CameraSourceTimeLapse.h revision e8e5f86e9e310b065596c8cbbca1543eb833dee1 
1/*
2 * Copyright (C) 2010 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 CAMERA_SOURCE_TIME_LAPSE_H_
18
19#define CAMERA_SOURCE_TIME_LAPSE_H_
20
21#include <pthread.h>
22
23#include <utils/RefBase.h>
24#include <utils/threads.h>
25
26namespace android {
27
28class ICamera;
29class IMemory;
30class Camera;
31
32class CameraSourceTimeLapse : public CameraSource {
33public:
34    static CameraSourceTimeLapse *CreateFromCamera(
35        const sp<ICamera> &camera,
36        const sp<ICameraRecordingProxy> &proxy,
37        int32_t cameraId,
38        Size videoSize,
39        int32_t videoFrameRate,
40        const sp<Surface>& surface,
41        int64_t timeBetweenTimeLapseFrameCaptureUs);
42
43    virtual ~CameraSourceTimeLapse();
44
45    // If the frame capture interval is large, read will block for a long time.
46    // Due to the way the mediaRecorder framework works, a stop() call from
47    // mediaRecorder waits until the read returns, causing a long wait for
48    // stop() to return. To avoid this, we can make read() return a copy of the
49    // last read frame with the same time stamp frequently. This keeps the
50    // read() call from blocking too long. Calling this function quickly
51    // captures another frame, keeps its copy, and enables this mode of read()
52    // returning quickly.
53    void startQuickReadReturns();
54
55private:
56    // size of the encoded video.
57    int32_t mVideoWidth;
58    int32_t mVideoHeight;
59
60    // Time between two frames in final video (1/frameRate)
61    int64_t mTimeBetweenTimeLapseVideoFramesUs;
62
63    // Real timestamp of the last encoded time lapse frame
64    int64_t mLastTimeLapseFrameRealTimestampUs;
65
66    // Variable set in dataCallbackTimestamp() to help skipCurrentFrame()
67    // to know if current frame needs to be skipped.
68    bool mSkipCurrentFrame;
69
70    // Lock for accessing mCameraIdle
71    Mutex mCameraIdleLock;
72
73    // Condition variable to wait on if camera is is not yet idle. Once the
74    // camera gets idle, this variable will be signalled.
75    Condition mCameraIdleCondition;
76
77    // True if camera is in preview mode and ready for takePicture().
78    // False after a call to takePicture() but before the final compressed
79    // data callback has been called and preview has been restarted.
80    volatile bool mCameraIdle;
81
82    // True if stop() is waiting for camera to get idle, i.e. for the last
83    // takePicture() to complete. This is needed so that dataCallbackTimestamp()
84    // can return immediately.
85    volatile bool mStopWaitingForIdleCamera;
86
87    // Lock for accessing quick stop variables.
88    Mutex mQuickStopLock;
89
90    // mQuickStop is set to true if we use quick read() returns, otherwise it is set
91    // to false. Once in this mode read() return a copy of the last read frame
92    // with the same time stamp. See startQuickReadReturns().
93    volatile bool mQuickStop;
94
95    // Forces the next frame passed to dataCallbackTimestamp() to be read
96    // as a time lapse frame. Used by startQuickReadReturns() so that the next
97    // frame wakes up any blocking read.
98    volatile bool mForceRead;
99
100    // Stores a copy of the MediaBuffer read in the last read() call after
101    // mQuickStop was true.
102    MediaBuffer* mLastReadBufferCopy;
103
104    // Status code for last read.
105    status_t mLastReadStatus;
106
107    CameraSourceTimeLapse(
108        const sp<ICamera> &camera,
109        const sp<ICameraRecordingProxy> &proxy,
110        int32_t cameraId,
111        Size videoSize,
112        int32_t videoFrameRate,
113        const sp<Surface>& surface,
114        int64_t timeBetweenTimeLapseFrameCaptureUs);
115
116    // Wrapper over CameraSource::signalBufferReturned() to implement quick stop.
117    // It only handles the case when mLastReadBufferCopy is signalled. Otherwise
118    // it calls the base class' function.
119    virtual void signalBufferReturned(MediaBuffer* buffer);
120
121    // Wrapper over CameraSource::read() to implement quick stop.
122    virtual status_t read(MediaBuffer **buffer, const ReadOptions *options = NULL);
123
124    // For video camera case, just stops the camera's video recording.
125    virtual void stopCameraRecording();
126
127    // mSkipCurrentFrame is set to true in dataCallbackTimestamp() if the current
128    // frame needs to be skipped and this function just returns the value of mSkipCurrentFrame.
129    virtual bool skipCurrentFrame(int64_t timestampUs);
130
131    // In the video camera case calls skipFrameAndModifyTimeStamp() to modify
132    // timestamp and set mSkipCurrentFrame.
133    // Then it calls the base CameraSource::dataCallbackTimestamp()
134    virtual void dataCallbackTimestamp(int64_t timestampUs, int32_t msgType,
135            const sp<IMemory> &data);
136
137    // Convenience function to fill mLastReadBufferCopy from the just read
138    // buffer.
139    void fillLastReadBufferCopy(MediaBuffer& sourceBuffer);
140
141    // If the passed in size (width x height) is a supported video/preview size,
142    // the function sets the camera's video/preview size to it and returns true.
143    // Otherwise returns false.
144    bool trySettingVideoSize(int32_t width, int32_t height);
145
146    // When video camera is used for time lapse capture, returns true
147    // until enough time has passed for the next time lapse frame. When
148    // the frame needs to be encoded, it returns false and also modifies
149    // the time stamp to be one frame time ahead of the last encoded
150    // frame's time stamp.
151    bool skipFrameAndModifyTimeStamp(int64_t *timestampUs);
152
153    // Wrapper to enter threadTimeLapseEntry()
154    static void *ThreadTimeLapseWrapper(void *me);
155
156    // Creates a copy of source_data into a new memory of final type MemoryBase.
157    sp<IMemory> createIMemoryCopy(const sp<IMemory> &source_data);
158
159    CameraSourceTimeLapse(const CameraSourceTimeLapse &);
160    CameraSourceTimeLapse &operator=(const CameraSourceTimeLapse &);
161};
162
163}  // namespace android
164
165#endif  // CAMERA_SOURCE_TIME_LAPSE_H_
166