** How to create a camera2<\/a>**<\/p>\n \u00a0<\/p>\n How to create a camera 2.<\/strong><\/p>\n Step1:To enumerate, query, and open available camera devices, obtain a CameraManager instance.<\/p>\n \u5f9esystem\u53d6\u5f97cameraManager\u3002<\/p>\n Initialize CameraDevice:<\/strong><\/p>\n Step2:Individual CameraDevices provide a set of static property information that describes the hardware device and the available settings and output parameters for the device.<\/p>\n \u6839\u64dasystem \u53d6\u5f97 CameraCharacteristics \u53bb\u6e96\u5099\u958b\u555fCameraDevice<\/p>\n CameraDevice.StateListener:<\/strong><\/p>\n A listener for notifications about the state of a camera device<\/p>\n \u7e3d\u662f\u8981\u53bb\u76e3\u807ddevice\u662f\u5426\u958b\u555f\uff0c\u95dc\u9589\uff0c\u786c\u9ad4\u932f\u8aa4\u7b49\u7b49<\/p>\n CameraDevice:<\/strong><\/p>\n The CameraDevice class is a representation of a single camera connected to an Android device, allowing for fine-grain control of image capture and post-processing at high frame rates.<\/p>\n Device is modeled as a pipeline<\/p>\n \u91cd\u8981\u7684\u4e3b\u63a7\u7aef\uff0c\u8ca0\u8cac\u63a5\u6536\u6240\u6709callback \u548c\u5c0ddevice\u7684\u63a7\u5236<\/p>\n \u662f\u4e00\u500bpipline\u7684\u6a21\u7d44\u3002\u7c21\u55ae\u4f86\u8aaa\u7684\u6d41\u7a0b<\/p>\n Input : CaptureRequest for a single Frame<\/p>\n Output: CaptureResult Metadata packet + output image buffers for the request. These buffers can go to one or multiple output targets.<\/p>\n Start preview :<\/strong><\/p>\n Step3:To capture or stream images from a camera device, the application must first create a camera capture session with a set of output Surfaces for use with the camera device.<\/p>\n \u958b\u555f\u9810\u89bd\u756b\u9762\uff0c\u57fa\u672c\u4e0a\u53ef\u4ee5\u540c\u6642\u767c\u5230\u597d\u5e7e\u500bsurface<\/p>\n \u9019\u88e1\u4ee5\u55ae\u4e00surface\u70ba\u4e3b\uff0c\u9019\u88e1\u8981\u8a18\u5f97\u958b\u555fcapturesession\u662f\u5fc5\u9808\u5305\u542b\u672a\u4f86\u6700\u5927\u5b50\u96c6\u9700\u8981\u7528\u5230\u7684surface<\/p>\n CaptureRequest.Builder:<\/strong><\/p>\n \u2013 A builder for capture requests.<\/p>\n \u2013 To obtain a builder instance, use the createCaptureRequest(int) method, which initializes the request fields to one of the templates defined in CameraDevice.<\/p>\n \u6240\u6709\u7684request\u90fd\u5fc5\u9808\u7d93\u904e\u6307\u5b9a\u63d0\u4f9b\u7684builder\u7684\u63d0\u4f9b\uff0c\u9019\u5728\u4e0d\u5c11android\u7684\u8a2d\u8a08\u90fd\u662f\u9019\u6a23\u641e<\/p>\n \u50cf\u662fnotification\u3002<\/p>\n \u901a\u5e38\u8981\u5beb\u5165captureRequest\u7684field \u8a2d\u5b9a\u548c\u8f38\u51fa\u7684target surface.<\/p>\n CaptureRequest:<\/strong><\/p>\n \u2013 An immutable package of settings and outputs needed to capture a single image from the camera device.<\/p>\n \u2013 Contains the configuration for the capture hardware (sensor, lens, flash), the processing pipeline, the control algorithms, and the output buffers. Also contains the list of target Surfaces to send image data to for this capture.