jrevdct.c

32位操作系统OS/2的MPEG播放机

		    z2 = MULTIPLY(z2, - FIX(2.562915447));
		    z3 = MULTIPLY(z3, - FIX(1.961570560));
		    z4 = MULTIPLY(z4, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z1 + z3;
		    tmp1 += z2 + z4;
		    tmp2 += z2 + z3;
		    tmp3 += z1 + z4;
		} else {
		    /* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
		    z1 = d7;
		    z2 = d5 + d3;
		    z3 = d7 + d3;
		    z5 = MULTIPLY(z3 + d5, FIX(1.175875602));
		    
		    tmp0 = MULTIPLY(d7, FIX(0.298631336)); 
		    tmp1 = MULTIPLY(d5, FIX(2.053119869));
		    tmp2 = MULTIPLY(d3, FIX(3.072711026));
		    z1 = MULTIPLY(d7, - FIX(0.899976223));
		    z2 = MULTIPLY(z2, - FIX(2.562915447));
		    z3 = MULTIPLY(z3, - FIX(1.961570560));
		    z4 = MULTIPLY(d5, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z1 + z3;
		    tmp1 += z2 + z4;
		    tmp2 += z2 + z3;
		    tmp3 = z1 + z4;
		}
	    } else {
		if (d1) {
		    /* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
		    z1 = d7 + d1;
		    z2 = d5;
		    z3 = d7;
		    z4 = d5 + d1;
		    z5 = MULTIPLY(z3 + z4, FIX(1.175875602));
		    
		    tmp0 = MULTIPLY(d7, FIX(0.298631336)); 
		    tmp1 = MULTIPLY(d5, FIX(2.053119869));
		    tmp3 = MULTIPLY(d1, FIX(1.501321110));
		    z1 = MULTIPLY(z1, - FIX(0.899976223));
		    z2 = MULTIPLY(d5, - FIX(2.562915447));
		    z3 = MULTIPLY(d7, - FIX(1.961570560));
		    z4 = MULTIPLY(z4, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z1 + z3;
		    tmp1 += z2 + z4;
		    tmp2 = z2 + z3;
		    tmp3 += z1 + z4;
		} else {
		    /* d1 == 0, d3 == 0, d5 != 0, d7 != 0 */
		    tmp0 = MULTIPLY(d7, - FIX(0.601344887)); 
		    z1 = MULTIPLY(d7, - FIX(0.899976223));
		    z3 = MULTIPLY(d7, - FIX(1.961570560));
		    tmp1 = MULTIPLY(d5, - FIX(0.509795578));
		    z2 = MULTIPLY(d5, - FIX(2.562915447));
		    z4 = MULTIPLY(d5, - FIX(0.390180644));
		    z5 = MULTIPLY(d5 + d7, FIX(1.175875602));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z3;
		    tmp1 += z4;
		    tmp2 = z2 + z3;
		    tmp3 = z1 + z4;
		}
	    }
	} else {
	    if (d3) {
		if (d1) {
		    /* d1 != 0, d3 != 0, d5 == 0, d7 != 0 */
		    z1 = d7 + d1;
		    z3 = d7 + d3;
		    z5 = MULTIPLY(z3 + d1, FIX(1.175875602));
		    
		    tmp0 = MULTIPLY(d7, FIX(0.298631336)); 
		    tmp2 = MULTIPLY(d3, FIX(3.072711026));
		    tmp3 = MULTIPLY(d1, FIX(1.501321110));
		    z1 = MULTIPLY(z1, - FIX(0.899976223));
		    z2 = MULTIPLY(d3, - FIX(2.562915447));
		    z3 = MULTIPLY(z3, - FIX(1.961570560));
		    z4 = MULTIPLY(d1, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z1 + z3;
		    tmp1 = z2 + z4;
		    tmp2 += z2 + z3;
		    tmp3 += z1 + z4;
		} else {
		    /* d1 == 0, d3 != 0, d5 == 0, d7 != 0 */
		    z3 = d7 + d3;
		    
		    tmp0 = MULTIPLY(d7, - FIX(0.601344887)); 
		    z1 = MULTIPLY(d7, - FIX(0.899976223));
		    tmp2 = MULTIPLY(d3, FIX(0.509795579));
		    z2 = MULTIPLY(d3, - FIX(2.562915447));
		    z5 = MULTIPLY(z3, FIX(1.175875602));
		    z3 = MULTIPLY(z3, - FIX(0.785694958));
		    
