diff options
Diffstat (limited to 'plugins/AdvaImg/src/LibJPEG/jfdctint.c')
| -rw-r--r-- | plugins/AdvaImg/src/LibJPEG/jfdctint.c | 622 |
1 files changed, 340 insertions, 282 deletions
diff --git a/plugins/AdvaImg/src/LibJPEG/jfdctint.c b/plugins/AdvaImg/src/LibJPEG/jfdctint.c index 529eaf8670..4dd7cb9e6c 100644 --- a/plugins/AdvaImg/src/LibJPEG/jfdctint.c +++ b/plugins/AdvaImg/src/LibJPEG/jfdctint.c @@ -2,7 +2,7 @@ * jfdctint.c
*
* Copyright (C) 1991-1996, Thomas G. Lane.
- * Modification developed 2003-2009 by Guido Vollbeding.
+ * Modification developed 2003-2013 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.
*
@@ -165,16 +165,18 @@ jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * cK represents sqrt(2) * cos(K*pi/16).
+ */
dataptr = data;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
@@ -196,47 +198,49 @@ jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-1);
- dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
- CONST_BITS-PASS1_BITS);
- dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
- CONST_BITS-PASS1_BITS);
+
+ dataptr[2] = (DCTELEM)
+ RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS-PASS1_BITS);
+ dataptr[6] = (DCTELEM)
+ RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS-PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-1);
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
-
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[1] = (DCTELEM)
- RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
- dataptr[3] = (DCTELEM)
- RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
- dataptr[5] = (DCTELEM)
- RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
- dataptr[7] = (DCTELEM)
- RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[1] = (DCTELEM) RIGHT_SHIFT(tmp0, CONST_BITS-PASS1_BITS);
+ dataptr[3] = (DCTELEM) RIGHT_SHIFT(tmp1, CONST_BITS-PASS1_BITS);
+ dataptr[5] = (DCTELEM) RIGHT_SHIFT(tmp2, CONST_BITS-PASS1_BITS);
+ dataptr[7] = (DCTELEM) RIGHT_SHIFT(tmp3, CONST_BITS-PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
@@ -244,12 +248,13 @@ jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
+ * cK represents sqrt(2) * cos(K*pi/16).
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
@@ -271,47 +276,49 @@ jpeg_fdct_islow (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
+
dataptr[DCTSIZE*2] = (DCTELEM)
- RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
+ RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
- RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
+ RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS+PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
-
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[DCTSIZE*1] = (DCTELEM)
- RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*3] = (DCTELEM)
- RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*5] = (DCTELEM)
- RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*7] = (DCTELEM)
- RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[DCTSIZE*1] = (DCTELEM) RIGHT_SHIFT(tmp0, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*3] = (DCTELEM) RIGHT_SHIFT(tmp1, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*5] = (DCTELEM) RIGHT_SHIFT(tmp2, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*7] = (DCTELEM) RIGHT_SHIFT(tmp3, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
@@ -338,10 +345,11 @@ jpeg_fdct_7x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* cK represents sqrt(2) * cos(K*pi/14). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * cK represents sqrt(2) * cos(K*pi/14).
+ */
dataptr = data;
for (ctr = 0; ctr < 7; ctr++) {
@@ -472,10 +480,11 @@ jpeg_fdct_6x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* cK represents sqrt(2) * cos(K*pi/12). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * cK represents sqrt(2) * cos(K*pi/12).
+ */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
@@ -585,12 +594,13 @@ jpeg_fdct_5x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* cK represents sqrt(2) * cos(K*pi/10). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * cK represents sqrt(2) * cos(K*pi/10).
+ */
dataptr = data;
for (ctr = 0; ctr < 5; ctr++) {
@@ -695,11 +705,12 @@ jpeg_fdct_4x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We must also scale the output by (8/4)**2 = 2**2, which we add here. */
- /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We must also scale the output by (8/4)**2 = 2**2, which we add here.
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
+ */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
@@ -737,6 +748,7 @@ jpeg_fdct_4x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
*/
dataptr = data;
@@ -787,12 +799,13 @@ jpeg_fdct_3x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We scale the results further by 2**2 as part of output adaption */
- /* scaling for different DCT size. */
- /* cK represents sqrt(2) * cos(K*pi/6). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We scale the results further by 2**2 as part of output adaption
+ * scaling for different DCT size.
