| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| // |
| // Implementation of AudioInputStream for Mac OS X using the special AUHAL |
| // input Audio Unit present in OS 10.4 and later. |
| // The AUHAL input Audio Unit is for low-latency audio I/O. |
| // |
| // Overview of operation: |
| // |
| // - An object of AUAudioInputStream is created by the AudioManager |
| // factory: audio_man->MakeAudioInputStream(). |
| // - Next some thread will call Open(), at that point the underlying |
| // AUHAL output Audio Unit is created and configured. |
| // - Then some thread will call Start(sink). |
| // Then the Audio Unit is started which creates its own thread which |
| // periodically will provide the sink with more data as buffers are being |
| // produced/recorded. |
| // - At some point some thread will call Stop(), which we handle by directly |
| // stopping the AUHAL output Audio Unit. |
| // - The same thread that called stop will call Close() where we cleanup |
| // and notify the audio manager, which likely will destroy this object. |
| // |
| // Implementation notes: |
| // |
| // - It is recommended to first acquire the native sample rate of the default |
| // input device and then use the same rate when creating this object. |
| // Use AUAudioInputStream::HardwareSampleRate() to retrieve the sample rate. |
| // - Calling Close() also leads to self destruction. |
| // - The latency consists of two parts: |
| // 1) Hardware latency, which includes Audio Unit latency, audio device |
| // latency; |
| // 2) The delay between the actual recording instant and the time when the |
| // data packet is provided as a callback. |
| // |
| #ifndef MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_ |
| #define MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_ |
| |
| #include <AudioUnit/AudioUnit.h> |
| #include <CoreAudio/CoreAudio.h> |
| #include <map> |
| |
| #include "base/atomicops.h" |
| #include "base/cancelable_callback.h" |
| #include "base/macros.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/threading/thread_checker.h" |
| #include "base/time/time.h" |
| #include "base/timer/timer.h" |
| #include "media/audio/agc_audio_stream.h" |
| #include "media/audio/audio_io.h" |
| #include "media/audio/audio_parameters.h" |
| #include "media/base/audio_block_fifo.h" |
| |
| namespace media { |
| |
| class AudioBus; |
| class AudioManagerMac; |
| class DataBuffer; |
| |
| class MEDIA_EXPORT AUAudioInputStream |
| : public AgcAudioStream<AudioInputStream> { |
| public: |
| // The ctor takes all the usual parameters, plus |manager| which is the |
| // the audio manager who is creating this object. |
| AUAudioInputStream(AudioManagerMac* manager, |
| const AudioParameters& input_params, |
| AudioDeviceID audio_device_id); |
| // The dtor is typically called by the AudioManager only and it is usually |
| // triggered by calling AudioInputStream::Close(). |
| ~AUAudioInputStream() override; |
| |
| // Implementation of AudioInputStream. |
| bool Open() override; |
| void Start(AudioInputCallback* callback) override; |
| void Stop() override; |
| void Close() override; |
| double GetMaxVolume() override; |
| void SetVolume(double volume) override; |
| double GetVolume() override; |
| bool IsMuted() override; |
| |
| // Returns the current hardware sample rate for the default input device. |
| static int HardwareSampleRate(); |
| |
| // Returns true if the audio unit is active/running. |
| // The result is based on the kAudioOutputUnitProperty_IsRunning property |
| // which exists for output units. |
| bool IsRunning(); |
| |
| AudioDeviceID device_id() const { return input_device_id_; } |
| size_t requested_buffer_size() const { return number_of_frames_; } |
| |
| private: |
| static const AudioObjectPropertyAddress kDeviceChangePropertyAddress; |
| |
| // Callback functions called on a real-time priority I/O thread from the audio |
| // unit. These methods are called when recorded audio is available. |
| static OSStatus DataIsAvailable(void* context, |
| AudioUnitRenderActionFlags* flags, |
| const AudioTimeStamp* time_stamp, |
| UInt32 bus_number, |
| UInt32 number_of_frames, |
| AudioBufferList* io_data); |
| OSStatus OnDataIsAvailable(AudioUnitRenderActionFlags* flags, |
| const AudioTimeStamp* time_stamp, |
| UInt32 bus_number, |
| UInt32 number_of_frames); |
| |
| // Pushes recorded data to consumer of the input audio stream. |
| OSStatus Provide(UInt32 number_of_frames, AudioBufferList* io_data, |
| const AudioTimeStamp* time_stamp); |
| |
| // Callback functions called on different system threads from the Core Audio |
| // framework. These methods are called when device properties are changed. |
| static OSStatus OnDevicePropertyChanged( |
| AudioObjectID object_id, |
| UInt32 num_addresses, |
| const AudioObjectPropertyAddress addresses[], |
| void* context); |
| OSStatus DevicePropertyChanged(AudioObjectID object_id, |
| UInt32 num_addresses, |
| const AudioObjectPropertyAddress addresses[]); |
| |
| // Registers OnDevicePropertyChanged() to receive notifications when device |
| // properties changes. |
| void RegisterDeviceChangeListener(); |
| // Stop listening for changes in device properties. |
| void DeRegisterDeviceChangeListener(); |
| |
| // Gets the fixed capture hardware latency and store it during initialization. |
| // Returns 0 if not available. |
| double GetHardwareLatency(); |
| |
| // Gets the current capture delay value. |