<\/p>\n \u2013 CaptureRequests can be created by using a CaptureRequest.Builder instance, obtained by calling createCaptureRequest(int)<\/p>\n \u61f6\u5f97\u89e3\u91cb\u4e86\uff0c\u6839\u64da\u4e0a\u9801\uff0c\u505a\u51fa\u4f86\u7684request\u901a\u5e38\u6703\u6709\u5927\u91cf\u7684\u8cc7\u8a0a\uff0c\u4e00\u822c\u4f86\u8aaa1 request \u00a0\u5c0d\u61c91 image data<\/p>\n \u9019\u4e5f\u662fcamera2 \u7684\u91cd\u8981\u7279\u8272\uff0c\u5728request \u4e2d\u53ef\u4ee5\u653e\u5165\u5404\u7a2e\u8a2d\u5b9a\u548c\u8f38\u51fasurface\uff0c\u6240\u4ee5\u53ef\u4ee5\u540c\u6642\u6709\u5f88\u591a\u7a2e\u8b8a\u5316\u5728\u5f88\u77ed\u7684\u6642\u9593(fps)<\/p>\n CameraCaptureSession.StateListener:<\/strong><\/p>\n A listener for tracking the state of a camera capture session.<\/p>\n \u9664\u4e86\u4e4b\u524d\u7684cameradevice\u76e3\u63a7\uff0c\u4e4b\u5916\u9084\u8981\u76e3\u63a7capturesession\u72c0\u6cc1<\/p>\n \u524d\u8ff0\u6709\u63d0\u904e\uff0c\u7576\u958b\u555fcameraDevice\u9084\u662f\u8981\u958b\u555f\u5c08\u9580\u7684session\u53bb\u57f7\u884c<\/p>\n captureSession\u7684\u8a73\u7d30\u5167\u5bb9\u53ef\u4ee5\u53c3\u8003\u4e0b\u4e00\u9801<\/p>\n CameraCaptureSession:<\/strong><\/p>\n \u2013 A configured capture session for a CameraDevice, used for capturing images from the camera.<\/p>\n \u2013 A CameraCaptureSession is created by providing a set of target output surfaces to createCaptureSession. Once created, the session is active until a new session is created by the camera device, or the camera device is closed.<\/p>\n CaptureSession\u7684\u5e7e\u500bapi\u5f88\u660e\u986f\u5c31\u662f\u4f86\u89e3\u6c7a zero shutter lag\uff0c\u81ea\u5df1\u611f\u53d7\u611f\u53d7<\/p>\n \u4e0d\u5f97\u4e0d\u8aaa\u90a3\u500bburst\u6839\u672c\u5c31\u662fburst\uff0c\u81ea\u5df1\u5beb\u904e\u5e7e\u6b21\u5c31\u77e5\u9053\u5566\uff0c\u4e0d\u904e\u8981\u771f\u7684\u5feb\u7684\u8a71\u76ee\u524d\u53ea\u6709nexus 9 \u548c 6\u3002<\/p>\n Take picture1:<\/strong><\/p>\n Step4: Capture of JPEG images or RAW buffers for Dng Creator can be done with ImageReader with the {android.graphics.ImageFormat#JPEG} and {android.graphics.ImageFormat#RAW_SENSOR} formats.<\/p>\n raw buffer \u00a0\u662fcamera2 \u624d\u652f\u63f4\uff5e\uff5e<\/p>\n \u627f\u4e0a takePicture2<\/strong><\/p>\n Step5:Use ImageReader to get output data<\/p>\n ImageReader:<\/strong><\/p>\n The ImageReader class allows direct application access to image data rendered into a Surface<\/p>\n \u70ba\u4e00\u7a2e\u66ab\u5b58\u7684 image data buffer consumer. \u6bd4\u8f03\u7279\u5225\u7684\u662f\u6709size\u53ef\u4ee5\u8a2d\u5b9a\uff0capi19\u524d\u5e7e\u4e4e\u6c92\u6709\u3002<\/p>\n Take picture3<\/strong><\/p>\n Step6:Set output data parameters.<\/p>\n \u6b64\u968e\u6bb5\u540c\u6642\u8a2d\u5b9a image reader listener\uff0c\u7528\u4f86\u63a5\u6536device\u767c\u51fa\u7684\u8cc7\u6599\u3002<\/p>\n ImageReader.OnImageAvailableListener<\/strong><\/p>\n Callback interface for being notified that a new image is available.<\/p>\n Take picture4<\/strong><\/p>\n Step7:Set output data parameters. And start camera capture picture thread.\u00a0<\/p>\n takePicture5<\/strong><\/p>\n Step8:Restart preview thread after capture complete.