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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:
     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 
     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 class MediaSourceInterface : public rtc::RefCountInterface,
     75                              public NotifierInterface {
     76  public:
     77   enum SourceState {
     78     kInitializing,
     79     kLive,
     80     kEnded,
     81     kMuted
     82   };
     83 
     84   virtual SourceState state() const = 0;
     85 
     86   virtual bool remote() const = 0;
     87 
     88  protected:
     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   static const char kAudioKind[];
    104   static const char kVideoKind[];
    105 
    106   virtual std::string kind() const = 0;
    107   virtual std::string id() const = 0;
    108   virtual bool enabled() const = 0;
    109   virtual TrackState state() const = 0;
    110   virtual bool set_enabled(bool enable) = 0;
    111   // These methods should be called by implementation only.
    112   virtual bool set_state(TrackState new_state) = 0;
    113 
    114  protected:
    115   virtual ~MediaStreamTrackInterface() {}
    116 };
    117 
    118 // Interface for rendering VideoFrames from a VideoTrack
    119 class VideoRendererInterface {
    120  public:
    121   // |frame| may have pending rotation. For clients which can't apply rotation,
    122   // |frame|->GetCopyWithRotationApplied() will return a frame that has the
    123   // rotation applied.
    124   virtual void RenderFrame(const cricket::VideoFrame* frame) = 0;
    125 
    126  protected:
    127   // The destructor is protected to prevent deletion via the interface.
    128   // This is so that we allow reference counted classes, where the destructor
    129   // should never be public, to implement the interface.
    130   virtual ~VideoRendererInterface() {}
    131 };
    132 
    133 class VideoSourceInterface;
    134 
    135 class VideoTrackInterface : public MediaStreamTrackInterface {
    136  public:
    137   // Register a renderer that will render all frames received on this track.
    138   virtual void AddRenderer(VideoRendererInterface* renderer) = 0;
    139   // Deregister a renderer.
    140   virtual void RemoveRenderer(VideoRendererInterface* renderer) = 0;
    141 
    142   virtual VideoSourceInterface* GetSource() const = 0;
    143 
    144  protected:
    145   virtual ~VideoTrackInterface() {}
    146 };
    147 
    148 // Interface for receiving audio data from a AudioTrack.
    149 class AudioTrackSinkInterface {
    150  public:
    151   virtual void OnData(const void* audio_data,
    152                       int bits_per_sample,
    153                       int sample_rate,
    154                       size_t number_of_channels,
    155                       size_t number_of_frames) = 0;
    156 
    157  protected:
    158   virtual ~AudioTrackSinkInterface() {}
    159 };
    160 
    161 // AudioSourceInterface is a reference counted source used for AudioTracks.
    162 // The same source can be used in multiple AudioTracks.
    163 class AudioSourceInterface : public MediaSourceInterface {
    164  public:
    165   class AudioObserver {
    166    public:
    167     virtual void OnSetVolume(double volume) = 0;
    168 
    169    protected:
    170     virtual ~AudioObserver() {}
    171   };
    172 
    173   // TODO(xians): Makes all the interface pure virtual after Chrome has their
    174   // implementations.
    175   // Sets the volume to the source. |volume| is in  the range of [0, 10].
    176   // TODO(tommi): This method should be on the track and ideally volume should
    177   // be applied in the track in a way that does not affect clones of the track.
    178   virtual void SetVolume(double volume) {}
    179 
    180   // Registers/unregisters observer to the audio source.
    181   virtual void RegisterAudioObserver(AudioObserver* observer) {}
    182   virtual void UnregisterAudioObserver(AudioObserver* observer) {}
    183 
    184   // TODO(tommi): Make pure virtual.
    185   virtual void AddSink(AudioTrackSinkInterface* sink) {}
    186   virtual void RemoveSink(AudioTrackSinkInterface* sink) {}
    187 };
    188 
    189 // Interface of the audio processor used by the audio track to collect
    190 // statistics.
