jrevdct.c

tcpmp播放器的flv插件

		    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_275899380);
		    z3 = MULTIPLY(-d7, FIX_1_961570560);
		    tmp0 = MULTIPLY(-d7, FIX_1_662939225); 
		    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_275899380);
		}
	    }
	}
    } 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_509795579);
		    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_275899380);
		    tmp3 = MULTIPLY(d3, FIX_1_175875602);
		}
	    } else {
		if (d1) {
		    /* d1 != 0, d3 == 0, d5 == 0, d7 == 0 */
		    tmp0 = MULTIPLY(d1, FIX_0_275899380);
		    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[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0,
					   CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0,
					   CONST_BITS+PASS1_BITS+3);
    
    dataptr++;			/* advance pointer to next column */
  }
}

#undef DCTSIZE
#define DCTSIZE 4
#define DCTSTRIDE 8

void j_rev_dct4(DCTBLOCK data)
{
  int32_t tmp0, tmp1, tmp2, tmp3;
  int32_t tmp10, tmp11, tmp12, tmp13;
  int32_t z1;
  int32_t d0, d2, d4, d6;
  register DCTELEM *dataptr;
  int rowctr;

  /* Pass 1: process rows. */
  /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
  /* furthermore, we scale the results by 2**PASS1_BITS. */

  data[0] += 4;
  
  dataptr = data;

  for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
    /* Due to quantization, we will usually find that many of the input
     * coefficients are zero, especially the AC terms.  We can exploit this
     * by short-circuiting the IDCT calculation for any row in which all
     * the AC terms are zero.  In that case each output is equal to the
     * DC coefficient (with scale factor as needed).
     * With typical images and quantization tables, half or more of the
     * row DCT calculations can be simplified this way.
     */

    register int *idataptr = (int*)dataptr;

    d0 = dataptr[0];
    d2 = dataptr[1];
    d4 = dataptr[2];
    d6 = dataptr[3];

    if ((d2 | d4 | d6) == 0) {
      /* AC terms all zero */
      if (d0) {
	  /* Compute a 32 bit value to assign. */
	  DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS);
	  register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000);
	  
	  idataptr[0] = v;
	  idataptr[1] = v;
      }
      
      dataptr += DCTSTRIDE;	/* advance pointer to next row */
      continue;
    }
    
    /* Even part: reverse the even part of the forward DCT. */
    /* The rotator is sqrt(2)*c(-6). */
    if (d6) {
	    if (d2) {
		    /* 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 */
		    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 {
	    if (d2) {
		    /* 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 */
		    tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
		    tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
	    }
      }

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

    dataptr[0] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
    dataptr[1] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
    dataptr[2] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
    dataptr[3] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);

    dataptr += DCTSTRIDE;		/* 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[DCTSTRIDE*0];
    d2 = dataptr[DCTSTRIDE*1];
    d4 = dataptr[DCTSTRIDE*2];
    d6 = dataptr[DCTSTRIDE*3];

    /* Even part: reverse the even part of the forward DCT. */
    /* The rotator is sqrt(2)*c(-6). */
    if (d6) {
	    if (d2) {
		    /* 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 */
		    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 {
	    if (d2) {
		    /* 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 */
		    tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
		    tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
	    }
    }

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

    dataptr[DCTSTRIDE*0] = tmp10 >> (CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSTRIDE*1] = tmp11 >> (CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSTRIDE*2] = tmp12 >> (CONST_BITS+PASS1_BITS+3);
    dataptr[DCTSTRIDE*3] = tmp13 >> (CONST_BITS+PASS1_BITS+3);
    
    dataptr++;			/* advance pointer to next column */
  }
}

void j_rev_dct2(DCTBLOCK data){
  int d00, d01, d10, d11;

  data[0] += 4;
  d00 = data[0+0*DCTSTRIDE] + data[1+0*DCTSTRIDE];
  d01 = data[0+0*DCTSTRIDE] - data[1+0*DCTSTRIDE];
  d10 = data[0+1*DCTSTRIDE] + data[1+1*DCTSTRIDE];
  d11 = data[0+1*DCTSTRIDE] - data[1+1*DCTSTRIDE];
 
  data[0+0*DCTSTRIDE]= (d00 + d10)>>3;
  data[1+0*DCTSTRIDE]= (d01 + d11)>>3;
  data[0+1*DCTSTRIDE]= (d00 - d10)>>3;
  data[1+1*DCTSTRIDE]= (d01 - d11)>>3;
}

void j_rev_dct1(DCTBLOCK data){
  data[0] = (data[0] + 4)>>3;
}

#undef FIX
#undef CONST_BITS