blob: 4f61f287357e2f0df0cc1ba2cda5523d3750ce5d [file] [log] [blame]
// 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.
#include "base/callback.h"
#include "base/macros.h"
#include "base/threading/thread_checker.h"
#include "media/audio/audio_io.h"
#include "media/base/audio_converter.h"
#include "media/base/audio_parameters.h"
namespace media {
class VirtualAudioInputStream;
// VirtualAudioOutputStream attaches to a VirtualAudioInputStream when Start()
// is called and is used as an audio source. VirtualAudioOutputStream also
// implements an interface so it can be used as an input to AudioConverter so
// that we can get audio frames that match the AudioParameters that
// VirtualAudioInputStream expects.
class MEDIA_EXPORT VirtualAudioOutputStream
: public AudioOutputStream,
public AudioConverter::InputCallback {
// Callback invoked just after VirtualAudioOutputStream is closed.
typedef base::Callback<void(VirtualAudioOutputStream* vaos)>
// Construct an audio loopback pathway to the given |target| (not owned).
// |target| must outlive this instance.
VirtualAudioOutputStream(const AudioParameters& params,
VirtualAudioInputStream* target,
const AfterCloseCallback& after_close_cb);
~VirtualAudioOutputStream() override;
// AudioOutputStream:
bool Open() override;
void Start(AudioSourceCallback* callback) override;
void Stop() override;
void SetVolume(double volume) override;
void GetVolume(double* volume) override;
void Close() override;
// AudioConverter::InputCallback:
double ProvideInput(AudioBus* audio_bus, uint32_t frames_delayed) override;
const AudioParameters params_;
// Pointer to the VirtualAudioInputStream to attach to when Start() is called.
// This pointer should always be valid because VirtualAudioInputStream should
// outlive this class.
VirtualAudioInputStream* const target_input_stream_;
AfterCloseCallback after_close_cb_;
AudioSourceCallback* callback_;
double volume_;
base::ThreadChecker thread_checker_;
} // namespace media