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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