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
49 private:
50  enum State {
51    kStateEmpty,      // Initial state.
52    kStateReady,      // Device obtained and ready to record.
53    kStateRecording,  // Recording audio.
54    kStateStopping,   // Trying to stop, waiting for callback to finish.
55    kStateStopped,    // Stopped. Device was reset.
56    kStateClosed      // Device has been released.
57  };
58
59  // Allow unit tests to query the device ID.
60  friend class AudioManagerTest;
61
62  // Windows calls us back with the recorded audio data here. See msdn
63  // documentation for 'waveInProc' for details about the parameters.
64  static void CALLBACK WaveCallback(HWAVEIN hwi, UINT msg, DWORD_PTR instance,
65                                    DWORD_PTR param1, DWORD_PTR param2);
66
67  // If windows reports an error this function handles it and passes it to
68  // the attached AudioInputCallback::OnError().
69  void HandleError(MMRESULT error);
70
71  // Allocates and prepares the memory that will be used for recording.
72  void SetupBuffers();
73
74  // Deallocates the memory allocated in SetupBuffers.
75  void FreeBuffers();
76
77  // Sends a buffer to the audio driver for recording.
78  void QueueNextPacket(WAVEHDR* buffer);
79
80  // Converts the stored device id string into an unsigned integer which
81  // can be used by waveInOpen() to open the specified capture device.
82  bool GetDeviceId(UINT* device_index);
83
84  base::ThreadChecker thread_checker_;
85
86  // Reader beware. Visual C has stronger guarantees on volatile vars than
87  // most people expect. In fact, it has release semantics on write and
88  // acquire semantics on reads. See the msdn documentation.
89  volatile State state_;
90
91  // The audio manager that created this input stream. We notify it when
92  // we close so it can release its own resources.
93  AudioManagerWin* manager_;
94
95  // We use the callback mostly to periodically give the recorded audio data.
96  AudioInputCallback* callback_;
97
98  // The number of buffers of size |buffer_size_| each to use.
99  const int num_buffers_;
100
101  // The size in bytes of each audio buffer.
102  uint32 buffer_size_;
103
104  // Channels, 1 or 2.
105  const int channels_;
106
107  // Contains the unique name of the selected endpoint device.
108  // Note that AudioManagerBase::kDefaultDeviceId represents the default
109  // device role and is not a valid ID as such.
110  std::string device_id_;
111
112  // Windows native structure to encode the format parameters.
113  WAVEFORMATEX format_;
114
115  // Handle to the instance of the wave device.
116  HWAVEIN wavein_;
117
118  // Pointer to the first allocated audio buffer. This object owns it.
119  WAVEHDR* buffer_;
120
121  // An event that is signaled when the callback thread is ready to stop.
122  base::win::ScopedHandle stopped_event_;
123
124  // Lock used to avoid conflicts when Stop() is called during a callback.
125  base::Lock lock_;
126
127  // Extra audio bus used for storage of deinterleaved data for the OnData
128  // callback.
129  scoped_ptr<media::AudioBus> audio_bus_;
130
131  DISALLOW_COPY_AND_ASSIGN(PCMWaveInAudioInputStream);
132};
133
134}  // namespace media
135
136#endif  // MEDIA_AUDIO_WIN_WAVEIN_INPUT_WIN_H_
137