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 <queue> 21 22 #include "ui/GraphicBuffer.h" 23 24 #include <android/hardware/automotive/evs/1.0/IEvsCameraStream.h> 25 #include <android/hardware/automotive/evs/1.0/IEvsCamera.h> 26 #include <android/hardware/automotive/evs/1.0/IEvsDisplay.h> 27 28 using namespace ::android::hardware::automotive::evs::V1_0; 29 using ::android::hardware::Return; 30 using ::android::hardware::Void; 31 using ::android::hardware::hidl_vec; 32 using ::android::hardware::hidl_handle; 33 using ::android::sp; 34 35 36 /* 37 * StreamHandler: 38 * This class can be used to receive camera imagery from an IEvsCamera implementation. It will 39 * hold onto the most recent image buffer, returning older ones. 40 * Note that the video frames are delivered on a background thread, while the control interface 41 * is actuated from the applications foreground thread. 42 */ 43 class StreamHandler : public IEvsCameraStream { 44 public: ~StreamHandler()45 virtual ~StreamHandler() { shutdown(); }; 46 47 StreamHandler(android::sp <IEvsCamera> pCamera); 48 void shutdown(); 49 50 bool startStream(); 51 void asyncStopStream(); 52 void blockingStopStream(); 53 54 bool isRunning(); 55 56 bool newFrameAvailable(); 57 const BufferDesc& getNewFrame(); 58 void doneWithFrame(const BufferDesc& buffer); 59 60 private: 61 // Implementation for ::android::hardware::automotive::evs::V1_0::ICarCameraStream 62 Return<void> deliverFrame(const BufferDesc& buffer) override; 63 64 // Values initialized as startup 65 android::sp <IEvsCamera> mCamera; 66 67 // Since we get frames delivered to us asnchronously via the ICarCameraStream interface, 68 // we need to protect all member variables that may be modified while we're streaming 69 // (ie: those below) 70 std::mutex mLock; 71 std::condition_variable mSignal; 72 73 bool mRunning = false; 74 75 BufferDesc mBuffers[2]; 76 int mHeldBuffer = -1; // Index of the one currently held by the client 77 int mReadyBuffer = -1; // Index of the newest available buffer 78 }; 79 80 81 #endif //EVS_VTS_STREAMHANDLER_H 82