Index: jfdctint.c |
diff --git a/jfdctint.c b/jfdctint.c |
index 0a78b64aee8ffd7fc6c3469495ec577a59d44ed1..73e0b59032c90a1da7e2b8f9bfc0fd9593019587 100644 |
--- a/jfdctint.c |
+++ b/jfdctint.c |
@@ -1,9 +1,12 @@ |
/* |
* jfdctint.c |
* |
+ * This file was part of the Independent JPEG Group's software. |
* Copyright (C) 1991-1996, Thomas G. Lane. |
- * This file is part of the Independent JPEG Group's software. |
- * For conditions of distribution and use, see the accompanying README file. |
+ * libjpeg-turbo Modifications: |
+ * Copyright (C) 2015, D. R. Commander |
+ * For conditions of distribution and use, see the accompanying README.ijg |
+ * file. |
* |
* This file contains a slow-but-accurate integer implementation of the |
* forward DCT (Discrete Cosine Transform). |
@@ -26,7 +29,7 @@ |
#define JPEG_INTERNALS |
#include "jinclude.h" |
#include "jpeglib.h" |
-#include "jdct.h" /* Private declarations for DCT subsystem */ |
+#include "jdct.h" /* Private declarations for DCT subsystem */ |
#ifdef DCT_ISLOW_SUPPORTED |
@@ -67,7 +70,7 @@ |
* they are represented to better-than-integral precision. These outputs |
* require BITS_IN_JSAMPLE + PASS1_BITS + 3 bits; this fits in a 16-bit word |
* with the recommended scaling. (For 12-bit sample data, the intermediate |
- * array is INT32 anyway.) |
+ * array is JLONG anyway.) |
* |
* To avoid overflow of the 32-bit intermediate results in pass 2, we must |
* have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis |
@@ -79,7 +82,7 @@ |
#define PASS1_BITS 2 |
#else |
#define CONST_BITS 13 |
-#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ |
+#define PASS1_BITS 1 /* lose a little precision to avoid overflow */ |
#endif |
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus |
@@ -90,18 +93,18 @@ |
*/ |
#if CONST_BITS == 13 |
-#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */ |
-#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */ |
-#define FIX_0_541196100 ((INT32) 4433) /* FIX(0.541196100) */ |
-#define FIX_0_765366865 ((INT32) 6270) /* FIX(0.765366865) */ |
-#define FIX_0_899976223 ((INT32) 7373) /* FIX(0.899976223) */ |
-#define FIX_1_175875602 ((INT32) 9633) /* FIX(1.175875602) */ |
-#define FIX_1_501321110 ((INT32) 12299) /* FIX(1.501321110) */ |
-#define FIX_1_847759065 ((INT32) 15137) /* FIX(1.847759065) */ |
-#define FIX_1_961570560 ((INT32) 16069) /* FIX(1.961570560) */ |
-#define FIX_2_053119869 ((INT32) 16819) /* FIX(2.053119869) */ |
-#define FIX_2_562915447 ((INT32) 20995) /* FIX(2.562915447) */ |
-#define FIX_3_072711026 ((INT32) 25172) /* FIX(3.072711026) */ |
+#define FIX_0_298631336 ((JLONG) 2446) /* FIX(0.298631336) */ |
+#define FIX_0_390180644 ((JLONG) 3196) /* FIX(0.390180644) */ |
+#define FIX_0_541196100 ((JLONG) 4433) /* FIX(0.541196100) */ |
+#define FIX_0_765366865 ((JLONG) 6270) /* FIX(0.765366865) */ |
+#define FIX_0_899976223 ((JLONG) 7373) /* FIX(0.899976223) */ |
+#define FIX_1_175875602 ((JLONG) 9633) /* FIX(1.175875602) */ |
+#define FIX_1_501321110 ((JLONG) 12299) /* FIX(1.501321110) */ |
+#define FIX_1_847759065 ((JLONG) 15137) /* FIX(1.847759065) */ |
+#define FIX_1_961570560 ((JLONG) 16069) /* FIX(1.961570560) */ |
+#define FIX_2_053119869 ((JLONG) 16819) /* FIX(2.053119869) */ |
+#define FIX_2_562915447 ((JLONG) 20995) /* FIX(2.562915447) */ |
+#define FIX_3_072711026 ((JLONG) 25172) /* FIX(3.072711026) */ |
#else |
#define FIX_0_298631336 FIX(0.298631336) |
#define FIX_0_390180644 FIX(0.390180644) |
@@ -118,7 +121,7 @@ |
#endif |
-/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result. |
+/* Multiply an JLONG variable by an JLONG constant to yield an JLONG result. |
* For 8-bit samples with the recommended scaling, all the variable |
* and constant values involved are no more than 16 bits wide, so a |
* 16x16->32 bit multiply can be used instead of a full 32x32 multiply. |
@@ -137,11 +140,11 @@ |
*/ |
GLOBAL(void) |
-jpeg_fdct_islow (DCTELEM * data) |
+jpeg_fdct_islow (DCTELEM *data) |
{ |
- INT32 tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
- INT32 tmp10, tmp11, tmp12, tmp13; |
- INT32 z1, z2, z3, z4, z5; |
+ JLONG tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7; |
+ JLONG tmp10, tmp11, tmp12, tmp13; |
+ JLONG z1, z2, z3, z4, z5; |
DCTELEM *dataptr; |
int ctr; |
SHIFT_TEMPS |
@@ -160,36 +163,36 @@ jpeg_fdct_islow (DCTELEM * data) |
tmp5 = dataptr[2] - dataptr[5]; |
tmp3 = dataptr[3] + dataptr[4]; |
tmp4 = dataptr[3] - dataptr[4]; |
