wavein_input_win.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_WIN_WAVEIN_INPUT_WIN_H_
6#define MEDIA_AUDIO_WIN_WAVEIN_INPUT_WIN_H_
7
8#include <string>
9
10#include <windows.h>
11#include <mmsystem.h>
12
13#include "base/basictypes.h"
14#include "base/compiler_specific.h"
15#include "base/synchronization/lock.h"
16#include "base/threading/thread_checker.h"
17#include "base/win/scoped_handle.h"
18#include "media/audio/audio_io.h"
19#include "media/audio/audio_parameters.h"
20
21namespace media {
22
23class AudioBus;
24class AudioManagerWin;
25
26class PCMWaveInAudioInputStream : public AudioInputStream {
27 public:
28  // The ctor takes all the usual parameters, plus |manager| which is the
29  // the audio manager who is creating this object and |device_id| which
30  // is provided by the operating system.
31  PCMWaveInAudioInputStream(AudioManagerWin* manager,
32                            const AudioParameters& params,
33                            int num_buffers,
34                            const std::string& device_id);
35  virtual ~PCMWaveInAudioInputStream();
36
37  // Implementation of AudioInputStream.
38  virtual bool Open() OVERRIDE;
39  virtual void Start(AudioInputCallback* callback) OVERRIDE;
40  virtual void Stop() OVERRIDE;
41  virtual void Close() OVERRIDE;
42  // TODO(henrika): Add volume support using the Audio Mixer API.
43  virtual double GetMaxVolume() OVERRIDE;
44  virtual void SetVolume(double volume) OVERRIDE;
45  virtual double GetVolume() OVERRIDE;
46  virtual void SetAutomaticGainControl(bool enabled) OVERRIDE;
47  virtual bool GetAutomaticGainControl() OVERRIDE;
48  virtual bool IsMuted() OVERRIDE;
49
50 private:
51  enum State {
52    kStateEmpty,      // Initial state.
53    kStateReady,      // Device obtained and ready to record.
54    kStateRecording,  // Recording audio.
55    kStateStopping,   // Trying to stop, waiting for callback to finish.
56    kStateStopped,    // Stopped. Device was reset.
57    kStateClosed      // Device has been released.
58  };
59
60  // Allow unit tests to query the device ID.
61  friend class AudioManagerTest;
62
63  // Windows calls us back with the recorded audio data here. See msdn
64  // documentation for 'waveInProc' for details about the parameters.
65  static void CALLBACK WaveCallback(HWAVEIN hwi, UINT msg, DWORD_PTR instance,
66                                    DWORD_PTR param1, DWORD_PTR param2);
67
68  // If windows reports an error this function handles it and passes it to
69  // the attached AudioInputCallback::OnError().
70  void HandleError(MMRESULT error);
71
72  // Allocates and prepares the memory that will be used for recording.
73  void SetupBuffers();
74
75  // Deallocates the memory allocated in SetupBuffers.
76  void FreeBuffers();
77
78  // Sends a buffer to the audio driver for recording.
79  void QueueNextPacket(WAVEHDR* buffer);
80
81  // Converts the stored device id string into an unsigned integer which
82  // can be used by waveInOpen() to open the specified capture device.
83  bool GetDeviceId(UINT* device_index);
84
85  base::ThreadChecker thread_checker_;
86
87  // Reader beware. Visual C has stronger guarantees on volatile vars than
88  // most people expect. In fact, it has release semantics on write and
89  // acquire semantics on reads. See the msdn documentation.
90  volatile State state_;
91
92  // The audio manager that created this input stream. We notify it when
93  // we close so it can release its own resources.
94  AudioManagerWin* manager_;
95
96  // We use the callback mostly to periodically give the recorded audio data.
97  AudioInputCallback* callback_;
98
99  // The number of buffers of size |buffer_size_| each to use.
100  const int num_buffers_;
101
102  // The size in bytes of each audio buffer.
103  uint32 buffer_size_;
104
105  // Channels, 1 or 2.
106  const int channels_;
107
108  // Contains the unique name of the selected endpoint device.
109  // Note that AudioManagerBase::kDefaultDeviceId represents the default
110  // device role and is not a valid ID as such.
111  std::string device_id_;
112
113  // Windows native structure to encode the format parameters.
114  WAVEFORMATEX format_;
115
116  // Handle to the instance of the wave device.
117  HWAVEIN wavein_;
118
119  // Pointer to the first allocated audio buffer. This object owns it.
120  WAVEHDR* buffer_;
121
122  // An event that is signaled when the callback thread is ready to stop.
123  base::win::ScopedHandle stopped_event_;
124
125  // Lock used to avoid conflicts when Stop() is called during a callback.
126  base::Lock lock_;
127
128  // Extra audio bus used for storage of deinterleaved data for the OnData
129  // callback.
130  scoped_ptr<media::AudioBus> audio_bus_;
131
132  DISALLOW_COPY_AND_ASSIGN(PCMWaveInAudioInputStream);
133};
134
135}  // namespace media
136
137#endif  // MEDIA_AUDIO_WIN_WAVEIN_INPUT_WIN_H_
138