+ * cK represents sqrt(2) * cos(K*pi/6).
+ */
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
@@ -869,8 +882,9 @@ jpeg_fdct_2x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ */
/* Row 0 */
elemptr = sample_data[0] + start_col;
@@ -935,11 +949,12 @@ jpeg_fdct_9x9 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* we scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* cK represents sqrt(2) * cos(K*pi/18). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * we scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * cK represents sqrt(2) * cos(K*pi/18).
+ */
dataptr = data;
ctr = 0;
@@ -1084,11 +1099,12 @@ jpeg_fdct_10x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* we scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* cK represents sqrt(2) * cos(K*pi/20). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * we scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * cK represents sqrt(2) * cos(K*pi/20).
+ */
dataptr = data;
ctr = 0;
@@ -1248,11 +1264,12 @@ jpeg_fdct_11x11 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* we scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* cK represents sqrt(2) * cos(K*pi/22). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * we scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * cK represents sqrt(2) * cos(K*pi/22).
+ */
dataptr = data;
ctr = 0;
@@ -1430,9 +1447,10 @@ jpeg_fdct_12x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
- /* cK represents sqrt(2) * cos(K*pi/24). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ * cK represents sqrt(2) * cos(K*pi/24).
+ */
dataptr = data;
ctr = 0;
@@ -1596,9 +1614,10 @@ jpeg_fdct_13x13 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
- /* cK represents sqrt(2) * cos(K*pi/26). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ * cK represents sqrt(2) * cos(K*pi/26).
+ */
dataptr = data;
ctr = 0;
@@ -1794,9 +1813,10 @@ jpeg_fdct_14x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
- /* cK represents sqrt(2) * cos(K*pi/28). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ * cK represents sqrt(2) * cos(K*pi/28).
+ */
dataptr = data;
ctr = 0;
@@ -1995,9 +2015,10 @@ jpeg_fdct_15x15 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
- /* cK represents sqrt(2) * cos(K*pi/30). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ * cK represents sqrt(2) * cos(K*pi/30).
+ */
dataptr = data;
ctr = 0;
@@ -2173,10 +2194,11 @@ jpeg_fdct_16x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* cK represents sqrt(2) * cos(K*pi/32). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * cK represents sqrt(2) * cos(K*pi/32).
+ */
dataptr = data;
ctr = 0;
@@ -2275,6 +2297,7 @@ jpeg_fdct_16x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) * We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by (8/16)**2 = 1/2**2.
+ * cK represents sqrt(2) * cos(K*pi/32).
*/
dataptr = data;
@@ -2380,10 +2403,11 @@ jpeg_fdct_16x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 16-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/32).
+ */
dataptr = data;
ctr = 0;
@@ -2475,12 +2499,13 @@ jpeg_fdct_16x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) * We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
* We must also scale the output by 8/16 = 1/2.
+ * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
*/
dataptr = data;
for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
@@ -2501,43 +2526,43 @@ jpeg_fdct_16x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS+1);
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS+1);
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
- dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
- CONST_BITS+PASS1_BITS+1);
- dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
- CONST_BITS+PASS1_BITS+1);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
+ dataptr[DCTSIZE*2] = (DCTELEM)
+ DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS+PASS1_BITS+1);
+ dataptr[DCTSIZE*6] = (DCTELEM)
+ DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS+PASS1_BITS+1);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
-
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12,
- CONST_BITS+PASS1_BITS+1);
- dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13,
- CONST_BITS+PASS1_BITS+1);
- dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12,
- CONST_BITS+PASS1_BITS+1);
- dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13,
- CONST_BITS+PASS1_BITS+1);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp0, CONST_BITS+PASS1_BITS+1);
+ dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp1, CONST_BITS+PASS1_BITS+1);
+ dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp2, CONST_BITS+PASS1_BITS+1);
+ dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp3, CONST_BITS+PASS1_BITS+1);
dataptr++; /* advance pointer to next column */
}
@@ -2564,10 +2589,11 @@ jpeg_fdct_14x7 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Zero bottom row of output coefficient block. */
MEMZERO(&data[DCTSIZE*7], SIZEOF(DCTELEM) * DCTSIZE);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 14-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/28).
+ */
dataptr = data;
for (ctr = 0; ctr < 7; ctr++) {
@@ -2727,10 +2753,11 @@ jpeg_fdct_12x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Zero 2 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*6], SIZEOF(DCTELEM) * DCTSIZE * 2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 12-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/24).
