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 #ifndef ANDROID_HARDWARE_AUTOMOTIVE_EVS_V1_0_EVSV4LCAMERA_H
18 #define ANDROID_HARDWARE_AUTOMOTIVE_EVS_V1_0_EVSV4LCAMERA_H
19 
20 #include <android/hardware/automotive/evs/1.0/types.h>
21 #include <android/hardware/automotive/evs/1.0/IEvsCamera.h>
22 #include <ui/GraphicBuffer.h>
23 
24 #include <thread>
25 #include <functional>
26 
27 #include "VideoCapture.h"
28 
29 
30 namespace android {
31 namespace hardware {
32 namespace automotive {
33 namespace evs {
34 namespace V1_0 {
35 namespace implementation {
36 
37 
38 // From EvsEnumerator.h
39 class EvsEnumerator;
40 
41 
42 class EvsV4lCamera : public IEvsCamera {
43 public:
44     // Methods from ::android::hardware::automotive::evs::V1_0::IEvsCamera follow.
45     Return<void> getCameraInfo(getCameraInfo_cb _hidl_cb)  override;
46     Return <EvsResult> setMaxFramesInFlight(uint32_t bufferCount) override;
47     Return <EvsResult> startVideoStream(const ::android::sp<IEvsCameraStream>& stream) override;
48     Return<void> doneWithFrame(const BufferDesc& buffer) override;
49     Return<void> stopVideoStream() override;
50     Return <int32_t> getExtendedInfo(uint32_t opaqueIdentifier) override;
51     Return <EvsResult> setExtendedInfo(uint32_t opaqueIdentifier, int32_t opaqueValue) override;
52 
53     // Implementation details
54     EvsV4lCamera(const char *deviceName);
55     virtual ~EvsV4lCamera() override;
56     void shutdown();
57 
getDesc()58     const CameraDesc& getDesc() { return mDescription; };
59 
60 private:
61     // These three functions are expected to be called while mAccessLock is held
62     bool setAvailableFrames_Locked(unsigned bufferCount);
63     unsigned increaseAvailableFrames_Locked(unsigned numToAdd);
64     unsigned decreaseAvailableFrames_Locked(unsigned numToRemove);
65 
66     void forwardFrame(imageBuffer* tgt, void* data);
67 
68     sp <IEvsCameraStream> mStream = nullptr;  // The callback used to deliver each frame
69 
70     VideoCapture          mVideo;   // Interface to the v4l device
71 
72     CameraDesc mDescription = {};   // The properties of this camera
73     uint32_t mFormat = 0;           // Values from android_pixel_format_t
74     uint32_t mUsage  = 0;           // Values from from Gralloc.h
75     uint32_t mStride = 0;           // Pixels per row (may be greater than image width)
76 
77     struct BufferRecord {
78         buffer_handle_t handle;
79         bool inUse;
80 
BufferRecordBufferRecord81         explicit BufferRecord(buffer_handle_t h) : handle(h), inUse(false) {};
82     };
83 
84     std::vector <BufferRecord> mBuffers;    // Graphics buffers to transfer images
85     unsigned mFramesAllowed;                // How many buffers are we currently using
86     unsigned mFramesInUse;                  // How many buffers are currently outstanding
87 
88     // Which format specific function we need to use to move camera imagery into our output buffers
89     void(*mFillBufferFromVideo)(const BufferDesc& tgtBuff, uint8_t* tgt,
90                                 void* imgData, unsigned imgStride);
91 
92     // Synchronization necessary to deconflict the capture thread from the main service thread
93     // Note that the service interface remains single threaded (ie: not reentrant)
94     std::mutex mAccessLock;
95 };
96 
97 } // namespace implementation
98 } // namespace V1_0
99 } // namespace evs
100 } // namespace automotive
101 } // namespace hardware
102 } // namespace android
103 
104 #endif  // ANDROID_HARDWARE_AUTOMOTIVE_EVS_V1_0_EVSV4LCAMERA_H
105