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 #include <utils/String16.h>
26 
27 namespace android {
28 
29 namespace hardware {
30 class ICamera;
31 }
32 
33 class IMemory;
34 class Camera;
35 
36 class CameraSourceTimeLapse : public CameraSource {
37 public:
38     static CameraSourceTimeLapse *CreateFromCamera(
39         const sp<hardware::ICamera> &camera,
40         const sp<ICameraRecordingProxy> &proxy,
41         int32_t cameraId,
42         const String16& clientName,
43         uid_t clientUid,
44         pid_t clientPid,
45         Size videoSize,
46         int32_t videoFrameRate,
47         const sp<IGraphicBufferProducer>& surface,
48         int64_t timeBetweenTimeLapseFrameCaptureUs);
49 
50     virtual ~CameraSourceTimeLapse();
51 
52     // If the frame capture interval is large, read will block for a long time.
53     // Due to the way the mediaRecorder framework works, a stop() call from
54     // mediaRecorder waits until the read returns, causing a long wait for
55     // stop() to return. To avoid this, we can make read() return a copy of the
56     // last read frame with the same time stamp frequently. This keeps the
57     // read() call from blocking too long. Calling this function quickly
58     // captures another frame, keeps its copy, and enables this mode of read()
59     // returning quickly.
60     void startQuickReadReturns();
61 
62 private:
63     // size of the encoded video.
64     int32_t mVideoWidth;
65     int32_t mVideoHeight;
66 
67     // Time between two frames in final video (1/frameRate)
68     int64_t mTimeBetweenTimeLapseVideoFramesUs;
69 
70     // Real timestamp of the last encoded time lapse frame
71     int64_t mLastTimeLapseFrameRealTimestampUs;
72 
73     // Variable set in dataCallbackTimestamp() to help skipCurrentFrame()
74     // to know if current frame needs to be skipped.
75     bool mSkipCurrentFrame;
76 
77     // Lock for accessing mCameraIdle
78     Mutex mCameraIdleLock;
79 
80     // Condition variable to wait on if camera is is not yet idle. Once the
81     // camera gets idle, this variable will be signalled.
82     Condition mCameraIdleCondition;
83 
84     // True if camera is in preview mode and ready for takePicture().
85     // False after a call to takePicture() but before the final compressed
86     // data callback has been called and preview has been restarted.
87     volatile bool mCameraIdle;
88 
89     // True if stop() is waiting for camera to get idle, i.e. for the last
90     // takePicture() to complete. This is needed so that dataCallbackTimestamp()
91     // can return immediately.
92     volatile bool mStopWaitingForIdleCamera;
93 
94     // Lock for accessing quick stop variables.
95     Mutex mQuickStopLock;
96 
97     // mQuickStop is set to true if we use quick read() returns, otherwise it is set
98     // to false. Once in this mode read() return a copy of the last read frame
99     // with the same time stamp. See startQuickReadReturns().
100     volatile bool mQuickStop;
101 
102     // Forces the next frame passed to dataCallbackTimestamp() to be read
103     // as a time lapse frame. Used by startQuickReadReturns() so that the next
104     // frame wakes up any blocking read.
105     volatile bool mForceRead;
106 
107     // Stores a copy of the MediaBuffer read in the last read() call after
108     // mQuickStop was true.
109     MediaBufferBase* mLastReadBufferCopy;
110 
111     // Status code for last read.
112     status_t mLastReadStatus;
113 
114     CameraSourceTimeLapse(
115         const sp<hardware::ICamera> &camera,
116         const sp<ICameraRecordingProxy> &proxy,
117         int32_t cameraId,
118         const String16& clientName,
119         uid_t clientUid,
120         pid_t clientPid,
121         Size videoSize,
122         int32_t videoFrameRate,
123         const sp<IGraphicBufferProducer>& surface,
124         int64_t timeBetweenTimeLapseFrameCaptureUs);
125 
126     // Wrapper over CameraSource::signalBufferReturned() to implement quick stop.
127     // It only handles the case when mLastReadBufferCopy is signalled. Otherwise
128     // it calls the base class' function.
129     virtual void signalBufferReturned(MediaBufferBase* buffer);
130 
131     // Wrapper over CameraSource::read() to implement quick stop.
132     virtual status_t read(MediaBufferBase **buffer, const ReadOptions *options = NULL);
133 
134     // mSkipCurrentFrame is set to true in dataCallbackTimestamp() if the current
135     // frame needs to be skipped and this function just returns the value of mSkipCurrentFrame.
136     virtual bool skipCurrentFrame(int64_t timestampUs);
137 
138     // Process a buffer item received in CameraSource::BufferQueueListener.
139     // This will be called in VIDEO_BUFFER_MODE_BUFFER_QUEUE mode.
140     virtual void processBufferQueueFrame(BufferItem& buffer);
141 
142     // Convenience function to fill mLastReadBufferCopy from the just read
143     // buffer.
144     void fillLastReadBufferCopy(MediaBufferBase& sourceBuffer);
145 
146     // If the passed in size (width x height) is a supported video/preview size,
147     // the function sets the camera's video/preview size to it and returns true.
148     // Otherwise returns false.
149     bool trySettingVideoSize(int32_t width, int32_t height);
150 
151     // When video camera is used for time lapse capture, returns true
152     // until enough time has passed for the next time lapse frame. When
153     // the frame needs to be encoded, it returns false and also modifies
154     // the time stamp to be one frame time ahead of the last encoded
155     // frame's time stamp.
156     bool skipFrameAndModifyTimeStamp(int64_t *timestampUs);
157 
158     // Wrapper to enter threadTimeLapseEntry()
159     static void *ThreadTimeLapseWrapper(void *me);
160 
161     CameraSourceTimeLapse(const CameraSourceTimeLapse &);
162     CameraSourceTimeLapse &operator=(const CameraSourceTimeLapse &);
163 };
164 
165 }  // namespace android
166 
167 #endif  // CAMERA_SOURCE_TIME_LAPSE_H_
168