+ */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
@@ -2866,10 +2893,11 @@ jpeg_fdct_10x5 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Zero 3 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*5], SIZEOF(DCTELEM) * DCTSIZE * 3);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 10-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/20).
+ */
dataptr = data;
for (ctr = 0; ctr < 5; ctr++) {
@@ -2999,17 +3027,19 @@ jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Zero 4 bottom rows of output coefficient block. */
MEMZERO(&data[DCTSIZE*4], SIZEOF(DCTELEM) * DCTSIZE * 4);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We must also scale the output by 8/4 = 2, which we add here. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We must also scale the output by 8/4 = 2, which we add here.
+ * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
@@ -3032,47 +3062,49 @@ jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << (PASS1_BITS+1));
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << (PASS1_BITS+1));
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-2);
- dataptr[2] = (DCTELEM) RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865),
- CONST_BITS-PASS1_BITS-1);
- dataptr[6] = (DCTELEM) RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065),
- CONST_BITS-PASS1_BITS-1);
+
+ dataptr[2] = (DCTELEM)
+ RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS-PASS1_BITS-1);
+ dataptr[6] = (DCTELEM)
+ RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS-PASS1_BITS-1);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS-PASS1_BITS-2);
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
-
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[1] = (DCTELEM)
- RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS-1);
- dataptr[3] = (DCTELEM)
- RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS-1);
- dataptr[5] = (DCTELEM)
- RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS-1);
- dataptr[7] = (DCTELEM)
- RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS-1);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[1] = (DCTELEM) RIGHT_SHIFT(tmp0, CONST_BITS-PASS1_BITS-1);
+ dataptr[3] = (DCTELEM) RIGHT_SHIFT(tmp1, CONST_BITS-PASS1_BITS-1);
+ dataptr[5] = (DCTELEM) RIGHT_SHIFT(tmp2, CONST_BITS-PASS1_BITS-1);
+ dataptr[7] = (DCTELEM) RIGHT_SHIFT(tmp3, CONST_BITS-PASS1_BITS-1);
dataptr += DCTSIZE; /* advance pointer to next row */
}
@@ -3080,7 +3112,8 @@ jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
- * 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ * 4-point FDCT kernel,
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
*/
dataptr = data;
@@ -3099,7 +3132,7 @@ jpeg_fdct_8x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Odd part */
- tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
+ tmp0 = MULTIPLY(tmp10 + tmp11, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
tmp0 += ONE << (CONST_BITS+PASS1_BITS-1);
@@ -3134,12 +3167,13 @@ jpeg_fdct_6x3 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
+ */
dataptr = data;
for (ctr = 0; ctr < 3; ctr++) {
@@ -3234,12 +3268,13 @@ jpeg_fdct_4x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We must also scale the output by (8/4)*(8/2) = 2**3, which we add here. */
- /* 4-point FDCT kernel, */
- /* cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT]. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We must also scale the output by (8/4)*(8/2) = 2**3, which we add here.
