media/cast/sender/audio_sender.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_CAST_SENDER_AUDIO_SENDER_H_
   6 #define MEDIA_CAST_SENDER_AUDIO_SENDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/threading/non_thread_safe.h"
  13 #include "base/time/tick_clock.h"
  14 #include "base/time/time.h"
  15 #include "media/base/audio_bus.h"
  16 #include "media/cast/cast_config.h"
  17 #include "media/cast/sender/frame_sender.h"
  18
  19 namespace media {
  20 namespace cast {
  21
  22 class AudioEncoder;
  23
  24 // Not thread safe. Only called from the main cast thread.
  25 // This class owns all objects related to sending audio, objects that create RTP
  26 // packets, congestion control, audio encoder, parsing and sending of
  27 // RTCP packets.
  28 // Additionally it posts a bunch of delayed tasks to the main thread for various
  29 // timeouts.
  30 class AudioSender : public FrameSender,
  31                     public base::NonThreadSafe,
  32                     public base::SupportsWeakPtr<AudioSender> {
  33  public:
  34   AudioSender(scoped_refptr<CastEnvironment> cast_environment,
  35               const AudioSenderConfig& audio_config,
  36               CastTransportSender* const transport_sender);
  37
  38   virtual ~AudioSender();
  39
  40   CastInitializationStatus InitializationResult() const {
  41     return cast_initialization_status_;
  42   }
  43
  44   // Note: It is not guaranteed that |audio_frame| will actually be encoded and
  45   // sent, if AudioSender detects too many frames in flight.  Therefore, clients
  46   // should be careful about the rate at which this method is called.
  47   //
  48   // Note: It is invalid to call this method if InitializationResult() returns
  49   // anything but STATUS_AUDIO_INITIALIZED.
  50   void InsertAudio(scoped_ptr<AudioBus> audio_bus,
  51                    const base::TimeTicks& recorded_time);
  52
  53  protected:
  54   // Protected for testability.
  55   void OnReceivedCastFeedback(const RtcpCastMessage& cast_feedback);
  56
  57  private:
  58   // Returns true if there are too many frames in flight, or if the media
  59   // duration of the frames in flight would be too high by sending the next
  60   // frame.  The latter metric is determined from the given |capture_time|
  61   // for the next frame to be encoded and sent.
  62   bool ShouldDropNextFrame(base::TimeTicks capture_time) const;
  63
  64   // Called by the |audio_encoder_| with the next EncodedFrame to send.
  65   void SendEncodedAudioFrame(scoped_ptr<EncodedFrame> audio_frame);
  66
  67   // Encodes AudioBuses into EncodedFrames.
  68   scoped_ptr<AudioEncoder> audio_encoder_;
  69   const int configured_encoder_bitrate_;
  70
  71   // NOTE: Weak pointers must be invalidated before all other member variables.
  72   base::WeakPtrFactory<AudioSender> weak_factory_;
  73
  74   DISALLOW_COPY_AND_ASSIGN(AudioSender);
  75 };
  76
  77 }  // namespace cast
  78 }  // namespace media
  79
  80 #endif  // MEDIA_CAST_SENDER_AUDIO_SENDER_H_