- |
+ |
/* Even part per LL&M figure 1 --- note that published figure is faulty; |
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6". |
*/ |
- |
+ |
tmp10 = tmp0 + tmp3; |
tmp13 = tmp0 - tmp3; |
tmp11 = tmp1 + tmp2; |
tmp12 = tmp1 - tmp2; |
- |
- dataptr[0] = (DCTELEM) ((tmp10 + tmp11) << PASS1_BITS); |
- dataptr[4] = (DCTELEM) ((tmp10 - tmp11) << PASS1_BITS); |
- |
+ |
+ dataptr[0] = (DCTELEM) LEFT_SHIFT(tmp10 + tmp11, PASS1_BITS); |
+ dataptr[4] = (DCTELEM) LEFT_SHIFT(tmp10 - tmp11, PASS1_BITS); |
+ |
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); |
dataptr[2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865), |
- CONST_BITS-PASS1_BITS); |
+ CONST_BITS-PASS1_BITS); |
dataptr[6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065), |
- CONST_BITS-PASS1_BITS); |
- |
+ CONST_BITS-PASS1_BITS); |
+ |
/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
* cK represents cos(K*pi/16). |
* i0..i3 in the paper are tmp4..tmp7 here. |
*/ |
- |
+ |
z1 = tmp4 + tmp7; |
z2 = tmp5 + tmp6; |
z3 = tmp4 + tmp6; |
z4 = tmp5 + tmp7; |
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */ |
- |
+ |
tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ |
tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ |
tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ |
@@ -198,16 +201,16 @@ jpeg_fdct_islow (DCTELEM * data) |
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ |
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ |
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ |
- |
+ |
z3 += z5; |
z4 += z5; |
- |
+ |
dataptr[7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, CONST_BITS-PASS1_BITS); |
dataptr[5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, CONST_BITS-PASS1_BITS); |
dataptr[3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, CONST_BITS-PASS1_BITS); |
dataptr[1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, CONST_BITS-PASS1_BITS); |
- |
- dataptr += DCTSIZE; /* advance pointer to next row */ |
+ |
+ dataptr += DCTSIZE; /* advance pointer to next row */ |
} |
/* Pass 2: process columns. |
@@ -225,36 +228,36 @@ jpeg_fdct_islow (DCTELEM * data) |
tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*5]; |
tmp3 = dataptr[DCTSIZE*3] + dataptr[DCTSIZE*4]; |
tmp4 = dataptr[DCTSIZE*3] - dataptr[DCTSIZE*4]; |
- |
+ |
/* Even part per LL&M figure 1 --- note that published figure is faulty; |
* rotator "sqrt(2)*c1" should be "sqrt(2)*c6". |
*/ |
- |
+ |
tmp10 = tmp0 + tmp3; |
tmp13 = tmp0 - tmp3; |
tmp11 = tmp1 + tmp2; |
tmp12 = tmp1 - tmp2; |
- |
+ |
dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS); |
dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS); |
- |
+ |
z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100); |
dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865), |
- CONST_BITS+PASS1_BITS); |
+ CONST_BITS+PASS1_BITS); |
dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065), |
- CONST_BITS+PASS1_BITS); |
- |
+ CONST_BITS+PASS1_BITS); |
+ |
/* Odd part per figure 8 --- note paper omits factor of sqrt(2). |
* cK represents cos(K*pi/16). |
* i0..i3 in the paper are tmp4..tmp7 here. |
*/ |
- |
+ |
z1 = tmp4 + tmp7; |
z2 = tmp5 + tmp6; |
z3 = tmp4 + tmp6; |
z4 = tmp5 + tmp7; |
z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */ |
- |
+ |
tmp4 = MULTIPLY(tmp4, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */ |
tmp5 = MULTIPLY(tmp5, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */ |
tmp6 = MULTIPLY(tmp6, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */ |
@@ -263,20 +266,20 @@ jpeg_fdct_islow (DCTELEM * data) |
z2 = MULTIPLY(z2, - FIX_2_562915447); /* sqrt(2) * (-c1-c3) */ |
z3 = MULTIPLY(z3, - FIX_1_961570560); /* sqrt(2) * (-c3-c5) */ |
z4 = MULTIPLY(z4, - FIX_0_390180644); /* sqrt(2) * (c5-c3) */ |
- |
+ |
z3 += z5; |
z4 += z5; |
- |
+ |
dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp4 + z1 + z3, |
- CONST_BITS+PASS1_BITS); |
+ CONST_BITS+PASS1_BITS); |
dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp5 + z2 + z4, |
- CONST_BITS+PASS1_BITS); |
+ CONST_BITS+PASS1_BITS); |
dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp6 + z2 + z3, |
- CONST_BITS+PASS1_BITS); |
+ CONST_BITS+PASS1_BITS); |
dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp7 + z1 + z4, |
- CONST_BITS+PASS1_BITS); |
- |
- dataptr++; /* advance pointer to next column */ |
+ CONST_BITS+PASS1_BITS); |
+ |
+ dataptr++; /* advance pointer to next column */ |
} |
} |