1 // Copyright 2023 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef COMPONENTS_CAPTURE_MODE_AUDIO_CAPTURER_H_
6 #define COMPONENTS_CAPTURE_MODE_AUDIO_CAPTURER_H_
10 #include "base/memory/weak_ptr.h"
11 #include "base/sequence_checker.h"
12 #include "base/strings/string_piece_forward.h"
13 #include "base/time/time.h"
14 #include "components/capture_mode/capture_mode_export.h"
15 #include "media/base/audio_bus.h"
16 #include "media/base/audio_bus_pool.h"
17 #include "media/base/audio_capturer_source.h"
18 #include "media/base/audio_parameters.h"
19 #include "media/mojo/mojom/audio_stream_factory.mojom-forward.h"
20 #include "mojo/public/cpp/bindings/pending_remote.h"
22 namespace capture_mode {
24 // Defines the type of the callback that will be triggered repeatedly by the
25 // audio input device to deliver a stream of buffers containing the captured
26 // audio data. Each call will provide an `audio_bus` and the
27 // `audio_capture_time` when the first frame of that bus was captured.
28 // This callback will be invoked on a worker thread created by the audio input
29 // device (`media::AudioDeviceThread`). The provided `audio_bus` owns its own
31 using OnAudioCapturedCallback =
32 base::RepeatingCallback<void(std::unique_ptr<media::AudioBus> audio_bus,
33 base::TimeTicks audio_capture_time)>;
35 // Defines an audio capturer that can capture an audio input device whose ID is
36 // `device_id`. The provided `audio_stream_factory` will be used so that the
37 // underlying `AudioInputDevice` can communicate with audio service via IPC. The
38 // provided `audio_params` will be used to initialize the underlying audio
39 // capturer. `callback` will be invoked according to the rules specified above.
40 class CAPTURE_MODE_EXPORT AudioCapturer
41 : public media::AudioCapturerSource::CaptureCallback {
43 AudioCapturer(base::StringPiece device_id,
44 mojo::PendingRemote<media::mojom::AudioStreamFactory>
46 const media::AudioParameters& audio_params,
47 OnAudioCapturedCallback callback);
48 AudioCapturer(const AudioCapturer&) = delete;
49 AudioCapturer& operator=(const AudioCapturer&) = delete;
50 ~AudioCapturer() override;
52 // Starts and stops the audio capture.
56 // media::AudioCapturerSource::CaptureCallback:
57 void OnCaptureStarted() override;
58 void Capture(const media::AudioBus* audio_source,
59 base::TimeTicks audio_capture_time,
61 bool key_pressed) override;
62 void OnCaptureError(media::AudioCapturerSource::ErrorCode code,
63 const std::string& message) override;
64 void OnCaptureMuted(bool is_muted) override;
67 // Will be called when the audio bus that we send to the client via
68 // `on_audio_captured_callback_` (which in turn wraps the `backing_audio_bus`)
69 // is destroyed. The `backing_audio_bus` can then be inserted back into the
71 void OnAudioBusDone(std::unique_ptr<media::AudioBus> backing_audio_bus);
73 SEQUENCE_CHECKER(sequence_checker_);
75 scoped_refptr<media::AudioCapturerSource> audio_capturer_;
77 const OnAudioCapturedCallback on_audio_captured_callback_;
79 // An audio bus pool which we use to avoid allocating audio buses on the real-
80 // time audio thread when `Capture()` above is called.
81 media::AudioBusPoolImpl audio_bus_pool_;
83 // This will be initialized in the ctor as a weak ptr to `this`, and will be
84 // used to bind a callback to `OnAudioBusDone()`. The creation of this weak
85 // ptr, its invalidation, and the invocation of the callback bound to
86 // `OnAudioBusDone()` will all be done on the same sequence guarded by the
87 // above `sequence_checker_`.
88 base::WeakPtr<AudioCapturer> weak_ptr_this_;
90 base::WeakPtrFactory<AudioCapturer> weak_ptr_factory_{this};
93 } // namespace capture_mode
95 #endif // COMPONENTS_CAPTURE_MODE_AUDIO_CAPTURER_H_