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modules/javafx.graphics/src/main/native-iio/libjpeg7/jidctint.c
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@@ -1,10 +1,10 @@
/*
* jidctint.c
*
* Copyright (C) 1991-1998, Thomas G. Lane.
- * Modification developed 2002-2009 by Guido Vollbeding.
+ * Modification developed 2002-2016 by Guido Vollbeding.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains a slow-but-accurate integer implementation of the
* inverse DCT (Discrete Cosine Transform). In the IJG code, this routine
@@ -163,10 +163,13 @@
#define DEQUANTIZE(coef,quantval) (((ISLOW_MULT_TYPE) (coef)) * (quantval))
/*
* Perform dequantization and inverse DCT on one block of coefficients.
+ *
+ * Optimized algorithm with 12 multiplications in the 1-D kernel.
+ * cK represents sqrt(2) * cos(K*pi/16).
*/
GLOBAL(void)
jpeg_idct_islow (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
@@ -182,13 +185,14 @@
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[DCTSIZE2]; /* buffers data between passes */
SHIFT_TEMPS
- /* Pass 1: process columns from input, store into work array. */
- /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
+ /* Pass 1: process columns from input, store into work array.
+ * Note results are scaled up by sqrt(8) compared to a true IDCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; ctr--) {
@@ -221,19 +225,13 @@
quantptr++;
wsptr++;
continue;
}
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
- z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
z2 <<= CONST_BITS;
z3 <<= CONST_BITS;
@@ -241,10 +239,17 @@
z2 += ONE << (CONST_BITS-PASS1_BITS-1);
tmp0 = z2 + z3;
tmp1 = z2 - z3;
+ z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -258,25 +263,25 @@
tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -292,17 +297,24 @@
inptr++; /* advance pointers to next column */
quantptr++;
wsptr++;
}
- /* Pass 2: process rows from work array, store into output array. */
- /* Note that we must descale the results by a factor of 8 == 2**3, */
- /* and also undo the PASS1_BITS scaling. */
+ /* Pass 2: process rows from work array, store into output array.
+ * Note that we must descale the results by a factor of 8 == 2**3,
+ * and also undo the PASS1_BITS scaling.
+ */
wsptr = workspace;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
outptr = output_buf[ctr] + output_col;
+
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z2 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
+
/* Rows of zeroes can be exploited in the same way as we did with columns.
* However, the column 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
@@ -311,11 +323,11 @@
#ifndef NO_ZERO_ROW_TEST
if (wsptr[1] == 0 && wsptr[2] == 0 && wsptr[3] == 0 && wsptr[4] == 0 &&
wsptr[5] == 0 && wsptr[6] == 0 && wsptr[7] == 0) {
/* AC terms all zero */
- JSAMPLE dcval = range_limit[(int) DESCALE((INT32) wsptr[0], PASS1_BITS+3)
+ JSAMPLE dcval = range_limit[(int) RIGHT_SHIFT(z2, PASS1_BITS+3)
& RANGE_MASK];
outptr[0] = dcval;
outptr[1] = dcval;
outptr[2] = dcval;
@@ -328,27 +340,26 @@
wsptr += DCTSIZE; /* advance pointer to next row */
continue;
}
#endif
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = (INT32) wsptr[2];
- z3 = (INT32) wsptr[6];
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
- /* Add fudge factor here for final descale. */
- z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
z3 = (INT32) wsptr[4];
tmp0 = (z2 + z3) << CONST_BITS;
tmp1 = (z2 - z3) << CONST_BITS;
+ z2 = (INT32) wsptr[2];
+ z3 = (INT32) wsptr[6];
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -362,25 +373,25 @@
tmp3 = (INT32) wsptr[1];
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -416,11 +427,11 @@
#ifdef IDCT_SCALING_SUPPORTED
/*
* Perform dequantization and inverse DCT on one block of coefficients,
- * producing a 7x7 output block.
+ * producing a reduced-size 7x7 output block.
*
* Optimized algorithm with 12 multiplications in the 1-D kernel.
* cK represents sqrt(2) * cos(K*pi/14).
