Android摄像头采撷Demo

定义MyCameraContext类，该类必须继承CameraListener，采集到数据时，将会触发该类内部定义的回调函数:postData。注意android2.3,和2.2在构造函数上是有区别的

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//MyCameraContext.h #ifndef MY_CAMERA_H#define  MY_CAMERA_H#include "jni.h"//#include "JNIHelp.h"#include "android_runtime/AndroidRuntime.h"#include <utils/Vector.h>#include <surfaceflinger/Surface.h>#include <camera/Camera.h>#include <binder/IMemory.h>#include <stdint.h>using namespace android;class MyCameraContext: public CameraListener{public:    MyCameraContext(const sp<Camera>& camera);    ~MyCameraContext() { ; }    //特殊事件通知回调，包括错误之类....目前在Demo中未使用    virtual void notify(int32_t msgType, int32_t ext1, int32_t ext2);    //采集数据回调....    virtual void postData(int32_t msgType, const sp<IMemory>& dataPtr);    //获取时间回调........目前在Demo中未使用    virtual void postDataTimestamp(nsecs_t timestamp, int32_t msgType, const sp<IMemory>& dataPtr);    void setCallbackMode();    void getcallbackfunc(void(*p)(void* lpdata,int len) ){mcallbackfunc=p; };    sp<Camera> getCamera() { return mCamera; }private:        void(*mcallbackfunc)(void* lpdata,int len) ;    void copyAndPost(const sp<IMemory>& dataPtr, int msgType);    sp<Camera>  mCamera;                // strong reference to native object   // Mutex       mLock;};sp<Camera> CreateCamera();sp<MyCameraContext> CreateCameraContext(sp<Camera>& spCamera);int setPreviewDisplaysurface(sp<Camera>& spCamera, sp<Surface>& surface);#endif//MyCameraContext.cpp #include "MyCamera.h"MyCameraContext::MyCameraContext(const sp<Camera>& camera){    mCamera = camera;}void MyCameraContext::notify(int32_t msgType, int32_t ext1, int32_t ext2){}void MyCameraContext::copyAndPost( const sp<IMemory>& dataPtr, int msgType){    jbyteArray obj = NULL;    if (dataPtr != NULL) {        ssize_t offset;        size_t size;        sp<IMemoryHeap> heap = dataPtr->getMemory(&offset, &size);        mcallbackfunc((void*)(heap->getBase()+offset),size);        uint8_t *heapBase = (uint8_t*)heap->base();        }}void MyCameraContext::postData(int32_t msgType, const sp<IMemory>& dataPtr){    copyAndPost(dataPtr, msgType);}void MyCameraContext::postDataTimestamp(nsecs_t timestamp, int32_t msgType, const sp<IMemory>& dataPtr){    postData(msgType, dataPtr);}void MyCameraContext::setCallbackMode(){    mCamera->setPreviewCallbackFlags(FRAME_CALLBACK_FLAG_CAMERA);}#ifdef ANDROID2_3  //android2.3sp<Camera> CreateCamera(){        int NumberOfCameras=Camera::getNumberOfCameras();        CameraInfo cameraInfo;        for (int i = 0; i < NumberOfCameras; i++) {                    status_t rc = Camera::getCameraInfo(i, &cameraInfo);                    if (rc != NO_ERROR) {                                        break;                     }                if(cameraInfo.facing==CAMERA_FACING_BACK) {                        sp<Camera> camera = Camera::connect(i);                        return camera;                }        }        return NULL;}#else //android 2.2sp<Camera> CreateCamera(){        sp<Camera> camera = Camera::connect();        if(camera->get())                return camera;        return NULL;}#endifsp<MyCameraContext> CreateCameraContext(sp<Camera>& spCamera){    sp<MyCameraContext> context = new MyCameraContext(spCamera);    spCamera->setListener(context);    return context;}int setPreviewDisplaysurface(sp<Camera>& spCamera, sp<Surface>& surface){        if (spCamera->setPreviewDisplay(surface) != NO_ERROR)                return -1;        return 1;}//测试demo:#include "MyCamera.h"void databackfunc(void *base,int size)；void databackfunc(void *base,int size){  //注意数据格式的处理  //spCamera->getParameters(); 获取各种采集参数包括格式   //数据处理}JNIEXPORT  jint Java_lpc_bairui_android_lpc_camera(JNIEnv* env, jclass clazz){        sp<Surface> sps;        sp<Camera> spCamera=CreateCamera();        if(spCamera.get()){                        spCameraContext=CreateCameraContext(spCamera);                if(spCameraContext.get()){                        /*并没有为sps赋值，所以它不指向任何Surface，所以将不会创建预览格式，仅仅获取数据                        setPreviewDisplaysurface函数在*/                        if( setPreviewDisplaysurface(spCamera,sps)==1){                                //String8  str("preview-size=240x320");                                //spCamera->setParameters(str);                                //spCamera->getParameters().string();                                spCameraContext->setCallbackMode();                                //设置处理采集到数据的回调函数                                spCameraContext->getcallbackfunc(databackfunc);                                //开始采集                                spCamera->startPreview();                                                                return 1;                        }                                        }        }        return 0;}

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