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-rw-r--r--gst-libs/gst/idct/intidct.c205
1 files changed, 95 insertions, 110 deletions
diff --git a/gst-libs/gst/idct/intidct.c b/gst-libs/gst/idct/intidct.c
index e08e6adb..42f0ac84 100644
--- a/gst-libs/gst/idct/intidct.c
+++ b/gst-libs/gst/idct/intidct.c
@@ -51,10 +51,8 @@
*/
#if DCTSIZE != 8
- Sorry, this code only copes with 8x8 DCTs. /* deliberate syntax err */
+Sorry, this code only copes with 8 x8 DCTs. /* deliberate syntax err */
#endif
-
-
/*
* A 2-D IDCT can be done by 1-D IDCT on each row followed by 1-D IDCT
* on each column. Direct algorithms are also available, but they are
@@ -90,7 +88,6 @@
* have BITS_IN_JSAMPLE + CONST_BITS + PASS1_BITS <= 26. Error analysis
* shows that the values given below are the most effective.
*/
-
#ifdef EIGHT_BIT_SAMPLES
#define CONST_BITS 13
#define PASS1_BITS 2
@@ -98,22 +95,16 @@
#define CONST_BITS 13
#define PASS1_BITS 1 /* lose a little precision to avoid overflow */
#endif
-
#define ONE ((INT32) 1)
-
#define CONST_SCALE (ONE << CONST_BITS)
-
/* Convert a positive real constant to an integer scaled by CONST_SCALE. */
-
#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
-
/* Some C compilers fail to reduce "FIX(constant)" at compile time, thus
* causing a lot of useless floating-point operations at run time.
* To get around this we use the following pre-calculated constants.
* If you change CONST_BITS you may want to add appropriate values.
* (With a reasonable C compiler, you can just rely on the FIX() macro...)
*/
-
#if CONST_BITS == 13
#define FIX_0_298631336 ((INT32) 2446) /* FIX(0.298631336) */
#define FIX_0_390180644 ((INT32) 3196) /* FIX(0.390180644) */
@@ -141,15 +132,11 @@
#define FIX_2_562915447 FIX(2.562915447)
#define FIX_3_072711026 FIX(3.072711026)
#endif
-
-
/* Descale and correctly round an INT32 value that's scaled by N bits.
* We assume RIGHT_SHIFT rounds towards minus infinity, so adding
* the fudge factor is correct for either sign of X.
*/
-
#define DESCALE(x,n) RIGHT_SHIFT((x) + (ONE << ((n)-1)), n)
-
/* Multiply an INT32 variable by an INT32 constant to yield an INT32 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
@@ -160,7 +147,6 @@
* combination of casts.
* NB: for 12-bit samples, a full 32-bit multiplication will be needed.
*/
-
#ifdef EIGHT_BIT_SAMPLES
#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
#define MULTIPLY(var,const) (((INT16) (var)) * ((INT16) (const)))
@@ -169,17 +155,13 @@
#define MULTIPLY(var,const) (((INT16) (var)) * ((INT32) (const)))
#endif
#endif
-
#ifndef MULTIPLY /* default definition */
#define MULTIPLY(var,const) ((var) * (const))
#endif
-
-
/*
* Perform the inverse DCT on one block of coefficients.
*/
-
-void
+ void
gst_idct_int_idct (DCTBLOCK data)
{
INT32 tmp0, tmp1, tmp2, tmp3;
@@ -187,14 +169,13 @@ gst_idct_int_idct (DCTBLOCK data)
INT32 z1, z2, z3, z4, z5;
register DCTELEM *dataptr;
int rowctr;
- SHIFT_TEMPS
-
- /* Pass 1: process rows. */
- /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
- /* furthermore, we scale the results by 2**PASS1_BITS. */
- dataptr = data;
- for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
+ SHIFT_TEMPS
+ /* Pass 1: process rows. */
+ /* Note results are scaled up by sqrt(8) compared to a true IDCT; */
+ /* furthermore, we scale the results by 2**PASS1_BITS. */
+ dataptr = data;
+ for (rowctr = DCTSIZE - 1; rowctr >= 0; rowctr--) {
/* Due to quantization, we will usually find that many of the input
* coefficients are zero, especially the AC terms. We can exploit this
* by short-circuiting the IDCT calculation for any row in which all
@@ -205,10 +186,10 @@ gst_idct_int_idct (DCTBLOCK data)
*/
if ((dataptr[1] | dataptr[2] | dataptr[3] | dataptr[4] |
- dataptr[5] | dataptr[6] | dataptr[7]) == 0) {
+ dataptr[5] | dataptr[6] | dataptr[7]) == 0) {
/* AC terms all zero */
DCTELEM dcval = (DCTELEM) (dataptr[0] << PASS1_BITS);
-
+
dataptr[0] = dcval;
dataptr[1] = dcval;
dataptr[2] = dcval;
@@ -217,7 +198,7 @@ gst_idct_int_idct (DCTBLOCK data)
dataptr[5] = dcval;
dataptr[6] = dcval;
dataptr[7] = dcval;
-
+
dataptr += DCTSIZE; /* advance pointer to next row */
