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      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 MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
      6 #define MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
      7 
      8 #include <AudioToolbox/AudioFormat.h>
      9 #include <AudioToolbox/AudioQueue.h>
     10 
     11 #include "base/compiler_specific.h"
     12 #include "base/time/time.h"
     13 #include "media/audio/audio_io.h"
     14 #include "media/audio/audio_parameters.h"
     15 
     16 namespace media {
     17 
     18 class AudioManagerBase;
     19 
     20 // Implementation of AudioInputStream for Mac OS X using the audio queue service
     21 // present in OS 10.5 and later. Design reflects PCMQueueOutAudioOutputStream.
     22 class PCMQueueInAudioInputStream : public AudioInputStream {
     23  public:
     24   // Parameters as per AudioManager::MakeAudioInputStream.
     25   PCMQueueInAudioInputStream(AudioManagerBase* manager,
     26                              const AudioParameters& params);
     27   virtual ~PCMQueueInAudioInputStream();
     28 
     29   // Implementation of AudioInputStream.
     30   virtual bool Open() OVERRIDE;
     31   virtual void Start(AudioInputCallback* callback) OVERRIDE;
     32   virtual void Stop() OVERRIDE;
     33   virtual void Close() OVERRIDE;
     34   virtual double GetMaxVolume() OVERRIDE;
     35   virtual void SetVolume(double volume) OVERRIDE;
     36   virtual double GetVolume() OVERRIDE;
     37   virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
     38   virtual bool GetAutomaticGainControl() OVERRIDE;
     39 
     40  private:
     41   // Issue the OnError to |callback_|;
     42   void HandleError(OSStatus err);
     43 
     44   // Allocates and prepares the memory that will be used for recording.
     45   bool SetupBuffers();
     46 
     47   // Sends a buffer to the audio driver for recording.
     48   OSStatus QueueNextBuffer(AudioQueueBufferRef audio_buffer);
     49 
     50   // Callback from OS, delegates to non-static version below.
     51   static void HandleInputBufferStatic(
     52       void* data,
     53       AudioQueueRef audio_queue,
     54       AudioQueueBufferRef audio_buffer,
     55       const AudioTimeStamp* start_time,
     56       UInt32 num_packets,
     57       const AudioStreamPacketDescription* desc);
     58 
     59   // Handles callback from OS. Will be called on OS internal thread.
     60   void HandleInputBuffer(AudioQueueRef audio_queue,
     61                          AudioQueueBufferRef audio_buffer,
     62                          const AudioTimeStamp* start_time,
     63                          UInt32 num_packets,
     64                          const AudioStreamPacketDescription* packet_desc);
     65 
     66   static const int kNumberBuffers = 3;
     67 
     68   // Manager that owns this stream, used for closing down.
     69   AudioManagerBase* manager_;
     70   // We use the callback mostly to periodically supply the recorded audio data.
     71   AudioInputCallback* callback_;
     72   // Structure that holds the stream format details such as bitrate.
     73   AudioStreamBasicDescription format_;
     74   // Handle to the OS audio queue object.
     75   AudioQueueRef audio_queue_;
     76   // Size of each of the buffers in |audio_buffers_|
     77   uint32 buffer_size_bytes_;
     78   // True iff Start() has been called successfully.
     79   bool started_;
     80   // Used to determine if we need to slow down |callback_| calls.
     81   base::TimeTicks last_fill_;
     82 
     83   DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
     84 };
     85 
     86 }  // namespace media
     87 
     88 #endif  // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
     89