		    tmp0 += z3;
		    tmp1 = z2 + z5;
		    tmp2 += z3;
		    tmp3 = z1 + z5;
		}
	    } else {
		if (d1) {
		    /* d1 != 0, d3 == 0, d5 == 0, d7 != 0 */
		    z1 = d7 + d1;
		    z5 = MULTIPLY(z1, FIX(1.175875602));

		    z1 = MULTIPLY(z1, FIX(0.275899379));
		    z3 = MULTIPLY(d7, - FIX(1.961570560));
		    tmp0 = MULTIPLY(d7, - FIX(1.662939224)); 
		    z4 = MULTIPLY(d1, - FIX(0.390180644));
		    tmp3 = MULTIPLY(d1, FIX(1.111140466));

		    tmp0 += z1;
		    tmp1 = z4 + z5;
		    tmp2 = z3 + z5;
		    tmp3 += z1;
		} else {
		    /* d1 == 0, d3 == 0, d5 == 0, d7 != 0 */
		    tmp0 = MULTIPLY(d7, - FIX(1.387039845));
		    tmp1 = MULTIPLY(d7, FIX(1.175875602));
		    tmp2 = MULTIPLY(d7, - FIX(0.785694958));
		    tmp3 = MULTIPLY(d7, FIX(0.275899379));
		}
	    }
	}
    } else {
	if (d5) {
	    if (d3) {
		if (d1) {
		    /* d1 != 0, d3 != 0, d5 != 0, d7 == 0 */
		    z2 = d5 + d3;
		    z4 = d5 + d1;
		    z5 = MULTIPLY(d3 + z4, FIX(1.175875602));
		    
		    tmp1 = MULTIPLY(d5, FIX(2.053119869));
		    tmp2 = MULTIPLY(d3, FIX(3.072711026));
		    tmp3 = MULTIPLY(d1, FIX(1.501321110));
		    z1 = MULTIPLY(d1, - FIX(0.899976223));
		    z2 = MULTIPLY(z2, - FIX(2.562915447));
		    z3 = MULTIPLY(d3, - FIX(1.961570560));
		    z4 = MULTIPLY(z4, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 = z1 + z3;
		    tmp1 += z2 + z4;
		    tmp2 += z2 + z3;
		    tmp3 += z1 + z4;
		} else {
		    /* d1 == 0, d3 != 0, d5 != 0, d7 == 0 */
		    z2 = d5 + d3;
		    
		    z5 = MULTIPLY(z2, FIX(1.175875602));
		    tmp1 = MULTIPLY(d5, FIX(1.662939225));
		    z4 = MULTIPLY(d5, - FIX(0.390180644));
		    z2 = MULTIPLY(z2, - FIX(1.387039845));
		    tmp2 = MULTIPLY(d3, FIX(1.111140466));
		    z3 = MULTIPLY(d3, - FIX(1.961570560));
		    
		    tmp0 = z3 + z5;
		    tmp1 += z2;
		    tmp2 += z2;
		    tmp3 = z4 + z5;
		}
	    } else {
		if (d1) {
		    /* d1 != 0, d3 == 0, d5 != 0, d7 == 0 */
		    z4 = d5 + d1;
		    
		    z5 = MULTIPLY(z4, FIX(1.175875602));
		    z1 = MULTIPLY(d1, - FIX(0.899976223));
		    tmp3 = MULTIPLY(d1, FIX(0.601344887));
		    tmp1 = MULTIPLY(d5, - FIX(0.509795578));
		    z2 = MULTIPLY(d5, - FIX(2.562915447));
		    z4 = MULTIPLY(z4, FIX(0.785694958));
		    
		    tmp0 = z1 + z5;
		    tmp1 += z4;
		    tmp2 = z2 + z5;
		    tmp3 += z4;
		} else {
		    /* d1 == 0, d3 == 0, d5 != 0, d7 == 0 */
		    tmp0 = MULTIPLY(d5, FIX(1.175875602));
		    tmp1 = MULTIPLY(d5, FIX(0.275899380));
		    tmp2 = MULTIPLY(d5, - FIX(1.387039845));
		    tmp3 = MULTIPLY(d5, FIX(0.785694958));
		}
	    }
	} else {
	    if (d3) {
		if (d1) {
		    /* d1 != 0, d3 != 0, d5 == 0, d7 == 0 */
		    z5 = d1 + d3;
		    tmp3 = MULTIPLY(d1, FIX(0.211164243));
		    tmp2 = MULTIPLY(d3, - FIX(1.451774981));
		    z1 = MULTIPLY(d1, FIX(1.061594337));
		    z2 = MULTIPLY(d3, - FIX(2.172734803));
		    z4 = MULTIPLY(z5, FIX(0.785694958));
		    z5 = MULTIPLY(z5, FIX(1.175875602));
		    
