Android摄像头采集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
//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 //android2.3
sp<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 2.2
sp<Camera> CreateCamera()
{
sp<Camera> camera = Camera::connect();
if(camera->get())
return camera;
return NULL;
}
#endif
sp<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;
}