audio_input_mac.h revision 7d4cd473f85ac64c3747c96c277f9e506a0d2246 
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/AudioQueue.h>
9#include <AudioToolbox/AudioFormat.h>
10
11#include "base/compiler_specific.h"
12#include "base/time.h"
13#include "media/audio/audio_io.h"
14#include "media/audio/audio_parameters.h"
15
16namespace media {
17
18class 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.
22class 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