src/main/java/org/jcodec/common/dct/SparseIDCT.java
public static final void start(int[] block, int dc) {
        dc <<= DC_SHIFT;
        for (int i = 0; i < 64; i += 4) {
            block[i + 0] = dc;
            block[i + 1] = dc;
            block[i + 2] = dc;
            block[i + 3] = dc;
        }
    }
public static final void start(int[] block, int dc) {
        dc <<= DC_SHIFT;
        for (int i = 0; i < 64; i += 4) {
            block[i + 0] = dc;
            block[i + 1] = dc;
            block[i + 2] = dc;
            block[i + 3] = dc;
        }
    }
Starts DCT reconstruction

Faster then call to 'coeff' with ind = 0

@param block
@param dc