    191 class AudioProcessorInterface : public rtc::RefCountInterface {
    192  public:
    193   struct AudioProcessorStats {
    194     AudioProcessorStats() : typing_noise_detected(false),
    195                             echo_return_loss(0),
    196                             echo_return_loss_enhancement(0),
    197                             echo_delay_median_ms(0),
    198                             aec_quality_min(0.0),
    199                             echo_delay_std_ms(0) {}
    200     ~AudioProcessorStats() {}
    201 
    202     bool typing_noise_detected;
    203     int echo_return_loss;
    204     int echo_return_loss_enhancement;
    205     int echo_delay_median_ms;
    206     float aec_quality_min;
    207     int echo_delay_std_ms;
    208   };
    209 
    210   // Get audio processor statistics.
    211   virtual void GetStats(AudioProcessorStats* stats) = 0;
    212 
    213  protected:
    214   virtual ~AudioProcessorInterface() {}
    215 };
    216 
    217 class AudioTrackInterface : public MediaStreamTrackInterface {
    218  public:
    219   // TODO(xians): Figure out if the following interface should be const or not.
    220   virtual AudioSourceInterface* GetSource() const =  0;
    221 
    222   // Add/Remove a sink that will receive the audio data from the track.
    223   virtual void AddSink(AudioTrackSinkInterface* sink) = 0;
    224   virtual void RemoveSink(AudioTrackSinkInterface* sink) = 0;
    225 
    226   // Get the signal level from the audio track.
    227   // Return true on success, otherwise false.
    228   // TODO(xians): Change the interface to int GetSignalLevel() and pure virtual
    229   // after Chrome has the correct implementation of the interface.
    230   virtual bool GetSignalLevel(int* level) { return false; }
    231 
    232   // Get the audio processor used by the audio track. Return NULL if the track
    233   // does not have any processor.
    234   // TODO(xians): Make the interface pure virtual.
    235   virtual rtc::scoped_refptr<AudioProcessorInterface>
    236       GetAudioProcessor() { return NULL; }
    237 
    238   // Get a pointer to the audio renderer of this AudioTrack.
    239   // The pointer is valid for the lifetime of this AudioTrack.
    240   // TODO(xians): Remove the following interface after Chrome switches to
    241   // AddSink() and RemoveSink() interfaces.
    242   virtual cricket::AudioRenderer* GetRenderer() { return NULL; }
    243 
    244  protected:
    245   virtual ~AudioTrackInterface() {}
    246 };
    247 
    248 typedef std::vector<rtc::scoped_refptr<AudioTrackInterface> >
    249     AudioTrackVector;
    250 typedef std::vector<rtc::scoped_refptr<VideoTrackInterface> >
    251     VideoTrackVector;
    252 
    253 class MediaStreamInterface : public rtc::RefCountInterface,
    254                              public NotifierInterface {
    255  public:
    256   virtual std::string label() const = 0;
    257 
    258   virtual AudioTrackVector GetAudioTracks() = 0;
    259   virtual VideoTrackVector GetVideoTracks() = 0;
    260   virtual rtc::scoped_refptr<AudioTrackInterface>
    261       FindAudioTrack(const std::string& track_id) = 0;
    262   virtual rtc::scoped_refptr<VideoTrackInterface>
    263       FindVideoTrack(const std::string& track_id) = 0;
    264 
    265   virtual bool AddTrack(AudioTrackInterface* track) = 0;
    266   virtual bool AddTrack(VideoTrackInterface* track) = 0;
    267   virtual bool RemoveTrack(AudioTrackInterface* track) = 0;
    268   virtual bool RemoveTrack(VideoTrackInterface* track) = 0;
    269 
    270  protected:
    271   virtual ~MediaStreamInterface() {}
    272 };
    273 
    274 }  // namespace webrtc
    275 
    276 #endif  // TALK_APP_WEBRTC_MEDIASTREAMINTERFACE_H_
    277