src/main/java/org/jcodec/codecs/mpeg12/MPEGPredDbl.java
@Override
    public void predictPlane(byte[] ref, int refX, int refY, int refW, int refH, int refVertStep, int refVertOff,
            int[] tgt, int tgtY, int tgtW, int tgtH, int tgtVertStep) {
        super.predictPlane(ref, refX << 1, refY << 1, refW, refH, refVertStep, refVertOff, tgt, tgtY, tgtW << 2, tgtH << 2,
                tgtVertStep);
    }
@Override
    public void predictPlane(byte[] ref, int refX, int refY, int refW, int refH, int refVertStep, int refVertOff,
            int[] tgt, int tgtY, int tgtW, int tgtH, int tgtVertStep) {
        super.predictPlane(ref, refX << 1, refY << 1, refW, refH, refVertStep, refVertOff, tgt, tgtY, tgtW << 2, tgtH << 2,
                tgtVertStep);
    }
this may be a result of color greening out in long GOPs.