android 录制视频（环信）

public class CameraHelper implements PreviewCallback {
private static final String TAG = "CameraHelper";

static final int mwidth = 640;
static final int mheight = 480;

private Camera mCamera;
private int camera_count;

private Parameters mParameters;

private byte[] yuv_frame;

private byte[] yuv_Rotate90;

//    private byte[] yuv_Rotate90lr;

private SurfaceHolder localSurfaceHolder;

private boolean start_flag;

private EMVideoCallHelper callHelper;

private CameraInfo cameraInfo;

public CameraHelper(EMVideoCallHelper callHelper, SurfaceHolder localSurfaceHolder) {
this.callHelper = callHelper;
this.localSurfaceHolder = localSurfaceHolder;
}

/**
* 开启相机拍摄
*/
public void startCapture(){
try {
cameraInfo = new CameraInfo();
if (mCamera == null) {
// mCamera = Camera.open();
camera_count = Camera.getNumberOfCameras();
Log.e(TAG, "camera count:" + camera_count);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
for (int i = 0; i < camera_count; i++) {
CameraInfo info = new CameraInfo();
Camera.getCameraInfo(i, info);
// find front camera
if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
Log.e(TAG, "to open front camera");
mCamera = Camera.open(i);
Camera.getCameraInfo(i, cameraInfo);
}
}
}
if (mCamera == null) {
Log.e(TAG, "AAAAA OPEN camera");
mCamera = Camera.open();
Camera.getCameraInfo(0, cameraInfo);
}

}

mCamera.stopPreview();
mParameters = mCamera.getParameters();
if (isScreenOriatationPortrait()) {
if(cameraInfo.orientation == 270)
mCamera.setDisplayOrientation(90);
if(cameraInfo.orientation == 90)
mCamera.setDisplayOrientation(270);
}else{
if(cameraInfo.orientation == 90)
mCamera.setDisplayOrientation(180);
}

mParameters.setPreviewSize(mwidth, mheight);
mParameters.setPreviewFrameRate(15);
mCamera.setParameters(mParameters);
int mformat = mParameters.getPreviewFormat();
int bitsperpixel = ImageFormat.getBitsPerPixel(mformat);
Log.e(TAG, "pzy bitsperpixel: " + bitsperpixel);
yuv_frame = new byte[mwidth * mheight * bitsperpixel / 8];
yuv_Rotate90 = new byte[mwidth * mheight * bitsperpixel / 8];
//            yuv_Rotate90lr = new byte[mwidth * mheight * bitsperpixel / 8];
mCamera.addCallbackBuffer(yuv_frame);
// mCamera.setPreviewDisplay(holder);
mCamera.setPreviewDisplay(localSurfaceHolder);
mCamera.setPreviewCallbackWithBuffer(this);

EMVideoCallHelper.getInstance().setResolution(mwidth, mheight);

mCamera.startPreview();
Log.d(TAG, "camera start preview");
} catch (Exception e) {
e.printStackTrace();
if(mCamera != null)
mCamera.release();
}
}

@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (start_flag == true) {
// 根据屏幕方向写入及传输数据
if (isScreenOriatationPortrait()) {
if(cameraInfo.orientation == 90)
YUV420spRotate90(yuv_Rotate90,yuv_frame,  mwidth,mheight);
else if(cameraInfo.orientation == 270)
YUV420spRotate270(yuv_Rotate90,yuv_frame,  mwidth,mheight);
callHelper.processPreviewData(mheight, mwidth, yuv_Rotate90);
} else {
if(cameraInfo.orientation == 90)
{
YUV420spRotate180(yuv_Rotate90,yuv_frame,mwidth,mheight);
YUV42left2right(yuv_frame,yuv_Rotate90,mwidth,mheight);
callHelper.processPreviewData(mheight, mwidth, yuv_frame);
}
else
{
YUV42left2right(yuv_Rotate90,yuv_frame,mwidth,mheight);
callHelper.processPreviewData(mheight, mwidth, yuv_Rotate90);
}

}
}
camera.addCallbackBuffer(yuv_frame);
}

/**
* 停止拍摄
*/
public void stopCapture() {
start_flag = false;
if (mCamera != null) {
mCamera.setPreviewCallback(null);
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
}