<\/p>\n \u9019\u88e1\u662f\u6709\u9806\u5e8f\u7684\uff0c\u518dcapturesession listener \u7684 capture complete \u5f8c\u91cd\u8d77startpreview()<\/p>\n \u5148\u8aaa\u9019\u500bstartpreview()\u4e0d\u662fcamera1\u7684api \uff0c\u800c\u662f\u4e4b\u524d\u6211\u5011\u81ea\u5df1\u5beb\u7684 startpreview()<\/p>\n \u4ee5\u767c\u751f\u6642\u9593\u4f86\u6392\u5e8f\u662f\u53f3\u908a\u5148 \u5de6\u908a\u5f8c<\/p>\n then<\/p>\n \u4ee5\u4e0a\u662fCamera2\u7684takePicture\u7c21\u6613\u5be6\u4f5c\u904e\u7a0b\uff0c\u6700\u91cd\u8981\u7684\u9084\u662f\u627e\u5230\u4e00\u53f0\u53ef\u4ee5\u8dd1hal3\u7684\u6a5f\u5668<\/p>\n \u4e0d\u7136\u5f88\u591a\u529f\u80fd\u90fd\u662f\u95dc\u6389\u7684\uff0c\u7d50\u679c\u5c31\u6703\u50cf\u662f\u53ea\u662f\u63db\u500b\u5beb\u6cd5\u5bebcamera1<\/p>\n \u5b8c\u6574\u7a0b\u5f0f\u78bc<\/p>\n https:\/\/github.com\/googlesamples\/android-Camera2Basic<\/a><\/p>\n google i\/o \u4ecb\u7d39<\/p>\npage2:<\/h4>\n
\/\/ To get a list of available sizes of camera preview, we retrieve an instance of\n\/\/ StreamConfigurationMap from CameraCharacteristics\nCameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);\nStreamConfigurationMap map = characteristics\n .get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP);\n (Camera.Size) mPreviewSize = map.getOutputSizes(SurfaceTexture.class)[0];\n (SurfaceTexture) mTextureView.setAspectRatio(mPreviewSize.getWidth(), \n\/\/ We are opening the camera with a listener. When it is ready, onOpened of\n\/\/ (CameraDevice.StateListener)mStateListener is called.\nmanager.openCamera(cameraId, mStateListener, null);<\/code><\/pre>\npage3:<\/h4>\n
CameraCharacteristics characteristics = manager.getCameraCharacteristics(cameraId);\nmanager.openCamera(cameraId, mStateListener, null);<\/code><\/pre>\npage4:<\/h4>\n
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\/\/ We configure the size of default buffer to be the size of camera preview we want.<\/span>\ntexture.setDefaultBufferSize(mPreviewSize.getWidth(), mPreviewSize.getHeight());\n\/\/ This is the output Surface we need to start preview.<\/span>\nSurface<\/span> surface<\/span> =<\/span> new<\/span> Surface<\/span>(texture);\n\/\/ We set up a CaptureRequest.Builder with the output Surface.<\/span>\nmPreviewBuilder = mCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW);\nmPreviewBuilder.addTarget(surface);\n\/\/ Here, we create a CameraCaptureSession for camera preview.<\/span>\nmCameraDevice.createCaptureSession(Arrays.asList(surface),\n new<\/span> CameraCaptureSession<\/span>.StateListener(){.....}<\/code><\/pre>\npage7:<\/h4>\n
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public<\/span> void<\/span> onConfigured<\/span>(CameraCaptureSession cameraCaptureSession)<\/span> {\n \/\/ When the session is ready, we start displaying the preview.<\/span>\n mPreviewSession = cameraCaptureSession;\n \/\/ In this sample, we just let the camera device pick the automatic settings.<\/span>\n\t\t mPreviewBuilder.set(CaptureRequest.CONTROL_MODE\n\t\t\t\t, CameraMetadata.CONTROL_MODE_AUTO);\n HandlerThread<\/span> thread<\/span> =<\/span> new<\/span> HandlerThread<\/span>("CameraPreview"<\/span>);\n thread.start();\n Handler<\/span> backgroundHandler<\/span> =<\/span> new<\/span> Handler<\/span>(thread.getLooper());\n \/\/ Finally, we start displaying the camera preview.<\/span>\n mPreviewSession.setRepeatingRequest(mPreviewBuilder.build(), null<\/span>, backgroundHandler);\n }<\/code><\/pre>\npage10:<\/h4>\n
