/include/camera/ICameraRecordingProxy.h

  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 <binder/IInterface.h>
 21#include <utils/RefBase.h>
 22
 23namespace android {
 24
 25class ICameraRecordingProxyListener;
 26class IMemory;
 27class Parcel;
 28
 29/*
 30 * The purpose of ICameraRecordingProxy and ICameraRecordingProxyListener is to
 31 * allow applications using the camera during recording.
 32 *
 33 * Camera service allows only one client at a time. Since camcorder application
 34 * needs to own the camera to do things like zoom, the media recorder cannot
 35 * access the camera directly during recording. So ICameraRecordingProxy is a
 36 * proxy of ICamera, which allows the media recorder to start/stop the recording
 37 * and release recording frames. ICameraRecordingProxyListener is an interface
 38 * that allows the recorder to receive video frames during recording.
 39 *
 40 * ICameraRecordingProxy
 41 *   startRecording()
 42 *   stopRecording()
 43 *   releaseRecordingFrame()
 44 *
 45 * ICameraRecordingProxyListener
 46 *   dataCallbackTimestamp()
 47
 48 * The camcorder app opens the camera and starts the preview. The app passes
 49 * ICamera and ICameraRecordingProxy to the media recorder by
 50 * MediaRecorder::setCamera(). The recorder uses ICamera to setup the camera in
 51 * MediaRecorder::start(). After setup, the recorder disconnects from camera
 52 * service. The recorder calls ICameraRecordingProxy::startRecording() and
 53 * passes a ICameraRecordingProxyListener to the app. The app connects back to
 54 * camera service and starts the recording. The app owns the camera and can do
 55 * things like zoom. The media recorder receives the video frames from the
 56 * listener and releases them by ICameraRecordingProxy::releaseRecordingFrame.
 57 * The recorder calls ICameraRecordingProxy::stopRecording() to stop the
 58 * recording.
 59 *
 60 * The call sequences are as follows:
 61 * 1. The app: Camera.unlock().
 62 * 2. The app: MediaRecorder.setCamera().
 63 * 3. Start recording
 64 *    (1) The app: MediaRecorder.start().
 65 *    (2) The recorder: ICamera.unlock() and ICamera.disconnect().
 66 *    (3) The recorder: ICameraRecordingProxy.startRecording().
 67 *    (4) The app: ICamera.reconnect().
 68 *    (5) The app: ICamera.startRecording().
 69 * 4. During recording
 70 *    (1) The recorder: receive frames from ICameraRecordingProxyListener.dataCallbackTimestamp()
 71 *    (2) The recorder: release frames by ICameraRecordingProxy.releaseRecordingFrame().
 72 * 5. Stop recording
 73 *    (1) The app: MediaRecorder.stop()
 74 *    (2) The recorder: ICameraRecordingProxy.stopRecording().
 75 *    (3) The app: ICamera.stopRecording().
 76 */
 77
 78class ICameraRecordingProxy: public IInterface
 79{
 80public:
 81    DECLARE_META_INTERFACE(CameraRecordingProxy);
 82
 83    virtual status_t        startRecording(const sp<ICameraRecordingProxyListener>& listener) = 0;
 84    virtual void            stopRecording() = 0;
 85    virtual void            releaseRecordingFrame(const sp<IMemory>& mem) = 0;
 86};
 87
 88// ----------------------------------------------------------------------------
 89
 90class BnCameraRecordingProxy: public BnInterface<ICameraRecordingProxy>
 91{
 92public:
 93    virtual status_t    onTransact( uint32_t code,
 94                                    const Parcel& data,
 95                                    Parcel* reply,
 96                                    uint32_t flags = 0);
 97};
 98
 99}; // namespace android
100
101#endif