+ * 4-point FDCT kernel,
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
+ */
dataptr = data;
for (ctr = 0; ctr < 2; ctr++) {
@@ -3323,10 +3358,12 @@ jpeg_fdct_2x1 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) */
/* Even part */
+
/* Apply unsigned->signed conversion */
data[0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
/* Odd part */
+
data[1] = (DCTELEM) ((tmp0 - tmp1) << 5);
}
@@ -3350,9 +3387,11 @@ jpeg_fdct_8x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) int ctr;
SHIFT_TEMPS
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
+ */
dataptr = data;
ctr = 0;
@@ -3360,7 +3399,7 @@ jpeg_fdct_8x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) elemptr = sample_data[ctr] + start_col;
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = GETJSAMPLE(elemptr[0]) + GETJSAMPLE(elemptr[7]);
@@ -3382,39 +3421,43 @@ jpeg_fdct_8x16 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) dataptr[0] = (DCTELEM) ((tmp10 + tmp11 - 8 * CENTERJSAMPLE) << PASS1_BITS);
dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS);
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
- dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865),
- CONST_BITS-PASS1_BITS);
- dataptr[6] = (DCTELEM) DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065),
- CONST_BITS-PASS1_BITS);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
+ dataptr[2] = (DCTELEM)
+ DESCALE(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS-PASS1_BITS);
+ dataptr[6] = (DCTELEM)
+ DESCALE(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS-PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
-
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[1] = (DCTELEM) DESCALE(tmp0 + tmp10 + tmp12, CONST_BITS-PASS1_BITS);
- dataptr[3] = (DCTELEM) DESCALE(tmp1 + tmp11 + tmp13, CONST_BITS-PASS1_BITS);
- dataptr[5] = (DCTELEM) DESCALE(tmp2 + tmp11 + tmp12, CONST_BITS-PASS1_BITS);
- dataptr[7] = (DCTELEM) DESCALE(tmp3 + tmp10 + tmp13, CONST_BITS-PASS1_BITS);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[1] = (DCTELEM) DESCALE(tmp0, CONST_BITS-PASS1_BITS);
+ dataptr[3] = (DCTELEM) DESCALE(tmp1, CONST_BITS-PASS1_BITS);
+ dataptr[5] = (DCTELEM) DESCALE(tmp2, CONST_BITS-PASS1_BITS);
+ dataptr[7] = (DCTELEM) DESCALE(tmp3, CONST_BITS-PASS1_BITS);
ctr++;
@@ -3541,10 +3584,11 @@ jpeg_fdct_7x14 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 7-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/14).
+ */
dataptr = data;
ctr = 0;
@@ -3721,10 +3765,11 @@ jpeg_fdct_6x12 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 6-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/12).
+ */
dataptr = data;
ctr = 0;
@@ -3870,10 +3915,11 @@ jpeg_fdct_5x10 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * 5-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/10).
+ */
dataptr = data;
ctr = 0;
@@ -4015,11 +4061,13 @@ jpeg_fdct_4x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We must also scale the output by 8/4 = 2, which we add here. */
- /* 4-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We must also scale the output by 8/4 = 2, which we add here.
+ * 4-point FDCT kernel,
+ * cK represents sqrt(2) * cos(K*pi/16) [refers to 8-point FDCT].
+ */
dataptr = data;
for (ctr = 0; ctr < DCTSIZE; ctr++) {
@@ -4057,12 +4105,13 @@ jpeg_fdct_4x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
* by an overall factor of 8.
+ * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
*/
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
/* Even part per LL&M figure 1 --- note that published figure is faulty;
- * rotator "sqrt(2)*c1" should be "sqrt(2)*c6".
+ * rotator "c1" should be "c6".
*/
tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*7];
@@ -4084,47 +4133,49 @@ jpeg_fdct_4x8 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) dataptr[DCTSIZE*0] = (DCTELEM) RIGHT_SHIFT(tmp10 + tmp11, PASS1_BITS);
dataptr[DCTSIZE*4] = (DCTELEM) RIGHT_SHIFT(tmp10 - tmp11, PASS1_BITS);
- z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); /* c6 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
+
dataptr[DCTSIZE*2] = (DCTELEM)
- RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), CONST_BITS+PASS1_BITS);
+ RIGHT_SHIFT(z1 + MULTIPLY(tmp12, FIX_0_765366865), /* c2-c6 */
+ CONST_BITS+PASS1_BITS);
dataptr[DCTSIZE*6] = (DCTELEM)
- RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), CONST_BITS+PASS1_BITS);
+ RIGHT_SHIFT(z1 - MULTIPLY(tmp13, FIX_1_847759065), /* c2+c6 */
+ CONST_BITS+PASS1_BITS);
/* Odd part per figure 8 --- note paper omits factor of sqrt(2).
- * 8-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/16).
* i0..i3 in the paper are tmp0..tmp3 here.
