j = zigzag_direct[i];
j = s->scantable.permutated[i];
static int mjpeg_decode_dqt(MJpegDecodeContext *s,                            UINT8 *buf, int buf_size){    int len, index, i, j;    init_get_bits(&s->gb, buf, buf_size);        len = get_bits(&s->gb, 16) - 2;    while (len >= 65) {        /* only 8 bit precision handled */        if (get_bits(&s->gb, 4) != 0)	{	    dprintf("dqt: 16bit precision\n");            return -1;	}        index = get_bits(&s->gb, 4);        if (index >= 4)            return -1;        dprintf("index=%d\n", index);        /* read quant table */        for(i=0;i<64;i++) {            j = zigzag_direct[i];	    s->quant_matrixes[index][j] = get_bits(&s->gb, 8);        }        len -= 65;    }        SKIP_REMAINING(&s->gb, len);    return 0;}