| // Copyright 2017 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. |
| |
| #ifndef MEDIA_AUDIO_AUDIO_SYSTEM_H_ |
| #define MEDIA_AUDIO_AUDIO_SYSTEM_H_ |
| |
| #include <string> |
| |
| #include "base/callback.h" |
| #include "base/optional.h" |
| #include "media/audio/audio_device_description.h" |
| #include "media/base/audio_parameters.h" |
| #include "media/base/media_export.h" |
| |
| namespace media { |
| |
| // Provides asynchronous interface to access audio device information |
| class MEDIA_EXPORT AudioSystem { |
| public: |
| // Replies are sent asynchronously to the thread the calls are issued on. |
| // Instance is bound to the thread it's called on the first time. |
| // Attention! Audio system thread may outlive the client |
| // objects; bind callbacks with care. |
| |
| // Non-empty optional AudioParameters are guaranteed to be valid. |
| // If optional AudioParameters are empty, it means the specified device is not |
| // found. This is best-effort: non-empty parameters do not guarantee existence |
| // of the device. |
| // TODO(olka,tommi): fix all AudioManager implementations to always report |
| // when a device is not found, instead of returning sub parameter values. |
| using OnAudioParamsCallback = |
| base::OnceCallback<void(const base::Optional<AudioParameters>&)>; |
| using OnInputDeviceInfoCallback = |
| base::OnceCallback<void(const base::Optional<AudioParameters>&, |
| const base::Optional<AudioParameters>&, |
| const std::string&)>; |
| |
| using OnBoolCallback = base::OnceCallback<void(bool)>; |
| using OnDeviceDescriptionsCallback = |
| base::OnceCallback<void(AudioDeviceDescriptions)>; |
| using OnDeviceIdCallback = base::OnceCallback<void(const std::string&)>; |
| |
| // The global AudioManager instance must be created prior to that. |
| static std::unique_ptr<AudioSystem> CreateInstance(); |
| |
| virtual ~AudioSystem(); |
| |
| virtual void GetInputStreamParameters(const std::string& device_id, |
| OnAudioParamsCallback on_params_cb) = 0; |
| |
| virtual void GetOutputStreamParameters( |
| const std::string& device_id, |
| OnAudioParamsCallback on_params_cb) = 0; |
| |
| virtual void HasInputDevices(OnBoolCallback on_has_devices_cb) = 0; |
| |
| virtual void HasOutputDevices(OnBoolCallback on_has_devices_cb) = 0; |
| |
| // Replies with device descriptions of input audio devices if |for_input| is |
| // true, and of output audio devices otherwise. |
| virtual void GetDeviceDescriptions( |
| bool for_input, |
| OnDeviceDescriptionsCallback on_descriptions_cb) = 0; |
| |
| // Replies with an empty string if there is no associated output device found. |
| virtual void GetAssociatedOutputDeviceID( |
| const std::string& input_device_id, |
| OnDeviceIdCallback on_device_id_cb) = 0; |
| |
| // Replies with audio parameters for the specified input device and audio |
| // parameters and device ID of the associated output device, if any (otherwise |
| // the associated output device ID is an empty string). |
| virtual void GetInputDeviceInfo( |
| const std::string& input_device_id, |
| OnInputDeviceInfoCallback on_input_device_info_cb) = 0; |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_AUDIO_AUDIO_SYSTEM_H_s |