* scaled fixed-point arithmetic, with a minimal number of shifts.
*/
+/**
+ * @file jfdctint.c
+ * Independent JPEG Group's slow & accurate dct.
+ */
+
#include <stdlib.h>
#include <stdio.h>
#include "common.h"
* 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 int32_t 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
#if BITS_IN_JSAMPLE == 8
#define CONST_BITS 13
-#define PASS1_BITS 4 /* set this to 2 if 16x16 multiplies are faster */
+#define PASS1_BITS 4 /* set this to 2 if 16x16 multiplies are faster */
#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
*/
#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 ((int32_t) 2446) /* FIX(0.298631336) */
+#define FIX_0_390180644 ((int32_t) 3196) /* FIX(0.390180644) */
+#define FIX_0_541196100 ((int32_t) 4433) /* FIX(0.541196100) */
+#define FIX_0_765366865 ((int32_t) 6270) /* FIX(0.765366865) */
+#define FIX_0_899976223 ((int32_t) 7373) /* FIX(0.899976223) */
+#define FIX_1_175875602 ((int32_t) 9633) /* FIX(1.175875602) */
+#define FIX_1_501321110 ((int32_t) 12299) /* FIX(1.501321110) */
+#define FIX_1_847759065 ((int32_t) 15137) /* FIX(1.847759065) */
+#define FIX_1_961570560 ((int32_t) 16069) /* FIX(1.961570560) */
+#define FIX_2_053119869 ((int32_t) 16819) /* FIX(2.053119869) */
+#define FIX_2_562915447 ((int32_t) 20995) /* FIX(2.562915447) */
+#define FIX_3_072711026 ((int32_t) 25172) /* FIX(3.072711026) */
#else
#define FIX_0_298631336 FIX(0.298631336)
#define FIX_0_390180644 FIX(0.390180644)
#endif
-/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
+/* Multiply an int32_t variable by an int32_t constant to yield an int32_t 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.
#endif
-/*
- * Perform the forward DCT on one block of samples.
- */
-
-GLOBAL(void)
-ff_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;
+static always_inline void row_fdct(DCTELEM * data){
+ int_fast32_t tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int_fast32_t tmp10, tmp11, tmp12, tmp13;
+ int_fast32_t z1, z2, z3, z4, z5;
DCTELEM *dataptr;
int ctr;
SHIFT_TEMPS
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);
-
+
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) */
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 */
}
+}
+
+/*
+ * Perform the forward DCT on one block of samples.
+ */
+
+GLOBAL(void)
+ff_jpeg_fdct_islow (DCTELEM * data)
+{
+ int_fast32_t tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int_fast32_t tmp10, tmp11, tmp12, tmp13;
+ int_fast32_t z1, z2, z3, z4, z5;
+ DCTELEM *dataptr;
+ int ctr;
+ SHIFT_TEMPS
+
+ row_fdct(data);
/* Pass 2: process columns.
* We remove the PASS1_BITS scaling, but leave the results scaled up
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) */
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 */
+ }
+}
+
+/*
+ * The secret of DCT2-4-8 is really simple -- you do the usual 1-DCT
+ * on the rows and then, instead of doing even and odd, part on the colums
+ * you do even part two times.
+ */
+GLOBAL(void)
+ff_fdct248_islow (DCTELEM * data)
+{
+ int_fast32_t tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
+ int_fast32_t tmp10, tmp11, tmp12, tmp13;
+ int_fast32_t z1;
+ DCTELEM *dataptr;
+ int ctr;
+ SHIFT_TEMPS
+
+ row_fdct(data);
+
+ /* Pass 2: process columns.
+ * We remove the PASS1_BITS scaling, but leave the results scaled up
+ * by an overall factor of 8.
+ */
+
+ dataptr = data;
+ for (ctr = DCTSIZE-1; ctr >= 0; ctr--) {
+ tmp0 = dataptr[DCTSIZE*0] + dataptr[DCTSIZE*1];
+ tmp1 = dataptr[DCTSIZE*2] + dataptr[DCTSIZE*3];
+ tmp2 = dataptr[DCTSIZE*4] + dataptr[DCTSIZE*5];
+ tmp3 = dataptr[DCTSIZE*6] + dataptr[DCTSIZE*7];
+ tmp4 = dataptr[DCTSIZE*0] - dataptr[DCTSIZE*1];
+ tmp5 = dataptr[DCTSIZE*2] - dataptr[DCTSIZE*3];
+ tmp6 = dataptr[DCTSIZE*4] - dataptr[DCTSIZE*5];
+ tmp7 = dataptr[DCTSIZE*6] - dataptr[DCTSIZE*7];
+
+ tmp10 = tmp0 + tmp3;
+ tmp11 = tmp1 + tmp2;
+ tmp12 = tmp1 - tmp2;
+ tmp13 = tmp0 - tmp3;
+
+ 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);
+ dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
+ CONST_BITS+PASS1_BITS);
+
+ tmp10 = tmp4 + tmp7;
+ tmp11 = tmp5 + tmp6;
+ tmp12 = tmp5 - tmp6;
+ tmp13 = tmp4 - tmp7;
+
+ dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp10 + tmp11, PASS1_BITS);
+ dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp10 - tmp11, PASS1_BITS);
+
+ z1 = MULTIPLY(tmp12 + tmp13, FIX_0_541196100);
+ dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp13, FIX_0_765366865),
+ CONST_BITS+PASS1_BITS);
+ dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(z1 + MULTIPLY(tmp12, - FIX_1_847759065),
+ CONST_BITS+PASS1_BITS);
+
+ dataptr++; /* advance pointer to next column */
}
}
projects / ffmpeg / blobdiff