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_AUDIO_INPUT_IPC_H_
6#define MEDIA_AUDIO_AUDIO_INPUT_IPC_H_
7
8#include "base/memory/shared_memory.h"
9#include "base/sync_socket.h"
10#include "media/audio/audio_parameters.h"
11#include "media/base/media_export.h"
12
13namespace media {
14
15// Contains IPC notifications for the state of the server side
16// (AudioInputController) audio state changes and when an AudioInputController
17// has been created.  Implemented by AudioInputDevice.
18class MEDIA_EXPORT AudioInputIPCDelegate {
19 public:
20  // Valid states for the input stream.
21  enum State {
22    kRecording,
23    kStopped,
24    kError,
25    kStateLast = kError
26  };
27
28  // Called when an AudioInputController has been created.
29  // The shared memory |handle| points to a memory section that's used to
30  // transfer data between the AudioInputDevice and AudioInputController
31  // objects.  The implementation of OnStreamCreated takes ownership.
32  // The |socket_handle| is used by the AudioInputController to signal
33  // notifications that more data is available and can optionally provide
34  // parameter changes back.  The AudioInputDevice must read from this socket
35  // and process the shared memory whenever data is read from the socket.
36  virtual void OnStreamCreated(base::SharedMemoryHandle handle,
37                               base::SyncSocket::Handle socket_handle,
38                               int length,
39                               int total_segments) = 0;
40
41  // Called when state of an audio stream has changed.
42  virtual void OnStateChanged(State state) = 0;
43
44  // Called when the input stream volume has changed.
45  virtual void OnVolume(double volume) = 0;
46
47  // Called when the AudioInputIPC object is going away and/or when the
48  // IPC channel has been closed and no more IPC requests can be made.
49  // Implementations should delete their owned AudioInputIPC instance
50  // immediately.
51  virtual void OnIPCClosed() = 0;
52
53 protected:
54  virtual ~AudioInputIPCDelegate();
55};
56
57// Provides IPC functionality for an AudioInputIPCDelegate (e.g., an
58// AudioInputDevice).  The implementation should asynchronously deliver the
59// messages to an AudioInputController object (or create one in the case of
60// CreateStream()), that may live in a separate process.
61class MEDIA_EXPORT AudioInputIPC {
62 public:
63  virtual ~AudioInputIPC();
64
65  // Sends a request to create an AudioInputController object in the peer
66  // process, and configures it to use the specified audio |params|.  The
67  // |total_segments| indidates number of equal-lengthed segments in the shared
68  // memory buffer.  Once the stream has been created, the implementation will
69  // notify |delegate| by calling OnStreamCreated().
70  virtual void CreateStream(AudioInputIPCDelegate* delegate,
71                            int session_id,
72                            const AudioParameters& params,
73                            bool automatic_gain_control,
74                            uint32 total_segments) = 0;
75
76  // Corresponds to a call to AudioInputController::Record() on the server side.
77  virtual void RecordStream() = 0;
78
79  // Sets the volume of the audio stream.
80  virtual void SetVolume(double volume) = 0;
81
82  // Closes the audio stream, which should shut down the corresponding
83  // AudioInputController in the peer process.
84  virtual void CloseStream() = 0;
85};
86
87}  // namespace media
88
89#endif  // MEDIA_AUDIO_AUDIO_INPUT_IPC_H_
90