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 21 namespace media { 22 23 class AudioBus; 24 class AudioManagerWin; 25 26 class 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