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1 /*
2  * Copyright (C) 2017 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 EVS_VTS_STREAMHANDLER_H
18 #define EVS_VTS_STREAMHANDLER_H
19 
20 #include <aidl/android/hardware/automotive/evs/BnEvsCameraStream.h>
21 #include <aidl/android/hardware/automotive/evs/BufferDesc.h>
22 #include <aidl/android/hardware/automotive/evs/DisplayState.h>
23 #include <aidl/android/hardware/automotive/evs/EvsEventDesc.h>
24 #include <aidl/android/hardware/automotive/evs/IEvsCamera.h>
25 #include <aidl/android/hardware/graphics/common/HardwareBuffer.h>
26 #include <ui/GraphicBuffer.h>
27 
28 #include <queue>
29 
30 /*
31  * StreamHandler:
32  * This class can be used to receive camera imagery from an IEvsCamera implementation.  It will
33  * hold onto the most recent image buffer, returning older ones.
34  * Note that the video frames are delivered on a background thread, while the control interface
35  * is actuated from the applications foreground thread.
36  */
37 class StreamHandler final : public aidl::android::hardware::automotive::evs::BnEvsCameraStream {
38 public:
~StreamHandler()39     virtual ~StreamHandler() { shutdown(); };
40 
41     StreamHandler(
42             const std::shared_ptr<aidl::android::hardware::automotive::evs::IEvsCamera>& cameraObj,
43             uint32_t numBuffers = 2, bool useOwnBuffers = false,
44             android_pixel_format_t format = HAL_PIXEL_FORMAT_RGBA_8888, int32_t width = 640,
45             int32_t height = 360);
46     void shutdown();
47 
48     bool startStream();
49     void asyncStopStream();
50     void blockingStopStream();
51 
52     bool isRunning();
53 
54     bool newFrameAvailable();
55     const aidl::android::hardware::automotive::evs::BufferDesc& getNewFrame();
56     void doneWithFrame(const aidl::android::hardware::automotive::evs::BufferDesc& buffer);
57 
58 private:
59     // Implementation for aidl::android::hardware::automotive::evs::IEvsCameraStream
60     ndk::ScopedAStatus deliverFrame(
61             const std::vector<aidl::android::hardware::automotive::evs::BufferDesc>& buffers)
62             override;
63     ndk::ScopedAStatus notify(
64             const aidl::android::hardware::automotive::evs::EvsEventDesc& event) override;
65 
66     // Values initialized as startup
67     std::shared_ptr<aidl::android::hardware::automotive::evs::IEvsCamera> mCamera;
68 
69     // Since we get frames delivered to us asnchronously via the IEvsCameraStream interface,
70     // we need to protect all member variables that may be modified while we're streaming
71     // (i.e.: those below)
72     std::mutex mLock;
73     std::condition_variable mSignal;
74 
75     bool mRunning = false;
76 
77     aidl::android::hardware::automotive::evs::BufferDesc mBuffers[2];
78     int mHeldBuffer = -1;   // Index of the one currently held by the client
79     int mReadyBuffer = -1;  // Index of the newest available buffer
80     std::vector<aidl::android::hardware::automotive::evs::BufferDesc> mOwnBuffers;
81     bool mUseOwnBuffers;
82 };
83 
84 #endif  // EVS_VTS_STREAMHANDLER_H
85