remoting/client/audio_player.h

   1 // Copyright (c) 2012 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 REMOTING_CLIENT_AUDIO_PLAYER_H_
   6 #define REMOTING_CLIENT_AUDIO_PLAYER_H_
   7
   8 #include <list>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/synchronization/lock.h"
  12 #include "remoting/proto/audio.pb.h"
  13
  14 namespace remoting {
  15
  16 class AudioPlayer {
  17  public:
  18   virtual ~AudioPlayer();
  19
  20   void ProcessAudioPacket(scoped_ptr<AudioPacket> packet);
  21
  22  protected:
  23   AudioPlayer();
  24
  25   // Return the recommended number of samples to include in a frame.
  26   virtual uint32 GetSamplesPerFrame() = 0;
  27
  28   // Resets the audio player and starts playback.
  29   // Returns true on success.
  30   virtual bool ResetAudioPlayer(AudioPacket::SamplingRate sampling_rate) = 0;
  31
  32   // Function called by the browser when it needs more audio samples.
  33   static void AudioPlayerCallback(void* samples,
  34                                   uint32 buffer_size,
  35                                   void* data);
  36
  37  private:
  38   friend class AudioPlayerTest;
  39
  40   typedef std::list<AudioPacket*> AudioPacketQueue;
  41
  42   void ResetQueue();
  43   void FillWithSamples(void* samples, uint32 buffer_size);
  44
  45   AudioPacket::SamplingRate sampling_rate_;
  46
  47   bool start_failed_;
  48
  49   // Protects |queued_packets_|, |queued_samples_ and |bytes_consumed_|. This is
  50   // necessary to prevent races, because Pepper will call the  callback on a
  51   // separate thread.
  52   base::Lock lock_;
  53
  54   AudioPacketQueue queued_packets_;
  55   int queued_bytes_;
  56
  57   // The number of bytes from |queued_packets_| that have been consumed.
  58   size_t bytes_consumed_;
  59
  60   DISALLOW_COPY_AND_ASSIGN(AudioPlayer);
  61 };
  62
  63 }  // namespace remoting
  64
  65 #endif  // REMOTING_CLIENT_AUDIO_PLAYER_H_