/**
* 获取是否已开启视频数据传输
*
* @return
*/
public boolean isStarted() {
return start_flag;
}

/**
* 设置是否传输视频数据
*
* @param start
*/
public void setStartFlag(boolean start) {
this.start_flag = start;
}

void YUV420spRotate90(byte[]  dst, byte[] src, int srcWidth, int srcHeight) {
int nWidth = 0, nHeight = 0;
int wh = 0;
int uvHeight = 0;
if(srcWidth != nWidth || srcHeight != nHeight) {
nWidth = srcWidth;
nHeight = srcHeight;
wh = srcWidth * srcHeight;
uvHeight = srcHeight >> 1;//uvHeight = height / 2
}
//旋转Y
int k = 0;
for(int i = 0; i < srcWidth; i++) {
int nPos = 0;
for(int j = 0; j < srcHeight; j++) {
dst[k] = src[nPos + i];
k++;
nPos += srcWidth;
}
}

for(int i = 0; i < srcWidth; i+=2){
int nPos = wh;
for(int j = 0; j < uvHeight; j++) {
dst[k] = src[nPos + i];
dst[k + 1] = src[nPos + i + 1];
k += 2;
nPos += srcWidth;
}
}
return;
}

void YUV420spRotate180(byte[]  dst, byte[] src, int srcWidth, int srcHeight) {
int nWidth = 0, nHeight = 0;
int wh = 0;
int uvsize = 0;
int uvHeight = 0;
if(srcWidth != nWidth || srcHeight != nHeight)  {
nWidth = srcWidth;
nHeight = srcHeight;
wh = srcWidth * srcHeight;
uvHeight = srcHeight >> 1;//uvHeight = height / 2
}
uvsize = wh>>1;
for(int i = 0;i<wh;i++){
dst[wh-1-i]=src[i];
}
for(int i = 0;i<uvsize;i+=2){
dst[wh+uvsize-2-i]= src[wh+i];
dst[wh+uvsize-1-i]= src[wh+i+1];
}
return;
}

void YUV420spRotate270(byte[]  dst, byte[] src, int srcWidth, int srcHeight) {
int nWidth = 0, nHeight = 0;
int wh = 0;
int uvHeight = 0;
if(srcWidth != nWidth || srcHeight != nHeight){
nWidth = srcWidth;
nHeight = srcHeight;
wh = srcWidth * srcHeight;
uvHeight = srcHeight >> 1;//uvHeight = height / 2
}

int k = 0;
for(int i = 0; i < srcWidth; i++){
int nPos = srcWidth - 1;
for(int j = 0; j < srcHeight; j++)
{
dst[k] = src[nPos - i];
k++;
nPos += srcWidth;
}
}

for(int i = 0; i < srcWidth; i+=2){
int nPos = wh + srcWidth - 1;
for(int j = 0; j < uvHeight; j++) {
dst[k] = src[nPos - i - 1];
dst[k + 1] = src[nPos - i];
k += 2;
nPos += srcWidth;
}
}
return;
}

void YUV42left2right(byte[] dst, byte[] src, int srcWidth, int srcHeight) {
// int nWidth = 0, nHeight = 0;
int wh = 0;
int uvHeight = 0;
// if(srcWidth != nWidth || srcHeight != nHeight)
{
// nWidth = srcWidth;
// nHeight = srcHeight;
wh = srcWidth * srcHeight;
uvHeight = srcHeight >> 1;// uvHeight = height / 2
}

// 转换Y
int k = 0;
int nPos = 0;
for (int i = 0; i < srcHeight; i++) {
nPos += srcWidth;
for (int j = 0; j < srcWidth; j++) {
dst[k] = src[nPos - j - 1];
k++;
}

}
nPos = wh + srcWidth - 1;
for (int i = 0; i < uvHeight; i++) {
for (int j = 0; j < srcWidth; j += 2) {
dst[k] = src[nPos - j - 1];
dst[k + 1] = src[nPos - j];
k += 2;

}
nPos += srcWidth;
}
return;
}

boolean isScreenOriatationPortrait() {
return DemoApplication.applicationContext.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT;
}
}