*/
@@ -500,12 +511,14 @@
for (ctr = 0; ctr < 7; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp13 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp13 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp13 <<= CONST_BITS;
z1 = (INT32) wsptr[2];
z2 = (INT32) wsptr[4];
z3 = (INT32) wsptr[6];
@@ -636,12 +649,14 @@
for (ctr = 0; ctr < 6; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
tmp2 = (INT32) wsptr[4];
tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */
tmp1 = tmp0 + tmp10;
tmp11 = tmp0 - tmp10 - tmp10;
@@ -755,12 +770,14 @@
for (ctr = 0; ctr < 5; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp12 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp12 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp12 <<= CONST_BITS;
tmp0 = (INT32) wsptr[2];
tmp1 = (INT32) wsptr[4];
z1 = MULTIPLY(tmp0 + tmp1, FIX(0.790569415)); /* (c2+c4)/2 */
z2 = MULTIPLY(tmp0 - tmp1, FIX(0.353553391)); /* (c2-c4)/2 */
@@ -867,12 +884,14 @@
for (ctr = 0; ctr < 4; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp2 = (INT32) wsptr[2];
tmp10 = (tmp0 + tmp2) << CONST_BITS;
tmp12 = (tmp0 - tmp2) << CONST_BITS;
@@ -964,12 +983,14 @@
for (ctr = 0; ctr < 3; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
tmp2 = (INT32) wsptr[2];
tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */
tmp10 = tmp0 + tmp12;
tmp2 = tmp0 - tmp12 - tmp12;
@@ -1006,25 +1027,25 @@
GLOBAL(void)
jpeg_idct_2x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
- INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
+ DCTELEM tmp0, tmp1, tmp2, tmp3, tmp4, tmp5;
ISLOW_MULT_TYPE * quantptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
- SHIFT_TEMPS
+ ISHIFT_TEMPS
/* Pass 1: process columns from input. */
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
/* Column 0 */
tmp4 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp5 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]);
- /* Add fudge factor here for final descale. */
- tmp4 += ONE << 2;
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp4 += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2);
tmp0 = tmp4 + tmp5;
tmp2 = tmp4 - tmp5;
/* Column 1 */
@@ -1037,18 +1058,18 @@
/* Pass 2: process 2 rows, store into output array. */
/* Row 0 */
outptr = output_buf[0] + output_col;
- outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK];
- outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK];
+ outptr[0] = range_limit[(int) IRIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK];
+ outptr[1] = range_limit[(int) IRIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK];
/* Row 1 */
outptr = output_buf[1] + output_col;
- outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp2 + tmp3, 3) & RANGE_MASK];
- outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp2 - tmp3, 3) & RANGE_MASK];
+ outptr[0] = range_limit[(int) IRIGHT_SHIFT(tmp2 + tmp3, 3) & RANGE_MASK];
+ outptr[1] = range_limit[(int) IRIGHT_SHIFT(tmp2 - tmp3, 3) & RANGE_MASK];
}
/*
* Perform dequantization and inverse DCT on one block of coefficients,
@@ -1061,21 +1082,25 @@
GLOBAL(void)
jpeg_idct_1x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
- int dcval;
+ DCTELEM dcval;
ISLOW_MULT_TYPE * quantptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
- SHIFT_TEMPS
+ ISHIFT_TEMPS
/* 1x1 is trivial: just take the DC coefficient divided by 8. */
+
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
+
dcval = DEQUANTIZE(coef_block[0], quantptr[0]);
- dcval = (int) DESCALE((INT32) dcval, 3);
+ /* Add range center and fudge factor for descale and range-limit. */
+ dcval += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2);
- output_buf[0][output_col] = range_limit[dcval & RANGE_MASK];
+ output_buf[0][output_col] =
+ range_limit[(int) IRIGHT_SHIFT(dcval, 3) & RANGE_MASK];
}
/*
* Perform dequantization and inverse DCT on one block of coefficients,
@@ -1170,12 +1195,14 @@
for (ctr = 0; ctr < 9; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
z1 = (INT32) wsptr[2];
z2 = (INT32) wsptr[4];
z3 = (INT32) wsptr[6];
@@ -1353,12 +1380,14 @@
for (ctr = 0; ctr < 10; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z3 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */
z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */
tmp10 = z3 + z1;
@@ -1546,12 +1575,14 @@
for (ctr = 0; ctr < 11; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp10 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp10 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp10 <<= CONST_BITS;
z1 = (INT32) wsptr[2];
z2 = (INT32) wsptr[4];
z3 = (INT32) wsptr[6];
@@ -1750,12 +1781,14 @@
for (ctr = 0; ctr < 12; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z3 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */
@@ -1971,12 +2004,14 @@
