Simplified AudioOutputStream interface.

media/audio/mac/audio_output_mac.h

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_AUDIO_MAC_AUDIO_OUTPUT_MAC_H_
 #define MEDIA_AUDIO_MAC_AUDIO_OUTPUT_MAC_H_
 
 #include <AudioToolbox/AudioFormat.h>
 #include <AudioToolbox/AudioQueue.h>
 
 #include "media/audio/audio_io.h"
 #include "media/audio/audio_parameters.h"
 
 class AudioManagerMac;
 
 // Implementation of AudioOuputStream for Mac OS X using the audio queue service
 // present in OS 10.5 and later. Audioqueue is the successor to the SoundManager
 // services but it is supported in 64 bits.
 class PCMQueueOutAudioOutputStream : public AudioOutputStream {
  public:
   // The ctor takes all the usual parameters, plus |manager| which is the
   // the audio manager who is creating this object.
   PCMQueueOutAudioOutputStream(AudioManagerMac* manager,
                                AudioParameters params);
   // The dtor is typically called by the AudioManager only and it is usually
   // triggered by calling AudioOutputStream::Close().
   virtual ~PCMQueueOutAudioOutputStream();
 
   // Implementation of AudioOutputStream.
-  virtual bool Open(uint32 packet_size);
+  virtual bool Open();
   virtual void Close();
   virtual void Start(AudioSourceCallback* callback);
   virtual void Stop();
   virtual void SetVolume(double volume);
   virtual void GetVolume(double* volume);
 
  private:
   // The audio is double buffered.
   static const uint32 kNumBuffers = 2;
 
   // The OS calls back here when an audio buffer has been processed.
   static void RenderCallback(void* p_this, AudioQueueRef queue,
                              AudioQueueBufferRef buffer);
   // Called when an error occurs.
   void HandleError(OSStatus err);
 
   // Structure that holds the stream format details such as bitrate.
   AudioStreamBasicDescription format_;
   // Handle to the OS audio queue object.
   AudioQueueRef audio_queue_;
   // Array of pointers to the OS managed audio buffers.
   AudioQueueBufferRef buffer_[kNumBuffers];
   // Pointer to the object that will provide the audio samples.
   AudioSourceCallback* source_;
   // Our creator, the audio manager needs to be notified when we close.
   AudioManagerMac* manager_;
+  // Packet size in bytes.
+  uint32 packet_size_;
   // Number of bytes for making a silence buffer.
   int silence_bytes_;
   // Volume level from 0 to 1.
   float volume_;
   // Number of bytes yet to be played in audio buffer.
   uint32 pending_bytes_;
 
   DISALLOW_COPY_AND_ASSIGN(PCMQueueOutAudioOutputStream);
 };
 
 #endif  // MEDIA_AUDIO_MAC_AUDIO_OUTPUT_MAC_H_