CameraPreview.java 文件源码

@Override
// Decode the image data and rotate it to the proper orientation.
// then run the callback, if any, on the image to do post processing
protected Boolean doInBackground(Object... params) {
    byte[] data = (byte[]) params[0];
    Camera camera = (Camera) params[1];
    Camera.Parameters parameters = camera.getParameters();
    int format = parameters.getPreviewFormat();
    //YUV formats require more conversion
    if (format == ImageFormat.NV21 || format == ImageFormat.YUY2 || format == ImageFormat.NV16) {
        int w = parameters.getPreviewSize().width;
        int h = parameters.getPreviewSize().height;
        // Get the YuV image
        YuvImage yuv_image = new YuvImage(data, format, w, h, null);
        // Convert YuV to Jpeg
        Rect rect = new Rect(0, 0, w, h);
        ByteArrayOutputStream output_stream = new ByteArrayOutputStream();
        yuv_image.compressToJpeg(rect, 100, output_stream);
        byte[] imageBytes = output_stream.toByteArray();
        Bitmap bitmap = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);

        Matrix transform = new Matrix();
        if (mCameraFacing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
            transform.preScale(-1, 1);
        }
        transform.postRotate(mCameraRotation);
        bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), transform, true);

        if (mCapturedCapturedImageCallbackAsync != null) {
            mCapturedCapturedImageCallbackAsync.execute(bitmap);
        }
    }
    return null;
}