for (ctr = 0; ctr < 13; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z1 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z1 <<= CONST_BITS;
z2 = (INT32) wsptr[2];
z3 = (INT32) wsptr[4];
z4 = (INT32) wsptr[6];
@@ -2198,12 +2233,14 @@
for (ctr = 0; ctr < 14; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z1 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z1 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */
z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */
z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */
@@ -2430,12 +2467,14 @@
for (ctr = 0; ctr < 15; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z1 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z1 <<= CONST_BITS;
z2 = (INT32) wsptr[2];
z3 = (INT32) wsptr[4];
z4 = (INT32) wsptr[6];
@@ -2583,11 +2622,11 @@
/* Even part */
tmp0 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
tmp0 <<= CONST_BITS;
/* Add fudge factor here for final descale. */
- tmp0 += 1 << (CONST_BITS-PASS1_BITS-1);
+ tmp0 += ONE << (CONST_BITS-PASS1_BITS-1);
z1 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */
tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */
@@ -2681,12 +2720,14 @@
for (ctr = 0; ctr < 16; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
z1 = (INT32) wsptr[4];
tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */
tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */
@@ -2833,13 +2874,15 @@
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[8*8]; /* buffers data between passes */
SHIFT_TEMPS
- /* Pass 1: process columns from input, store into work array. */
- /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
+ /* Pass 1: process columns from input, store into work array.
+ * Note results are scaled up by sqrt(8) compared to a true IDCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = DCTSIZE; ctr > 0; ctr--) {
@@ -2872,19 +2915,13 @@
quantptr++;
wsptr++;
continue;
}
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
- z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
z2 <<= CONST_BITS;
z3 <<= CONST_BITS;
@@ -2892,10 +2929,17 @@
z2 += ONE << (CONST_BITS-PASS1_BITS-1);
tmp0 = z2 + z3;
tmp1 = z2 - z3;
+ z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -2909,25 +2953,25 @@
tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -2946,18 +2990,21 @@
}
/* Pass 2: process 8 rows from work array, store into output array.
* 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
z1 = (INT32) wsptr[4];
tmp1 = MULTIPLY(z1, FIX(1.306562965)); /* c4[16] = c2[8] */
tmp2 = MULTIPLY(z1, FIX_0_541196100); /* c12[16] = c6[8] */
@@ -3107,10 +3154,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -3162,18 +3210,21 @@
}
/* Pass 2: process 7 rows from work array, store into output array.
* 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 7; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z1 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z1 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z1 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z2 = MULTIPLY(z4, FIX(1.274162392)); /* c4 */
z3 = MULTIPLY(z4, FIX(0.314692123)); /* c12 */
z4 = MULTIPLY(z4, FIX(0.881747734)); /* c8 */
@@ -3302,10 +3353,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -3344,18 +3396,21 @@
}
/* Pass 2: process 6 rows from work array, store into output array.
* 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 6; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z3 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z4 = MULTIPLY(z4, FIX(1.224744871)); /* c4 */
@@ -3478,10 +3533,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -3518,18 +3574,21 @@
}
/* Pass 2: process 5 rows from work array, store into output array.
* 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 5; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- z3 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z3 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 <<= CONST_BITS;
z4 = (INT32) wsptr[4];
z1 = MULTIPLY(z4, FIX(1.144122806)); /* c4 */
z2 = MULTIPLY(z4, FIX(0.437016024)); /* c8 */
tmp10 = z3 + z1;
@@ -3637,12 +3696,14 @@
int ctr;
int workspace[8*4]; /* buffers data between passes */
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
- * 4-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ * 4-point IDCT kernel,
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -3673,35 +3734,40 @@
wsptr[8*3] = (int) (tmp10 - tmp0);
wsptr[8*1] = (int) (tmp12 + tmp2);
wsptr[8*2] = (int) (tmp12 - tmp2);
}
- /* Pass 2: process rows from work array, store into output array. */
- /* Note that we must descale the results by a factor of 8 == 2**3, */
- /* and also undo the PASS1_BITS scaling. */
+ /* Pass 2: process rows from work array, store into output array.
