android Camera相機類

Camera相機類相關的幾個流程方法

Camera.open(cameraId) 打開相機

camera.setDisplayOrientation(0) 設置相機水平方向

mCamera.setPreviewDisplay(holder) 在SurfaceHolder上顯示畫面

mCamera.setPreviewCallback(callback) 設置回調，將Yuv數據傳遞到onPreviewFrame方法

previewRate mParams = mCamera.getParameters() 獲取相機相關參數

mCamera.stopPreview() 停止預覽

mCamera.release() 釋放相機

實現Camera.PreviewCallback介面獲取Yuv視頻流

@Override
public void onPreviewFrame(byte[] bytes, Camera camera) {
       //獲取實時的Yuv數據流
}

實現Camera.PictureCallback介面實現拍照

@Override
public void onPictureTaken(byte[] bytes, Camera camera) {
    try {
        FileOutputStream fileOutputStream=new FileOutputStream("/mnt/sdcard/DCIM/cameras/"+System.currentTimeMillis()+".png");
        fos.write(bytes);
        fos.close();
        //重新打開預覽    
        camera.stopPreview();
        camera.startPreview();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
}

尋找相機

private int findCamera(boolean isfront) {
    int cameraCount = 0;
    Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
    cameraCount = Camera.getNumberOfCameras();

    for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
        Camera.getCameraInfo(camIdx, cameraInfo);
        if (isfront) {
            // CAMERA_FACING_FRONT前置
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                return camIdx;
            }
        } else {
            // CAMERA_FACING_BACK後置
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
                return camIdx;
            }
        }

    }
    return -1;
}

Camera.Parameters相機參數類

Camera.Parameters parameters = camera.getParameters(); //獲取相機參數

List<Size> supportedPreviewSizes = parameters.getSupportedPreviewSizes(); //獲取攝像頭支持的各種解析度

parameters.setPictureFormat(PixelFormat.JPEG);//設置照片格式

parameters.setPreviewSize(witdh,height); //設置預覽尺寸

parameters.setPictureSize（witdh,height);

camera.setParameters(parameters);//提交相機參數

設置相機解析度

private void initCamera(Camera mCamera){
    if(mCamera != null){
        try{
            mParams = mCamera.getParameters();
            Size previewSize = CamParaUtil.getInstance().getPropPreviewSize(mParams.getSupportedPreviewSizes(),1.333f, 640);
            Log.d("log", String.valueOf(previewSize.width) + "-" + previewSize.height);
            pWidth = previewSize.width;
            pHeight = previewSize.height;
            mParams.setPreviewSize(pWidth, pHeight);

            List<String> focusModes = mParams.getSupportedFocusModes();
            if(focusModes.contains("continuous-video")){
                mParams.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
            }
            mCamera.setParameters(mParams);
            mCamera.startPreview();

            isPreviewing = true;
            mPreviwRate = previewRate;
        }catch (Exception ex){
            ex.printStackTrace();
        }

    }
}

public Size getPropPreviewSize(List<Size> list, float th, int minWidth){
    Collections.sort(list, sizeComparator);

    int i = 0;
    for(Size s:list){
        if((s.width >= minWidth) && equalRate(s, th)){
            break;
        }
        i++;
    }
    if(i == list.size()){
    }
    return list.get(i);
}

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