1 /* 2 * Copyright (C) 2016 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 // Loosely based on hardware/libhardware/modules/camera/ExampleCamera.h 18 19 #ifndef V4L2_CAMERA_HAL_V4L2_CAMERA_H_ 20 #define V4L2_CAMERA_HAL_V4L2_CAMERA_H_ 21 22 #include <array> 23 #include <condition_variable> 24 #include <map> 25 #include <queue> 26 #include <string> 27 28 #include <camera/CameraMetadata.h> 29 #include <utils/StrongPointer.h> 30 #include <utils/Thread.h> 31 32 #include "camera.h" 33 #include "common.h" 34 #include "metadata/metadata.h" 35 #include "v4l2_wrapper.h" 36 37 namespace v4l2_camera_hal { 38 // V4L2Camera is a specific V4L2-supported camera device. The Camera object 39 // contains all logic common between all cameras (e.g. front and back cameras), 40 // while a specific camera device (e.g. V4L2Camera) holds all specific 41 // metadata and logic about that device. 42 class V4L2Camera : public default_camera_hal::Camera { 43 public: 44 // Use this method to create V4L2Camera objects. Functionally equivalent 45 // to "new V4L2Camera", except that it may return nullptr in case of failure. 46 static V4L2Camera* NewV4L2Camera(int id, const std::string path); 47 ~V4L2Camera(); 48 49 private: 50 // Constructor private to allow failing on bad input. 51 // Use NewV4L2Camera instead. 52 V4L2Camera(int id, 53 std::shared_ptr<V4L2Wrapper> v4l2_wrapper, 54 std::unique_ptr<Metadata> metadata); 55 56 // default_camera_hal::Camera virtual methods. 57 // Connect to the device: open dev nodes, etc. 58 int connect() override; 59 // Disconnect from the device: close dev nodes, etc. 60 void disconnect() override; 61 // Initialize static camera characteristics for individual device. 62 int initStaticInfo(android::CameraMetadata* out) override; 63 // Initialize a template of the given type. 64 int initTemplate(int type, android::CameraMetadata* out) override; 65 // Initialize device info: resource cost and conflicting devices 66 // (/conflicting devices length). 67 void initDeviceInfo(camera_info_t* info) override; 68 // Extra initialization of device when opened. 69 int initDevice() override; 70 // Verify stream configuration dataspaces and rotation values 71 bool validateDataspacesAndRotations( 72 const camera3_stream_configuration_t* stream_config) override; 73 // Set up the streams, including seting usage & max_buffers 74 int setupStreams(camera3_stream_configuration_t* stream_config) override; 75 // Verify settings are valid for a capture or reprocessing. 76 bool isValidRequestSettings(const android::CameraMetadata& settings) override; 77 // Enqueue a request to receive data from the camera. 78 int enqueueRequest( 79 std::shared_ptr<default_camera_hal::CaptureRequest> request) override; 80 // Flush in flight buffers. 81 int flushBuffers() override; 82 83 // Async request processing helpers. 84 // Dequeue a request from the waiting queue. 85 // Blocks until a request is available. 86 std::shared_ptr<default_camera_hal::CaptureRequest> dequeueRequest(); 87 88 // Thread functions. Return true to loop, false to exit. 89 // Pass buffers for enqueued requests to the device. 90 bool enqueueRequestBuffers(); 91 // Retreive buffers from the device. 92 bool dequeueRequestBuffers(); 93 94 // V4L2 helper. 95 std::shared_ptr<V4L2Wrapper> device_; 96 std::unique_ptr<V4L2Wrapper::Connection> connection_; 97 std::unique_ptr<Metadata> metadata_; 98 std::mutex request_queue_lock_; 99 std::queue<std::shared_ptr<default_camera_hal::CaptureRequest>> 100 request_queue_; 101 std::mutex in_flight_lock_; 102 // Maps buffer index : request. 103 std::map<uint32_t, std::shared_ptr<default_camera_hal::CaptureRequest>> 104 in_flight_; 105 // Threads require holding an Android strong pointer. 106 android::sp<android::Thread> buffer_enqueuer_; 107 android::sp<android::Thread> buffer_dequeuer_; 108 std::condition_variable requests_available_; 109 std::condition_variable buffers_in_flight_; 110 111 int32_t max_input_streams_; 112 std::array<int, 3> max_output_streams_; // {raw, non-stalling, stalling}. 113 114 DISALLOW_COPY_AND_ASSIGN(V4L2Camera); 115 }; 116 117 } // namespace v4l2_camera_hal 118 119 #endif // V4L2_CAMERA_HAL_V4L2_CAMERA_H_ 120