		    tmp0 = z1 - z4;
		    tmp1 = z2 + z4;
		    tmp2 += z5;
		    tmp3 += z5;
		} else {
		    /* d1 == 0, d3 != 0, d5 == 0, d7 == 0 */
		    tmp0 = MULTIPLY(d3, - FIX(0.785694958));
		    tmp1 = MULTIPLY(d3, - FIX(1.387039845));
		    tmp2 = MULTIPLY(d3, - FIX(0.275899379));
		    tmp3 = MULTIPLY(d3, FIX(1.175875602));
		}
	    } else {
		if (d1) {
		    /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
		    tmp0 = MULTIPLY(d1, FIX(0.275899379));
		    tmp1 = MULTIPLY(d1, FIX(0.785694958));
		    tmp2 = MULTIPLY(d1, FIX(1.175875602));
		    tmp3 = MULTIPLY(d1, FIX(1.387039845));
		} else {
		    /* d1 == 0, d3 == 0, d5 == 0, d7 == 0 */
		    tmp0 = tmp1 = tmp2 = tmp3 = 0;
		}
	    }
	}
    }

    /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */

    dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
    dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
    dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
    dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
    dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
    dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
    dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
    dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);

    dataptr += DCTSIZE;		/* advance pointer to next row */
  }

  /* Pass 2: process columns. */
  /* Note that we must descale the results by a factor of 8 == 2**3, */
  /* and also undo the PASS1_BITS scaling. */

  dataptr = data;
  for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
    /* Columns of zeroes can be exploited in the same way as we did with rows.
     * However, the row calculation has created many nonzero AC terms, so the
     * simplification applies less often (typically 5% to 10% of the time).
     * On machines with very fast multiplication, it's possible that the
     * test takes more time than it's worth.  In that case this section
     * may be commented out.
     */

    d0 = dataptr[DCTSIZE*0];
    d1 = dataptr[DCTSIZE*1];
    d2 = dataptr[DCTSIZE*2];
    d3 = dataptr[DCTSIZE*3];
    d4 = dataptr[DCTSIZE*4];
    d5 = dataptr[DCTSIZE*5];
    d6 = dataptr[DCTSIZE*6];
    d7 = dataptr[DCTSIZE*7];

    /* Even part: reverse the even part of the forward DCT. */
    /* The rotator is sqrt(2)*c(-6). */
    if (d6) {
	if (d4) {
	    if (d2) {
		if (d0) {
		    /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
		    z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
		    tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
		    tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));

		    tmp0 = (d0 + d4) << CONST_BITS;
		    tmp1 = (d0 - d4) << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp1 + tmp2;
		    tmp12 = tmp1 - tmp2;
		} else {
		    /* d0 == 0, d2 != 0, d4 != 0, d6 != 0 */
		    z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
		    tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
		    tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));

		    tmp0 = d4 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp2 - tmp0;
		    tmp12 = -(tmp0 + tmp2);
		}
	    } else {
		if (d0) {
		    /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
		    tmp2 = MULTIPLY(d6, - FIX(1.306562965));
		    tmp3 = MULTIPLY(d6, FIX(0.541196100));

		    tmp0 = (d0 + d4) << CONST_BITS;
		    tmp1 = (d0 - d4) << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp1 + tmp2;
		    tmp12 = tmp1 - tmp2;
		} else {
		    /* d0 == 0, d2 == 0, d4 != 0, d6 != 0 */
		    tmp2 = MULTIPLY(d6, -FIX(1.306562965));
		    tmp3 = MULTIPLY(d6, FIX(0.541196100));

		    tmp0 = d4 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp2 - tmp0;
		    tmp12 = -(tmp0 + tmp2);
		}
	    }
	} else {
	    if (d2) {
		if (d0) {
		    /* d0 != 0, d2 != 0, d4 == 0, d6 != 0 */
		    z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
		    tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
		    tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));

		    tmp0 = d0 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp0 + tmp2;
		    tmp12 = tmp0 - tmp2;
		} else {
		    /* d0 == 0, d2 != 0, d4 == 0, d6 != 0 */
		    z1 = MULTIPLY(d2 + d6, FIX(0.541196100));
		    tmp2 = z1 + MULTIPLY(d6, - FIX(1.847759065));
		    tmp3 = z1 + MULTIPLY(d2, FIX(0.765366865));

