audio_input_ipc.h revision c2e0dbddbe15c98d52c4786dac06cb8952a8ae6d 
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/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  };
26
27  // Called when an AudioInputController has been created.
28  // The shared memory |handle| points to a memory section that's used to
29  // transfer data between the AudioInputDevice and AudioInputController
30  // objects.  The implementation of OnStreamCreated takes ownership.
31  // The |socket_handle| is used by the AudioInputController to signal
32  // notifications that more data is available and can optionally provide
33  // parameter changes back.  The AudioInputDevice must read from this socket
34  // and process the shared memory whenever data is read from the socket.
35  virtual void OnStreamCreated(base::SharedMemoryHandle handle,
36                               base::SyncSocket::Handle socket_handle,
37                               int length,
38                               int total_segments) = 0;
39
40  // Called when state of an audio stream has changed.
41  virtual void OnStateChanged(State state) = 0;
42
43  // Called when the input stream volume has changed.
44  virtual void OnVolume(double volume) = 0;
45
46  // Called when the AudioInputIPC object is going away and/or when the
47  // IPC channel has been closed and no more IPC requests can be made.
48  // Implementations should delete their owned AudioInputIPC instance
49  // immediately.
50  virtual void OnIPCClosed() = 0;
51
52 protected:
53  virtual ~AudioInputIPCDelegate();
54};
55
56// Provides IPC functionality for an AudioInputIPCDelegate (e.g., an
57// AudioInputDevice).  The implementation should asynchronously deliver the
58// messages to an AudioInputController object (or create one in the case of
59// CreateStream()), that may live in a separate process.
60class MEDIA_EXPORT AudioInputIPC {
61 public:
62  virtual ~AudioInputIPC();
63
64  // Sends a request to create an AudioInputController object in the peer
65  // process, and configures it to use the specified audio |params|.  The
66  // |total_segments| indidates number of equal-lengthed segments in the shared
67  // memory buffer.  Once the stream has been created, the implementation will
68  // notify |delegate| by calling OnStreamCreated().
69  virtual void CreateStream(AudioInputIPCDelegate* delegate,
70                            int session_id,
71                            const AudioParameters& params,
72                            bool automatic_gain_control,
73                            uint32 total_segments) = 0;
74
75  // Corresponds to a call to AudioInputController::Record() on the server side.
76  virtual void RecordStream() = 0;
77
78  // Sets the volume of the audio stream.
79  virtual void SetVolume(double volume) = 0;
80
81  // Closes the audio stream, which should shut down the corresponding
82  // AudioInputController in the peer process.
83  virtual void CloseStream() = 0;
84};
85
86}  // namespace media
87
88#endif  // MEDIA_AUDIO_AUDIO_INPUT_IPC_H_
89