) = 0;
134   // Deregister a renderer.
135   virtual void RemoveRenderer(VideoRendererInterface* renderer) = 0;
136 
137   virtual VideoSourceInterface* GetSource() const = 0;
138 
139  protected:
~VideoTrackInterface()140   virtual ~VideoTrackInterface() {}
141 };
142 
143 // AudioSourceInterface is a reference counted source used for AudioTracks.
144 // The same source can be used in multiple AudioTracks.
145 class AudioSourceInterface : public MediaSourceInterface {
146  public:
147   class AudioObserver {
148    public:
149     virtual void OnSetVolume(double volume) = 0;
150 
151    protected:
~AudioObserver()152     virtual ~AudioObserver() {}
153   };
154 
155   // TODO(xians): Makes all the interface pure virtual after Chrome has their
156   // implementations.
157   // Sets the volume to the source. |volume| is in  the range of [0, 10].
SetVolume(double volume)158   virtual void SetVolume(double volume) {}
159 
160   // Registers/unregisters observer to the audio source.
RegisterAudioObserver(AudioObserver * observer)161   virtual void RegisterAudioObserver(AudioObserver* observer) {}
UnregisterAudioObserver(AudioObserver * observer)162   virtual void UnregisterAudioObserver(AudioObserver* observer) {}
163 };
164 
165 // Interface for receiving audio data from a AudioTrack.
166 class AudioTrackSinkInterface {
167  public:
168   virtual void OnData(const void* audio_data,
169                       int bits_per_sample,
170                       int sample_rate,
171                       int number_of_channels,
172                       int number_of_frames) = 0;
173  protected:
~AudioTrackSinkInterface()174   virtual ~AudioTrackSinkInterface() {}
175 };
176 
177 // Interface of the audio processor used by the audio track to collect
178 // statistics.
179 class AudioProcessorInterface : public rtc::RefCountInterface {
180  public:
181   struct AudioProcessorStats {
AudioProcessorStatsAudioProcessorStats182     AudioProcessorStats() : typing_noise_detected(false),
183                             echo_return_loss(0),
184                             echo_return_loss_enhancement(0),
185                             echo_delay_median_ms(0),
186                             aec_quality_min(0.0),
187                             echo_delay_std_ms(0) {}
~AudioProcessorStatsAudioProcessorStats188     ~AudioProcessorStats() {}
189 
190     bool typing_noise_detected;
191     int echo_return_loss;
192     int echo_return_loss_enhancement;
193     int echo_delay_median_ms;
194     float aec_quality_min;
195     int echo_delay_std_ms;
196   };
197 
198   // Get audio processor statistics.
199   virtual void GetStats(AudioProcessorStats* stats) = 0;
200 
201  protected:
~AudioProcessorInterface()202   virtual ~AudioProcessorInterface() {}
203 };
204 
205 class AudioTrackInterface : public MediaStreamTrackInterface {
206  public:
207   // TODO(xians): Figure out if the following interface should be const or not.
208   virtual AudioSourceInterface* GetSource() const =  0;
209 
210   // Add/Remove a sink that will receive the audio data from the track.
211   virtual void AddSink(AudioTrackSinkInterface* sink) = 0;
212   virtual void RemoveSink(AudioTrackSinkInterface* sink) = 0;
213 
214   // Get the signal level from the audio track.
215   // Return true on success, otherwise false.
216   // TODO(xians): Change the interface to int GetSignalLevel() and pure virtual
217   // after Chrome has the correct implementation of the interface.
GetSignalLevel(int * level)218   virtual bool GetSignalLevel(int* level) { return false; }
219 
220   // Get the audio processor used by the audio track. Return NULL if the track
221   // does not have any processor.
222   // TODO(xians): Make the interface pure virtual.
223   virtual rtc::scoped_refptr<AudioProcessorInterface>
GetAudioProcessor()224       GetAudioProcessor() { return NULL; }
225 
226   // Get a pointer to the audio renderer of this AudioTrack.
227   // The pointer is valid for the lifetime of this AudioTrack.
228   // TODO(xians): Remove the following interface after Chrome switches to
229   // AddSink() and RemoveSink() interfaces.
GetRenderer()230   virtual cricket::AudioRenderer* GetRenderer() { return NULL; }
231 
232  protected:
~AudioTrackInterface()233   virtual ~AudioTrackInterface() {}
234 };
235 
236 typedef std::vector<rtc::scoped_refptr<AudioTrackInterface> >
237     AudioTrackVector;
238 typedef std::vector<rtc::scoped_refptr<VideoTrackInterface> >
239     VideoTrackVector;
240 
241 class MediaStreamInterface : public rtc::RefCountInterface,
242                              public NotifierInterface {
243  public:
244   virtual std::string label() const = 0;
245 
246   virtual AudioTrackVector GetAudioTracks() = 0;
247   virtual VideoTrackVector GetVideoTracks() = 0;
248   virtual rtc::scoped_refptr<AudioTrackInterface>
249       FindAudioTrack(const std::string& track_id) = 0;
250   virtual rtc::scoped_refptr<VideoTrackInterface>
251       FindVideoTrack(const std::string& track_id) = 0;
252 
253   virtual bool AddTrack(AudioTrackInterface* track) = 0;
254   virtual bool AddTrack(VideoTrackInterface* track) = 0;
255   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
256   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
257 
258  protected:
~MediaStreamInterface()259   virtual ~MediaStreamInterface() {}
260 };
261 
262 }  // namespace webrtc
263 
264 #endif  // TALK_APP_WEBRTC_MEDIASTREAMINTERFACE_H_
265