Rotate an YUV byte array on Android

Question

I\'m looking to rotate a YUV frame preview recieved from a Preview Callblack, so far I\'ve founded this post which cointains an algorithm to rotate the frame preview but is

Answer 1

The following method can rotate a YUV420 byte array by 90 degree.

private byte[] rotateYUV420Degree90(byte[] data, int imageWidth, int imageHeight) 
{
    byte [] yuv = new byte[imageWidth*imageHeight*3/2];
    // Rotate the Y luma
    int i = 0;
    for(int x = 0;x < imageWidth;x++)
    {
        for(int y = imageHeight-1;y >= 0;y--)                               
        {
            yuv[i] = data[y*imageWidth+x];
            i++;
        }
    }
    // Rotate the U and V color components 
    i = imageWidth*imageHeight*3/2-1;
    for(int x = imageWidth-1;x > 0;x=x-2)
    {
        for(int y = 0;y < imageHeight/2;y++)                                
        {
            yuv[i] = data[(imageWidth*imageHeight)+(y*imageWidth)+x];
            i--;
            yuv[i] = data[(imageWidth*imageHeight)+(y*imageWidth)+(x-1)];
            i--;
        }
    }
    return yuv;
}

(Note that this might only work if the width and height is a factor of 4)

Answer 2

Here's how I did it

This block of code is setup elsewhere

    Camera.Size size
    Rect rectangle = new Rect();
    rectangle.bottom = size.height;
    rectangle.top = 0;
    rectangle.left = 0;
    rectangle.right = size.width;

This is the method that does the work

    private Bitmap rotateBitmap(YuvImage yuvImage, int orientation, Rect rectangle)
    {
    ByteArrayOutputStream os = new ByteArrayOutputStream();
    yuvImage.compressToJpeg(rectangle, 100, os);

    Matrix matrix = new Matrix();
    matrix.postRotate(orientation);
    byte[] bytes = os.toByteArray();
    Bitmap bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
    return Bitmap.createBitmap(bitmap, 0 , 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
    }

compress the YUVImage into a JPEG so that bitmap can handle it. Rotate the bitmap and then export it. To get it back to a JPEG which is how I wanted it I used this line

image.compress(Bitmap.CompressFormat.JPEG, 50, outputStream);

Answer 3

Here are the options to turn a different corner (90, 180, 270):

public static byte[] rotateYUV420Degree90(byte[] data, int imageWidth, int imageHeight) {
    byte[] yuv = new byte[imageWidth * imageHeight * 3 / 2];
    // Rotate the Y luma
    int i = 0;
    for (int x = 0; x < imageWidth; x++) {
        for (int y = imageHeight - 1; y >= 0; y--) {
            yuv[i] = data[y * imageWidth + x];
            i++;
        }
    }
    // Rotate the U and V color components
    i = imageWidth * imageHeight * 3 / 2 - 1;
    for (int x = imageWidth - 1; x > 0; x = x - 2) {
        for (int y = 0; y < imageHeight / 2; y++) {
            yuv[i] = data[(imageWidth * imageHeight) + (y * imageWidth) + x];
            i--;
            yuv[i] = data[(imageWidth * imageHeight) + (y * imageWidth)
                    + (x - 1)];
            i--;
        }
    }
    return yuv;
}

private static byte[] rotateYUV420Degree180(byte[] data, int imageWidth, int imageHeight) {
    byte[] yuv = new byte[imageWidth * imageHeight * 3 / 2];
    int i = 0;
    int count = 0;
    for (i = imageWidth * imageHeight - 1; i >= 0; i--) {
        yuv[count] = data[i];
        count++;
    }
    i = imageWidth * imageHeight * 3 / 2 - 1;
    for (i = imageWidth * imageHeight * 3 / 2 - 1; i >= imageWidth
            * imageHeight; i -= 2) {
        yuv[count++] = data[i - 1];
        yuv[count++] = data[i];
    }
    return yuv;
}

public static byte[] rotateYUV420Degree270(byte[] data, int imageWidth,
                                     int imageHeight) {
    byte[] yuv = new byte[imageWidth * imageHeight * 3 / 2];
    int nWidth = 0, nHeight = 0;
    int wh = 0;
    int uvHeight = 0;
    if (imageWidth != nWidth || imageHeight != nHeight) {
        nWidth = imageWidth;
        nHeight = imageHeight;
        wh = imageWidth * imageHeight;
        uvHeight = imageHeight >> 1;// uvHeight = height / 2
    }
    // ??Y
    int k = 0;
    for (int i = 0; i < imageWidth; i++) {
        int nPos = 0;
        for (int j = 0; j < imageHeight; j++) {
            yuv[k] = data[nPos + i];
            k++;
            nPos += imageWidth;
        }
    }
    for (int i = 0; i < imageWidth; i += 2) {
        int nPos = wh;
        for (int j = 0; j < uvHeight; j++) {
            yuv[k] = data[nPos + i];
            yuv[k + 1] = data[nPos + i + 1];
            k += 2;
            nPos += imageWidth;
        }
    }
    return rotateYUV420Degree180(yuv, imageWidth, imageHeight);
}