capture(CaptureRequest request, CameraCaptureSession.CaptureListener listener, Handler handler)\nSubmit a request for an image to be captured by the camera device.\n\ncaptureBurst(List requests, CameraCaptureSession.CaptureListener listener, Handler handler)\nSubmit a list of requests to be captured in sequence as a burst.\n\nsetRepeatingBurst(List requests, CameraCaptureSession.CaptureListener listener, Handler handler)\nRequest endlessly repeating capture of a sequence of images by this capture session.\n\nsetRepeatingRequest(CaptureRequest request, CameraCaptureSession.CaptureListener listener, Handler handler)\nRequest endlessly repeating capture of images by this capture session.<\/code><\/pre>\npage11:<\/h4>\n
CameraManager<\/span> manager<\/span> =<\/span>\n (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);\n\/\/ Pick the best JPEG size that can be captured with this CameraDevice.<\/span>\nCameraCharacteristics<\/span> characteristics<\/span> =<\/span>\nmanager.getCameraCharacteristics(mCameraDevice.getId());\nSize<\/span>[] jpegSizes<\/span> =<\/span> null<\/span>;\nif<\/span> (characteristics != null<\/span>) {\n jpegSizes = characteristics.get(CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP) .getOutputSizes(ImageFormat.JPEG);\n }\n int<\/span> width<\/span> =<\/span> 640<\/span>; int<\/span> height<\/span> =<\/span> 480<\/span>;\n if<\/span> (jpegSizes != null<\/span> && 0<\/span> < jpegSizes.length) {\n width = jpegSizes[0<\/span>].getWidth();\n height = jpegSizes[0<\/span>].getHeight();\n }\n\n\/\/ This is the CaptureRequest.Builder that we use to take a picture.<\/span>\nfinal<\/span> CaptureRequest.Builder<\/span> captureBuilder<\/span> =<\/span>\nmCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);\ncaptureBuilder.addTarget(reader.getSurface());\n\/\/ In this sample, we just let the camera device pick the automatic settings. captureBuilder.set(CaptureRequest.CONTROL_MODE,CameraMetadata.CONTROL_MODE_AUTO);<\/span><\/code><\/pre>\npage12:<\/h4>\n
\/\/ We use an ImageReader to get a JPEG from CameraDevice.<\/span>\n\/\/ Here, we create a new ImageReader and prepare its Surface as an output from camera.<\/span>\nImageReader<\/span> reader<\/span> =<\/span> ImageReader.newInstance(width, height, ImageFormat.JPEG, 1<\/span>);\nList<\/span> outputSurfaces<\/span> =<\/span> new<\/span> ArrayList<\/span>(2<\/span>);\noutputSurfaces.add(reader.getSurface());\noutputSurfaces.add(new<\/span> Surface<\/span>(mTextureView.getSurfaceTexture()));\n\n\/\/ This is the CaptureRequest.Builder that we use to take a picture.<\/span>\nfinal<\/span> CaptureRequest.Builder<\/span> captureBuilder<\/span> =<\/span>\nmCameraDevice.createCaptureRequest(CameraDevice.TEMPLATE_STILL_CAPTURE);\ncaptureBuilder.addTarget(reader.getSurface());\n\/\/ In this sample, we just let the camera device pick the automatic settings. captureBuilder.set(CaptureRequest.CONTROL_MODE,CameraMetadata.CONTROL_MODE_AUTO);<\/span><\/code><\/pre>\npage13:<\/h4>\n
