src/main/java/org/jcodec/codecs/h264/decode/BlockInterpolator.java
void getLuma31(byte[] pels, int picW, byte[] blk, int blkOff, int blkStride, int x, int y, int blkW,
            int blkH) {
        getLuma20(pels, picW, blk, blkOff, blkStride, x, y, blkW, blkH);
        getLuma02(pels, picW, tmp3, 0, blkW, x + 1, y, blkW, blkH);

        merge(blk, tmp3, blkOff, blkStride, blkW, blkH);
    }
void getLuma31(byte[] pels, int picW, byte[] blk, int blkOff, int blkStride, int x, int y, int blkW,
            int blkH) {
        getLuma20(pels, picW, blk, blkOff, blkStride, x, y, blkW, blkH);
        getLuma02(pels, picW, tmp3, 0, blkW, x + 1, y, blkW, blkH);

        merge(blk, tmp3, blkOff, blkStride, blkW, blkH);
    }
void getLuma31 ( byte [ ] pels , int picW , byte [ ] blk , int blkOff , int blkStride , int x , int y , int blkW , int blkH ) { getLuma20 ( pels , picW , blk , blkOff , blkStride , x , y , blkW , blkH ) ; getLuma02 ( pels , picW , tmp3 , 0 , blkW , x + 1 , y , blkW , blkH ) ; merge ( blk , tmp3 , blkOff , blkStride , blkW , blkH ) ; }
Qpel horizontal, Qpel vertical (3, 1)
Qpel horizontal Qpel vertical ( 3 1 )