		    tmp10 = tmp3;
		    tmp13 = -tmp3;
		    tmp11 = tmp2;
		    tmp12 = -tmp2;
		}
	    } else {
		if (d0) {
		    /* d0 != 0, d2 == 0, d4 == 0, d6 != 0 */
		    tmp2 = MULTIPLY(d6, - FIX(1.306562965));
		    tmp3 = MULTIPLY(d6, FIX(0.541196100));

		    tmp0 = d0 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp0 + tmp2;
		    tmp12 = tmp0 - tmp2;
		} else {
		    /* d0 == 0, d2 == 0, d4 == 0, d6 != 0 */
		    tmp2 = MULTIPLY(d6, - FIX(1.306562965));
		    tmp3 = MULTIPLY(d6, FIX(0.541196100));

		    tmp10 = tmp3;
		    tmp13 = -tmp3;
		    tmp11 = tmp2;
		    tmp12 = -tmp2;
		}
	    }
	}
    } else {
	if (d4) {
	    if (d2) {
		if (d0) {
		    /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
		    tmp2 = MULTIPLY(d2, FIX(0.541196100));
		    tmp3 = MULTIPLY(d2, FIX(1.306562965));

		    tmp0 = (d0 + d4) << CONST_BITS;
		    tmp1 = (d0 - d4) << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp1 + tmp2;
		    tmp12 = tmp1 - tmp2;
		} else {
		    /* d0 == 0, d2 != 0, d4 != 0, d6 == 0 */
		    tmp2 = MULTIPLY(d2, FIX(0.541196100));
		    tmp3 = MULTIPLY(d2, FIX(1.306562965));

		    tmp0 = d4 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp2 - tmp0;
		    tmp12 = -(tmp0 + tmp2);
		}
	    } else {
		if (d0) {
		    /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
		    tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
		    tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
		} else {
		    /* d0 == 0, d2 == 0, d4 != 0, d6 == 0 */
		    tmp10 = tmp13 = d4 << CONST_BITS;
		    tmp11 = tmp12 = -tmp10;
		}
	    }
	} else {
	    if (d2) {
		if (d0) {
		    /* d0 != 0, d2 != 0, d4 == 0, d6 == 0 */
		    tmp2 = MULTIPLY(d2, FIX(0.541196100));
		    tmp3 = MULTIPLY(d2, FIX(1.306562965));

		    tmp0 = d0 << CONST_BITS;

		    tmp10 = tmp0 + tmp3;
		    tmp13 = tmp0 - tmp3;
		    tmp11 = tmp0 + tmp2;
		    tmp12 = tmp0 - tmp2;
		} else {
		    /* d0 == 0, d2 != 0, d4 == 0, d6 == 0 */
		    tmp2 = MULTIPLY(d2, FIX(0.541196100));
		    tmp3 = MULTIPLY(d2, FIX(1.306562965));

		    tmp10 = tmp3;
		    tmp13 = -tmp3;
		    tmp11 = tmp2;
		    tmp12 = -tmp2;
		}
	    } else {
		if (d0) {
		    /* d0 != 0, d2 == 0, d4 == 0, d6 == 0 */
		    tmp10 = tmp13 = tmp11 = tmp12 = d0 << CONST_BITS;
		} else {
		    /* d0 == 0, d2 == 0, d4 == 0, d6 == 0 */
		    tmp10 = tmp13 = tmp11 = tmp12 = 0;
		}
	    }
	}
    }

    /* Odd part per figure 8; the matrix is unitary and hence its
     * transpose is its inverse.  i0..i3 are y7,y5,y3,y1 respectively.
     */
    if (d7) {
	if (d5) {
	    if (d3) {
		if (d1) {
		    /* d1 != 0, d3 != 0, d5 != 0, d7 != 0 */
		    z1 = d7 + d1;
		    z2 = d5 + d3;
		    z3 = d7 + d3;
		    z4 = d5 + d1;
		    z5 = MULTIPLY(z3 + z4, FIX(1.175875602));
		    
		    tmp0 = MULTIPLY(d7, FIX(0.298631336)); 
		    tmp1 = MULTIPLY(d5, FIX(2.053119869));
		    tmp2 = MULTIPLY(d3, FIX(3.072711026));
		    tmp3 = MULTIPLY(d1, FIX(1.501321110));
		    z1 = MULTIPLY(z1, - FIX(0.899976223));
		    z2 = MULTIPLY(z2, - FIX(2.562915447));
		    z3 = MULTIPLY(z3, - FIX(1.961570560));
		    z4 = MULTIPLY(z4, - FIX(0.390180644));
		    
		    z3 += z5;
		    z4 += z5;
		    
		    tmp0 += z1 + z3;
		    tmp1 += z2 + z4;
		    tmp2 += z2 + z3;