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\/\/ In this sample, we just let the camera device pick the automatic settings.<\/span>\ncapturebuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);\n\/\/ Orientation<\/span>\nint<\/span> rotation<\/span> =<\/span> activity.getWindowManager().getDefaultDisplay().getRotation();\ncaptureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));\n\/\/ Output file<\/span>\nfinal<\/span> File<\/span> file<\/span> =<\/span> new<\/span> File<\/span>(activity.getExternalFilesDir(null<\/span>), "pic.jpg"<\/span>);\n\/\/ This listener is called when a image is ready in ImageReader<\/span>\nImageReader.OnImageAvailableListener<\/span> readerListener<\/span> =<\/span>\nnew<\/span> ImageReader<\/span>.OnImageAvailableListener() {\u2026.}<\/code><\/pre>\npage15:<\/h4>\n
onImageAvailable(ImageReader reader) {\u00a0\nimage = reader.acquireLatestImage();\nByteBuffer<\/span> buffer<\/span> =<\/span> image.getPlanes()[0<\/span>].getBuffer();\nbyte<\/span>[] bytes<\/span> =<\/span> new<\/span> byte<\/span>[buffer.capacity()];\nbuffer.get(bytes);\nsave(bytes);\n\u2026..\/\/Use output stream to write out to file.<\/span>\n\u2026\u2026\nImage.close();<\/code><\/pre>\npage16:<\/h4>\n
\/\/ In this sample, we just let the camera device pick the automatic settings.<\/span>\ncapturebuilder.set(CaptureRequest.CONTROL_MODE, CameraMetadata.CONTROL_MODE_AUTO);\n\/\/ Orientation<\/span>\nint<\/span> rotation<\/span> =<\/span> activity.getWindowManager().getDefaultDisplay().getRotation();\ncaptureBuilder.set(CaptureRequest.JPEG_ORIENTATION, ORIENTATIONS.get(rotation));\n\/\/ Output file<\/span>\nfinal<\/span> File<\/span> file<\/span> =<\/span> new<\/span> File<\/span>(activity.getExternalFilesDir(null<\/span>), "pic.jpg"<\/span>);\n\/\/ This listener is called when a image is ready in ImageReader<\/span>\n ImageReader.OnImageAvailableListener<\/span> readerListener<\/span> =<\/span>\n new<\/span> ImageReader<\/span>.OnImageAvailableListener() {\u2026.}\n\/\/ We create a Handler since we want to handle the result JPEG in a background thread<\/span>\nHandlerThread<\/span> thread<\/span> =<\/span> new<\/span> HandlerThread<\/span>("CameraPicture"<\/span>);\nthread.start();\nfinal<\/span> Handler<\/span> backgroundHandler<\/span> =<\/span> new<\/span> Handler<\/span>(thread.getLooper());\nreader.setOnImageAvailableListener(readerListener, backgroundHandler);<\/code><\/pre>\npage17:<\/h4>\n
\/\/ Finally, we can start a new CameraCaptureSession to take a picture. mCameraDevice.createCaptureSession(outputSurfaces,<\/span>\nnew<\/span> CameraCaptureSession<\/span>.StateListener() {\npublic<\/span> void<\/span> onConfigured<\/span>(CameraCaptureSession session)<\/span> {\n\ttry<\/span> {\n\t\tsession.capture(captureBuilder.build(), captureListener,\n backgroundHandler);\n\t} catch<\/span> (CameraAccessException e) {\n\t\te.printStackTrace();\n\t}\n }\n}, backgroundHandler );<\/code><\/pre>\n\/\/ This listener is called when the capture is completed.<\/span>\n\/\/ Note that the JPEG data is not available in this listener, but in the<\/span>\n \/\/ ImageReader.OnImageAvailableListener we created above.<\/span>\n final<\/span> CameraCaptureSession.CaptureListener<\/span> captureListener<\/span> =<\/span>\n\tnew<\/span> CameraCaptureSession<\/span>.CaptureListener() {\n\tpublic<\/span> void<\/span> onCaptureCompleted<\/span>(CameraCaptureSession session,\n\tCaptureRequest request, TotalCaptureResult result)<\/span> {\n \/\/ We restart the preview when the capture is completed<\/span>\n startPreview();\n\t\t\t}\n\t\t};<\/code><\/pre>\n