+ * Note that we must descale the results by a factor of 8 == 2**3,
+ * and also undo the PASS1_BITS scaling.
+ * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
wsptr = workspace;
for (ctr = 0; ctr < 4; ctr++) {
outptr = output_buf[ctr] + output_col;
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = (INT32) wsptr[2];
- z3 = (INT32) wsptr[6];
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
- /* Add fudge factor here for final descale. */
- z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z2 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 = (INT32) wsptr[4];
tmp0 = (z2 + z3) << CONST_BITS;
tmp1 = (z2 - z3) << CONST_BITS;
+ z2 = (INT32) wsptr[2];
+ z3 = (INT32) wsptr[6];
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -3715,25 +3781,25 @@
tmp3 = (INT32) wsptr[1];
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -3791,10 +3857,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 6; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -3821,18 +3888,21 @@
}
/* Pass 2: process 3 rows from work array, store into output array.
* 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 3; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
tmp2 = (INT32) wsptr[4];
tmp10 = MULTIPLY(tmp2, FIX(0.707106781)); /* c4 */
tmp1 = tmp0 + tmp10;
tmp11 = tmp0 - tmp10 - tmp10;
@@ -3922,18 +3992,19 @@
/* Pass 2: process 2 rows from work array, store into output array.
* 4-point IDCT kernel,
* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 2; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = wsptr[0] + (ONE << 2);
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = wsptr[0] + ((((INT32) RANGE_CENTER) << 3) + (ONE << 2));
tmp2 = wsptr[2];
tmp10 = (tmp0 + tmp2) << CONST_BITS;
tmp12 = (tmp0 - tmp2) << CONST_BITS;
@@ -3977,37 +4048,37 @@
GLOBAL(void)
jpeg_idct_2x1 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
- INT32 tmp0, tmp10;
+ DCTELEM tmp0, tmp1;
ISLOW_MULT_TYPE * quantptr;
JSAMPROW outptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
- SHIFT_TEMPS
+ ISHIFT_TEMPS
/* Pass 1: empty. */
/* Pass 2: process 1 row from input, store into output array. */
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
outptr = output_buf[0] + output_col;
/* Even part */
- tmp10 = DEQUANTIZE(coef_block[0], quantptr[0]);
- /* Add fudge factor here for final descale. */
- tmp10 += ONE << 2;
+ tmp0 = DEQUANTIZE(coef_block[0], quantptr[0]);
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2);
/* Odd part */
- tmp0 = DEQUANTIZE(coef_block[1], quantptr[1]);
+ tmp1 = DEQUANTIZE(coef_block[1], quantptr[1]);
/* Final output stage */
- outptr[0] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3) & RANGE_MASK];
- outptr[1] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3) & RANGE_MASK];
+ outptr[0] = range_limit[(int) IRIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK];
+ outptr[1] = range_limit[(int) IRIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK];
}
/*
* Perform dequantization and inverse DCT on one block of coefficients,
@@ -4034,10 +4105,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 16-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -4133,35 +4205,40 @@
wsptr[8*9] = (int) RIGHT_SHIFT(tmp26 - tmp12, CONST_BITS-PASS1_BITS);
wsptr[8*7] = (int) RIGHT_SHIFT(tmp27 + tmp13, CONST_BITS-PASS1_BITS);
wsptr[8*8] = (int) RIGHT_SHIFT(tmp27 - tmp13, CONST_BITS-PASS1_BITS);
}
- /* Pass 2: process rows from work array, store into output array. */
- /* Note that we must descale the results by a factor of 8 == 2**3, */
- /* and also undo the PASS1_BITS scaling. */
+ /* Pass 2: process rows from work array, store into output array.
+ * Note that we must descale the results by a factor of 8 == 2**3,
+ * and also undo the PASS1_BITS scaling.
+ * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
wsptr = workspace;
for (ctr = 0; ctr < 16; ctr++) {
outptr = output_buf[ctr] + output_col;
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = (INT32) wsptr[2];
- z3 = (INT32) wsptr[6];
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
- /* Add fudge factor here for final descale. */
- z2 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ z2 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
z3 = (INT32) wsptr[4];
tmp0 = (z2 + z3) << CONST_BITS;
tmp1 = (z2 - z3) << CONST_BITS;
+ z2 = (INT32) wsptr[2];
+ z3 = (INT32) wsptr[6];
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -4175,25 +4252,25 @@
tmp3 = (INT32) wsptr[1];
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -4252,10 +4329,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 14-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 7; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -4339,18 +4417,21 @@
}
/* Pass 2: process 14 rows from work array, store into output array.
