audio_input_mac.h revision ab8f6f0bd665d3c1ff476eb06c58c42630e462d4 
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/cancelable_callback.h"
12#include "base/compiler_specific.h"
13#include "base/time/time.h"
14#include "media/audio/audio_io.h"
15#include "media/audio/audio_parameters.h"
16
17namespace media {
18
19class AudioBus;
20class AudioManagerMac;
21
22// Implementation of AudioInputStream for Mac OS X using the audio queue service
23// present in OS 10.5 and later. Design reflects PCMQueueOutAudioOutputStream.
24class PCMQueueInAudioInputStream : public AudioInputStream {
25 public:
26  // Parameters as per AudioManager::MakeAudioInputStream.
27  PCMQueueInAudioInputStream(AudioManagerMac* manager,
28                             const AudioParameters& params);
29  virtual ~PCMQueueInAudioInputStream();
30
31  // Implementation of AudioInputStream.
32  virtual bool Open() OVERRIDE;
33  virtual void Start(AudioInputCallback* callback) OVERRIDE;
34  virtual void Stop() OVERRIDE;
35  virtual void Close() OVERRIDE;
36  virtual double GetMaxVolume() OVERRIDE;
37  virtual void SetVolume(double volume) OVERRIDE;
38  virtual double GetVolume() OVERRIDE;
39  virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
40  virtual bool GetAutomaticGainControl() OVERRIDE;
41  virtual bool IsMuted() OVERRIDE;
42
43 private:
44  // Issue the OnError to |callback_|;
45  void HandleError(OSStatus err);
46
47  // Allocates and prepares the memory that will be used for recording.
48  bool SetupBuffers();
49
50  // Sends a buffer to the audio driver for recording.
51  OSStatus QueueNextBuffer(AudioQueueBufferRef audio_buffer);
52
53  // Callback from OS, delegates to non-static version below.
54  static void HandleInputBufferStatic(
55      void* data,
56      AudioQueueRef audio_queue,
57      AudioQueueBufferRef audio_buffer,
58      const AudioTimeStamp* start_time,
59      UInt32 num_packets,
60      const AudioStreamPacketDescription* desc);
61
62  // Handles callback from OS. Will be called on OS internal thread.
63  void HandleInputBuffer(AudioQueueRef audio_queue,
64                         AudioQueueBufferRef audio_buffer,
65                         const AudioTimeStamp* start_time,
66                         UInt32 num_packets,
67                         const AudioStreamPacketDescription* packet_desc);
68
69  static const int kNumberBuffers = 3;
70
71  // Manager that owns this stream, used for closing down.
72  AudioManagerMac* manager_;
73  // We use the callback mostly to periodically supply the recorded audio data.
74  AudioInputCallback* callback_;
75  // Structure that holds the stream format details such as bitrate.
76  AudioStreamBasicDescription format_;
77  // Handle to the OS audio queue object.
78  AudioQueueRef audio_queue_;
79  // Size of each of the buffers in |audio_buffers_|
80  uint32 buffer_size_bytes_;
81  // True iff Start() has been called successfully.
82  bool started_;
83  // Used to determine if we need to slow down |callback_| calls.
84  base::TimeTicks last_fill_;
85  // Used to defer Start() to workaround http://crbug.com/160920.
86  base::CancelableClosure deferred_start_cb_;
87
88  scoped_ptr<media::AudioBus> audio_bus_;
89
90  DISALLOW_COPY_AND_ASSIGN(PCMQueueInAudioInputStream);
91};
92
93}  // namespace media
94
95#endif  // MEDIA_AUDIO_MAC_AUDIO_INPUT_MAC_H_
96