Apps Different code(.java file) for different platform?

[Rudba556]

I have a code where image data is passed from bitmap to FFmpeg frame recorder and converted to a video. But i need to make small changes while running it on LG G3(armv7) from Asus zenfone 5(x86).

Following are the class variables that create the issuedeclared under, class Main Activity)

inputWidth = 1024;
inputHeight = 650;

Following is the method where the issue occurs:

 byte [] getNV21(int inputWidth, int inputHeight, Bitmap bitmap) {

        int [] argb = new int[inputWidth * inputHeight];

        bitmap.getPixels(argb, 0, inputWidth, 0, 0, inputWidth, inputHeight);

        byte [] yuv = new byte[inputWidth*inputHeight*3/2];
        encodeYUV420SP(yuv, argb, inputWidth, inputHeight);

        return yuv;
    }

    void encodeYUV420SP(byte[] yuv420sp, int[] argb, int width, int height) {
        final int frameSize = width * height;

        int yIndex = 0;
        int uvIndex = frameSize;

        int a, R, G, B, Y, U, V;
        int index = 0;
        for (int j = 0; j < height; j++) {
            for (int i = 0; i < width; i++) {

                a = (argb[index] & 0xff000000) >> 24; // a is not used obviously
                R = (argb[index] & 0xff0000) >> 16;
                G = (argb[index] & 0xff00) >> 8;
                B = (argb[index] & 0xff) >> 0;

                // well known RGB to YUV algorithm
                Y = ( (  66 * R + 129 * G +  25 * B + 128) >> 8) +  16;
                U = ( ( -38 * R -  74 * G + 112 * B + 128) >> 8) + 128;
                V = ( ( 112 * R -  94 * G -  18 * B + 128) >> 8) + 128;

                // NV21 has a plane of Y and interleaved planes of VU each sampled by a factor of 2
                //    meaning for every 4 Y pixels there are 1 V and 1 U.  Note the sampling is every other
                //    pixel AND every other scanline.
                yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
                if (j % 2 == 0 && index % 2 == 0) {
                    yuv420sp[uvIndex++] = (byte)((V<0) ? 0 : ((V > 255) ? 255 : V));
                    yuv420sp[uvIndex++] = (byte)((U<0) ? 0 : ((U > 255) ? 255 : U));
                }

                index ++;
            }
        }
    }

Working CODE:
LG G3 :I can use the above variables at any place in the code to get the required output.
Bitmap size returned = 2734200

Asus Zenfone 5: Except at creating the bitmap, I have to use everywhere else bitmap.getHeight() and bitmap.getWidth(), to get the required output.
Surprisingly here Bitmap size returned = 725760

INCORRECT CODE:
LG G3 : IF i use bitmap.getHeight() and bitmap.getWidth(), i get java.lang.ArrayIndexOutOfBoundsException: length = 102354 , index = 102354. @getNV21 method

Asus Zenfone 5 : If i use inputWidth , inputHeight i get
java.lang.IllegalArgumentException: x + width must be <= bitmap.width() @getNV21 method

How can i generalize the above code for both phones?