| double GetCaptureLatency(const AudioTimeStamp* input_time_stamp); |
| |
| // Gets the number of channels for a stream of audio data. |
| int GetNumberOfChannelsFromStream(); |
| |
| // Issues the OnError() callback to the |sink_|. |
| void HandleError(OSStatus err); |
| |
| // Helper function to check if the volume control is avialable on specific |
| // channel. |
| bool IsVolumeSettableOnChannel(int channel); |
| |
| // Helper methods to set and get atomic |input_callback_is_active_|. |
| void SetInputCallbackIsActive(bool active); |
| bool GetInputCallbackIsActive(); |
| |
| // Checks if a stream was started successfully and the audio unit also starts |
| // to call InputProc() as it should. This method is called once when a timer |
| // expires 5 seconds after calling Start(). |
| void CheckInputStartupSuccess(); |
| |
| // Uninitializes the audio unit if needed. |
| void CloseAudioUnit(); |
| |
| // Adds extra UMA stats when it has been detected that startup failed. |
| void AddHistogramsForFailedStartup(); |
| |
| // Scans the map of all available property changes (notification types) and |
| // filters out some that make sense to add to UMA stats. |
| void AddDevicePropertyChangesToUMA(bool startup_failed); |
| |
| // Verifies that Open(), Start(), Stop() and Close() are all called on the |
| // creating thread which is the main browser thread (CrBrowserMain) on Mac. |
| base::ThreadChecker thread_checker_; |
| |
| // Our creator, the audio manager needs to be notified when we close. |
| AudioManagerMac* const manager_; |
| |
| // Contains the desired number of audio frames in each callback. |
| const size_t number_of_frames_; |
| |
| // The actual I/O buffer size for the input device connected to the active |
| // AUHAL audio unit. |
| size_t io_buffer_frame_size_; |
| |
| // Pointer to the object that will receive the recorded audio samples. |
| AudioInputCallback* sink_; |
| |
| // Structure that holds the desired output format of the stream. |
| // Note that, this format can differ from the device(=input) format. |
| AudioStreamBasicDescription format_; |
| |
| // The special Audio Unit called AUHAL, which allows us to pass audio data |
| // directly from a microphone, through the HAL, and to our application. |
| // The AUHAL also enables selection of non default devices. |
| AudioUnit audio_unit_; |
| |
| // The UID refers to the current input audio device. |
| const AudioDeviceID input_device_id_; |
| |
| // Provides a mechanism for encapsulating one or more buffers of audio data. |
| AudioBufferList audio_buffer_list_; |
| |
| // Temporary storage for recorded data. The InputProc() renders into this |
| // array as soon as a frame of the desired buffer size has been recorded. |
| scoped_ptr<uint8_t[]> audio_data_buffer_; |
| |
| // Fixed capture hardware latency in frames. |
| double hardware_latency_frames_; |
| |
| // The number of channels in each frame of audio data, which is used |
| // when querying the volume of each channel. |
| int number_of_channels_in_frame_; |
| |
| // FIFO used to accumulates recorded data. |
| media::AudioBlockFifo fifo_; |
| |
| // Used to defer Start() to workaround http://crbug.com/160920. |
| base::CancelableClosure deferred_start_cb_; |
| |
| // Contains time of last successful call to AudioUnitRender(). |
| // Initialized first time in Start() and then updated for each valid |
| // audio buffer. Used to detect long error sequences and to take actions |
| // if length of error sequence is above a certain limit. |
| base::TimeTicks last_success_time_; |
| |
| // Is set to true on the internal AUHAL IO thread in the first input callback |
| // after Start() has bee called. |
| base::subtle::Atomic32 input_callback_is_active_; |
| |
| // Timer which triggers CheckInputStartupSuccess() to verify that input |
| // callbacks have started as intended after a successful call to Start(). |
| // This timer lives on the main browser thread. |
| scoped_ptr<base::OneShotTimer> input_callback_timer_; |
| |
| // Set to true if the Start() call was delayed. |
| // See AudioManagerMac::ShouldDeferStreamStart() for details. |
| bool start_was_deferred_; |
| |
| // Set to true if the audio unit's IO buffer was changed when Open() was |
| // called. |
| bool buffer_size_was_changed_; |
| |
| // Set to true once when AudioUnitRender() succeeds for the first time. |
| bool audio_unit_render_has_worked_; |
| |
| // Maps unique representations of device property notification types and |
| // number of times we have been notified about a change in such a type. |
| // While the notifier is active, this member is modified by several different |
| // internal thread. My guess is that a serial dispatch queue is used under |
| // the hood and it executes one task at a time in the order in which they are |
| // added to the queue. The currently executing task runs on a distinct thread |
| // (which can vary from task to task) that is managed by the dispatch queue. |
| // The map is always read on the creating thread but only while the notifier |
| // is disabled, hence no lock is required. |
| std::map<UInt32, int> device_property_changes_map_; |
| |
| // Set to true when we are listening for changes in device properties. |
| // Only touched on the creating thread. |
| bool device_listener_is_active_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AUAudioInputStream); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_AUDIO_MAC_AUDIO_LOW_LATENCY_INPUT_MAC_H_ |