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