1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ANDROID_HARDWARE_ICAMERA_RECORDING_PROXY_H
18 #define ANDROID_HARDWARE_ICAMERA_RECORDING_PROXY_H
19 
20 #include <vector>
21 #include <binder/IInterface.h>
22 #include <cutils/native_handle.h>
23 #include <utils/RefBase.h>
24 
25 namespace android {
26 
27 class ICameraRecordingProxyListener;
28 class IMemory;
29 class Parcel;
30 
31 /*
32  * The purpose of ICameraRecordingProxy and ICameraRecordingProxyListener is to
33  * allow applications using the camera during recording.
34  *
35  * Camera service allows only one client at a time. Since camcorder application
36  * needs to own the camera to do things like zoom, the media recorder cannot
37  * access the camera directly during recording. So ICameraRecordingProxy is a
38  * proxy of ICamera, which allows the media recorder to start/stop the recording
39  * and release recording frames. ICameraRecordingProxyListener is an interface
40  * that allows the recorder to receive video frames during recording.
41  *
42  * ICameraRecordingProxy
43  *   startRecording()
44  *   stopRecording()
45  *   releaseRecordingFrame()
46  *
47  * ICameraRecordingProxyListener
48  *   dataCallbackTimestamp()
49 
50  * The camcorder app opens the camera and starts the preview. The app passes
51  * ICamera and ICameraRecordingProxy to the media recorder by
52  * MediaRecorder::setCamera(). The recorder uses ICamera to setup the camera in
53  * MediaRecorder::start(). After setup, the recorder disconnects from camera
54  * service. The recorder calls ICameraRecordingProxy::startRecording() and
55  * passes a ICameraRecordingProxyListener to the app. The app connects back to
56  * camera service and starts the recording. The app owns the camera and can do
57  * things like zoom. The media recorder receives the video frames from the
58  * listener and releases them by ICameraRecordingProxy::releaseRecordingFrame.
59  * The recorder calls ICameraRecordingProxy::stopRecording() to stop the
60  * recording.
61  *
62  * The call sequences are as follows:
63  * 1. The app: Camera.unlock().
64  * 2. The app: MediaRecorder.setCamera().
65  * 3. Start recording
66  *    (1) The app: MediaRecorder.start().
67  *    (2) The recorder: ICamera.unlock() and ICamera.disconnect().
68  *    (3) The recorder: ICameraRecordingProxy.startRecording().
69  *    (4) The app: ICamera.reconnect().
70  *    (5) The app: ICamera.startRecording().
71  * 4. During recording
72  *    (1) The recorder: receive frames from ICameraRecordingProxyListener.dataCallbackTimestamp()
73  *    (2) The recorder: release frames by ICameraRecordingProxy.releaseRecordingFrame().
74  * 5. Stop recording
75  *    (1) The app: MediaRecorder.stop()
76  *    (2) The recorder: ICameraRecordingProxy.stopRecording().
77  *    (3) The app: ICamera.stopRecording().
78  */
79 
80 class ICameraRecordingProxy: public IInterface
81 {
82 public:
83     DECLARE_META_INTERFACE(CameraRecordingProxy);
84 
85     virtual status_t        startRecording(const sp<ICameraRecordingProxyListener>& listener) = 0;
86     virtual void            stopRecording() = 0;
87     virtual void            releaseRecordingFrame(const sp<IMemory>& mem) = 0;
88     virtual void            releaseRecordingFrameHandle(native_handle_t *handle) = 0;
89     virtual void            releaseRecordingFrameHandleBatch(
90                                     const std::vector<native_handle_t*>& handles) = 0;
91 };
92 
93 // ----------------------------------------------------------------------------
94 
95 class BnCameraRecordingProxy: public BnInterface<ICameraRecordingProxy>
96 {
97 public:
98     virtual status_t    onTransact( uint32_t code,
99                                     const Parcel& data,
100                                     Parcel* reply,
101                                     uint32_t flags = 0);
102 };
103 
104 }; // namespace android
105 
106 #endif
107