* 7-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 14; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp23 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp23 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp23 <<= CONST_BITS;
z1 = (INT32) wsptr[2];
z2 = (INT32) wsptr[4];
z3 = (INT32) wsptr[6];
@@ -4435,10 +4516,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 12-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 6; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -4518,18 +4600,21 @@
}
/* Pass 2: process 12 rows from work array, store into output array.
* 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 12; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp10 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp10 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp10 <<= CONST_BITS;
tmp12 = (INT32) wsptr[4];
tmp20 = MULTIPLY(tmp12, FIX(0.707106781)); /* c4 */
tmp11 = tmp10 + tmp20;
tmp21 = tmp10 - tmp20 - tmp20;
@@ -4599,10 +4684,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 10-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 5; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -4674,18 +4760,21 @@
}
/* Pass 2: process 10 rows from work array, store into output array.
* 5-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 10; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp12 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp12 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp12 <<= CONST_BITS;
tmp13 = (INT32) wsptr[2];
tmp14 = (INT32) wsptr[4];
z1 = MULTIPLY(tmp13 + tmp14, FIX(0.790569415)); /* (c2+c4)/2 */
z2 = MULTIPLY(tmp13 - tmp14, FIX(0.353553391)); /* (c2-c4)/2 */
@@ -4748,13 +4837,15 @@
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
int ctr;
int workspace[4*8]; /* buffers data between passes */
SHIFT_TEMPS
- /* Pass 1: process columns from input, store into work array. */
- /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
+ /* Pass 1: process columns from input, store into work array.
+ * Note results are scaled up by sqrt(8) compared to a true IDCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 8-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 4; ctr > 0; ctr--) {
@@ -4787,19 +4878,13 @@
quantptr++;
wsptr++;
continue;
}
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
-
- z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
- z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
-
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865);
- tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065);
+ /* Even part: reverse the even part of the forward DCT.
+ * The rotator is c(-6).
+ */
z2 = DEQUANTIZE(inptr[DCTSIZE*0], quantptr[DCTSIZE*0]);
z3 = DEQUANTIZE(inptr[DCTSIZE*4], quantptr[DCTSIZE*4]);
z2 <<= CONST_BITS;
z3 <<= CONST_BITS;
@@ -4807,10 +4892,17 @@
z2 += ONE << (CONST_BITS-PASS1_BITS-1);
tmp0 = z2 + z3;
tmp1 = z2 - z3;
+ z2 = DEQUANTIZE(inptr[DCTSIZE*2], quantptr[DCTSIZE*2]);
+ z3 = DEQUANTIZE(inptr[DCTSIZE*6], quantptr[DCTSIZE*6]);
+
+ z1 = MULTIPLY(z2 + z3, FIX_0_541196100); /* c6 */
+ tmp2 = z1 + MULTIPLY(z2, FIX_0_765366865); /* c2-c6 */
+ tmp3 = z1 - MULTIPLY(z3, FIX_1_847759065); /* c2+c6 */
+
tmp10 = tmp0 + tmp2;
tmp13 = tmp0 - tmp2;
tmp11 = tmp1 + tmp3;
tmp12 = tmp1 - tmp3;
@@ -4824,25 +4916,25 @@
tmp3 = DEQUANTIZE(inptr[DCTSIZE*1], quantptr[DCTSIZE*1]);
z2 = tmp0 + tmp2;
z3 = tmp1 + tmp3;
- z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* sqrt(2) * c3 */
- z2 = MULTIPLY(z2, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */
- z3 = MULTIPLY(z3, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */
+ z1 = MULTIPLY(z2 + z3, FIX_1_175875602); /* c3 */
+ z2 = MULTIPLY(z2, - FIX_1_961570560); /* -c3-c5 */
+ z3 = MULTIPLY(z3, - FIX_0_390180644); /* -c3+c5 */
z2 += z1;
z3 += z1;
- z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* c1+c3-c5-c7 */
tmp0 += z1 + z2;
tmp3 += z1 + z3;
- z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* c1+c3+c5-c7 */
tmp1 += z1 + z3;
tmp2 += z1 + z2;
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
@@ -4859,20 +4951,24 @@
quantptr++;
wsptr++;
}
/* Pass 2: process 8 rows from work array, store into output array.