*/
- tmp10 = tmp0 + tmp3;
- tmp11 = tmp1 + tmp2;
tmp12 = tmp0 + tmp2;
tmp13 = tmp1 + tmp3;
- z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_1_175875602); /* c3 */
/* Add fudge factor here for final descale. */
z1 += ONE << (CONST_BITS+PASS1_BITS-1);
- tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
- tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
- tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
- tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
- tmp10 = MULTIPLY(tmp10, - FIX_0_899976223); /* c7-c3 */
- tmp11 = MULTIPLY(tmp11, - FIX_2_562915447); /* -c1-c3 */
- tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* c5-c3 */
- tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
-
+ tmp12 = MULTIPLY(tmp12, - FIX_0_390180644); /* -c3+c5 */
+ tmp13 = MULTIPLY(tmp13, - FIX_1_961570560); /* -c3-c5 */
tmp12 += z1;
tmp13 += z1;
- dataptr[DCTSIZE*1] = (DCTELEM)
- RIGHT_SHIFT(tmp0 + tmp10 + tmp12, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*3] = (DCTELEM)
- RIGHT_SHIFT(tmp1 + tmp11 + tmp13, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*5] = (DCTELEM)
- RIGHT_SHIFT(tmp2 + tmp11 + tmp12, CONST_BITS+PASS1_BITS);
- dataptr[DCTSIZE*7] = (DCTELEM)
- RIGHT_SHIFT(tmp3 + tmp10 + tmp13, CONST_BITS+PASS1_BITS);
+ z1 = MULTIPLY(tmp0 + tmp3, - FIX_0_899976223); /* -c3+c7 */
+ tmp0 = MULTIPLY(tmp0, FIX_1_501321110); /* c1+c3-c5-c7 */
+ tmp3 = MULTIPLY(tmp3, FIX_0_298631336); /* -c1+c3+c5-c7 */
+ tmp0 += z1 + tmp12;
+ tmp3 += z1 + tmp13;
+
+ z1 = MULTIPLY(tmp1 + tmp2, - FIX_2_562915447); /* -c1-c3 */
+ tmp1 = MULTIPLY(tmp1, FIX_3_072711026); /* c1+c3+c5-c7 */
+ tmp2 = MULTIPLY(tmp2, FIX_2_053119869); /* c1+c3-c5+c7 */
+ tmp1 += z1 + tmp13;
+ tmp2 += z1 + tmp12;
+
+ dataptr[DCTSIZE*1] = (DCTELEM) RIGHT_SHIFT(tmp0, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*3] = (DCTELEM) RIGHT_SHIFT(tmp1, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*5] = (DCTELEM) RIGHT_SHIFT(tmp2, CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*7] = (DCTELEM) RIGHT_SHIFT(tmp3, CONST_BITS+PASS1_BITS);
dataptr++; /* advance pointer to next column */
}
@@ -4150,12 +4201,13 @@ jpeg_fdct_3x6 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- /* We scale the results further by 2 as part of output adaption */
- /* scaling for different DCT size. */
- /* 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6). */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT;
+ * furthermore, we scale the results by 2**PASS1_BITS.
+ * We scale the results further by 2 as part of output adaption
+ * scaling for different DCT size.
+ * 3-point FDCT kernel, cK represents sqrt(2) * cos(K*pi/6).
+ */
dataptr = data;
for (ctr = 0; ctr < 6; ctr++) {
@@ -4255,9 +4307,10 @@ jpeg_fdct_2x4 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true DCT. */
- /* We must also scale the output by (8/2)*(8/4) = 2**3, which we add here. */
+ /* Pass 1: process rows.
+ * Note results are scaled up by sqrt(8) compared to a true DCT.
+ * We must also scale the output by (8/2)*(8/4) = 2**3, which we add here.
+ */
dataptr = data;
for (ctr = 0; ctr < 4; ctr++) {
@@ -4329,18 +4382,23 @@ jpeg_fdct_1x2 (DCTELEM * data, JSAMPARRAY sample_data, JDIMENSION start_col) /* Pre-zero output coefficient block. */
MEMZERO(data, SIZEOF(DCTELEM) * DCTSIZE2);
- tmp0 = GETJSAMPLE(sample_data[0][start_col]);
- tmp1 = GETJSAMPLE(sample_data[1][start_col]);
+ /* Pass 1: empty. */
- /* We leave the results scaled up by an overall factor of 8.
+ /* Pass 2: process columns.
+ * We leave the results scaled up by an overall factor of 8.
* We must also scale the output by (8/1)*(8/2) = 2**5.
*/
/* Even part */
+
+ tmp0 = GETJSAMPLE(sample_data[0][start_col]);
+ tmp1 = GETJSAMPLE(sample_data[1][start_col]);
+
/* Apply unsigned->signed conversion */
data[DCTSIZE*0] = (DCTELEM) ((tmp0 + tmp1 - 2 * CENTERJSAMPLE) << 5);
/* Odd part */
+
data[DCTSIZE*1] = (DCTELEM) ((tmp0 - tmp1) << 5);
}
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