- * 4-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ * 4-point IDCT kernel,
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 8; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp2 = (INT32) wsptr[2];
tmp10 = (tmp0 + tmp2) << CONST_BITS;
tmp12 = (tmp0 - tmp2) << CONST_BITS;
@@ -4930,10 +5026,11 @@
SHIFT_TEMPS
/* Pass 1: process columns from input, store into work array.
* 6-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 3; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -4972,18 +5069,21 @@
}
/* Pass 2: process 6 rows from work array, store into output array.
* 3-point IDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
*/
+
wsptr = workspace;
for (ctr = 0; ctr < 6; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp0 = (INT32) wsptr[0] + (ONE << (PASS1_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 = (INT32) wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (PASS1_BITS+3)) +
+ (ONE << (PASS1_BITS+2)));
tmp0 <<= CONST_BITS;
tmp2 = (INT32) wsptr[2];
tmp12 = MULTIPLY(tmp2, FIX(0.707106781)); /* c2 */
tmp10 = tmp0 + tmp12;
tmp2 = tmp0 - tmp12 - tmp12;
@@ -5035,10 +5135,11 @@
/* Pass 1: process columns from input, store into work array.
* 4-point IDCT kernel,
* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point IDCT].
*/
+
inptr = coef_block;
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
wsptr = workspace;
for (ctr = 0; ctr < 2; ctr++, inptr++, quantptr++, wsptr++) {
/* Even part */
@@ -5073,12 +5174,14 @@
for (ctr = 0; ctr < 4; ctr++) {
outptr = output_buf[ctr] + output_col;
/* Even part */
- /* Add fudge factor here for final descale. */
- tmp10 = wsptr[0] + (ONE << (CONST_BITS+2));
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp10 = wsptr[0] +
+ ((((INT32) RANGE_CENTER) << (CONST_BITS+3)) +
+ (ONE << (CONST_BITS+2)));
/* Odd part */
tmp0 = wsptr[1];
@@ -5104,34 +5207,34 @@
GLOBAL(void)
jpeg_idct_1x2 (j_decompress_ptr cinfo, jpeg_component_info * compptr,
JCOEFPTR coef_block,
JSAMPARRAY output_buf, JDIMENSION output_col)
{
- INT32 tmp0, tmp10;
+ DCTELEM tmp0, tmp1;
ISLOW_MULT_TYPE * quantptr;
JSAMPLE *range_limit = IDCT_range_limit(cinfo);
- SHIFT_TEMPS
+ ISHIFT_TEMPS
/* Process 1 column from input, store into output array. */
quantptr = (ISLOW_MULT_TYPE *) compptr->dct_table;
/* Even part */
- tmp10 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]);
- /* Add fudge factor here for final descale. */
- tmp10 += ONE << 2;
+ tmp0 = DEQUANTIZE(coef_block[DCTSIZE*0], quantptr[DCTSIZE*0]);
+ /* Add range center and fudge factor for final descale and range-limit. */
+ tmp0 += (((DCTELEM) RANGE_CENTER) << 3) + (1 << 2);
/* Odd part */
- tmp0 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]);
+ tmp1 = DEQUANTIZE(coef_block[DCTSIZE*1], quantptr[DCTSIZE*1]);
/* Final output stage */
- output_buf[0][output_col] = range_limit[(int) RIGHT_SHIFT(tmp10 + tmp0, 3)
- & RANGE_MASK];
- output_buf[1][output_col] = range_limit[(int) RIGHT_SHIFT(tmp10 - tmp0, 3)
- & RANGE_MASK];
+ output_buf[0][output_col] =
+ range_limit[(int) IRIGHT_SHIFT(tmp0 + tmp1, 3) & RANGE_MASK];
+ output_buf[1][output_col] =
+ range_limit[(int) IRIGHT_SHIFT(tmp0 - tmp1, 3) & RANGE_MASK];
}
#endif /* IDCT_SCALING_SUPPORTED */
#endif /* DCT_ISLOW_SUPPORTED */
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