continue;
}
@@ -228,9 +209,9 @@ gst_idct_int_idct (DCTBLOCK data)
z2 = (INT32) dataptr[2];
z3 = (INT32) dataptr[6];
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
+ z1 = MULTIPLY (z2 + z3, FIX_0_541196100);
+ tmp2 = z1 + MULTIPLY (z3, -FIX_1_847759065);
+ tmp3 = z1 + MULTIPLY (z2, FIX_0_765366865);
tmp0 = ((INT32) dataptr[0] + (INT32) dataptr[4]) << CONST_BITS;
tmp1 = ((INT32) dataptr[0] - (INT32) dataptr[4]) << CONST_BITS;
@@ -239,7 +220,7 @@ gst_idct_int_idct (DCTBLOCK data)
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
-
+
/* Odd part per figure 8; the matrix is unitary and hence its
* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
*/
@@ -253,20 +234,20 @@ gst_idct_int_idct (DCTBLOCK data)
z2 = tmp1 + tmp2;
z3 = tmp0 + tmp2;
z4 = tmp1 + tmp3;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
- z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- 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) */
-
+ z5 = MULTIPLY (z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp0 = MULTIPLY (tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp1 = MULTIPLY (tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp2 = MULTIPLY (tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp3 = MULTIPLY (tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY (z1, -FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ 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;
-
+
tmp0 += z1 + z3;
tmp1 += z2 + z4;
tmp2 += z2 + z3;
@@ -274,14 +255,14 @@ gst_idct_int_idct (DCTBLOCK data)
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
- dataptr[0] = (DCTELEM) DESCALE(tmp10 + tmp3, CONST_BITS-PASS1_BITS);
- dataptr[7] = (DCTELEM) DESCALE(tmp10 - tmp3, CONST_BITS-PASS1_BITS);
- dataptr[1] = (DCTELEM) DESCALE(tmp11 + tmp2, CONST_BITS-PASS1_BITS);
- dataptr[6] = (DCTELEM) DESCALE(tmp11 - tmp2, CONST_BITS-PASS1_BITS);
- dataptr[2] = (DCTELEM) DESCALE(tmp12 + tmp1, CONST_BITS-PASS1_BITS);
- dataptr[5] = (DCTELEM) DESCALE(tmp12 - tmp1, CONST_BITS-PASS1_BITS);
- dataptr[3] = (DCTELEM) DESCALE(tmp13 + tmp0, CONST_BITS-PASS1_BITS);
- dataptr[4] = (DCTELEM) DESCALE(tmp13 - tmp0, CONST_BITS-PASS1_BITS);
+ dataptr[0] = (DCTELEM) DESCALE (tmp10 + tmp3, CONST_BITS - PASS1_BITS);
+ dataptr[7] = (DCTELEM) DESCALE (tmp10 - tmp3, CONST_BITS - PASS1_BITS);
+ dataptr[1] = (DCTELEM) DESCALE (tmp11 + tmp2, CONST_BITS - PASS1_BITS);
+ dataptr[6] = (DCTELEM) DESCALE (tmp11 - tmp2, CONST_BITS - PASS1_BITS);
+ dataptr[2] = (DCTELEM) DESCALE (tmp12 + tmp1, CONST_BITS - PASS1_BITS);
+ dataptr[5] = (DCTELEM) DESCALE (tmp12 - tmp1, CONST_BITS - PASS1_BITS);
+ dataptr[3] = (DCTELEM) DESCALE (tmp13 + tmp0, CONST_BITS - PASS1_BITS);
+ dataptr[4] = (DCTELEM) DESCALE (tmp13 - tmp0, CONST_BITS - PASS1_BITS);
dataptr += DCTSIZE; /* advance pointer to next row */
}
@@ -291,7 +272,7 @@ gst_idct_int_idct (DCTBLOCK data)
/* and also undo the PASS1_BITS scaling. */
dataptr = data;
- for (rowctr = DCTSIZE-1; rowctr >= 0; rowctr--) {
+ for (rowctr = DCTSIZE - 1; rowctr >= 0; rowctr--) {
/* Columns of zeroes can be exploited in the same way as we did with rows.
* However, the row calculation has created many nonzero AC terms, so the
* simplification applies less often (typically 5% to 10% of the time).
@@ -301,21 +282,21 @@ gst_idct_int_idct (DCTBLOCK data)
*/
#ifndef NO_ZERO_COLUMN_TEST
- if ((dataptr[DCTSIZE*1] | dataptr[DCTSIZE*2] | dataptr[DCTSIZE*3] |
- dataptr[DCTSIZE*4] | dataptr[DCTSIZE*5] | dataptr[DCTSIZE*6] |
- dataptr[DCTSIZE*7]) == 0) {
+ if ((dataptr[DCTSIZE * 1] | dataptr[DCTSIZE * 2] | dataptr[DCTSIZE * 3] |
+ dataptr[DCTSIZE * 4] | dataptr[DCTSIZE * 5] | dataptr[DCTSIZE * 6] |
+ dataptr[DCTSIZE * 7]) == 0) {
/* AC terms all zero */
- DCTELEM dcval = (DCTELEM) DESCALE((INT32) dataptr[0], PASS1_BITS+3);
-
- dataptr[DCTSIZE*0] = dcval;
- dataptr[DCTSIZE*1] = dcval;
- dataptr[DCTSIZE*2] = dcval;
- dataptr[DCTSIZE*3] = dcval;
- dataptr[DCTSIZE*4] = dcval;
- dataptr[DCTSIZE*5] = dcval;
- dataptr[DCTSIZE*6] = dcval;
- dataptr[DCTSIZE*7] = dcval;
-
+ DCTELEM dcval = (DCTELEM) DESCALE ((INT32) dataptr[0], PASS1_BITS + 3);
+
+ dataptr[DCTSIZE * 0] = dcval;
+ dataptr[DCTSIZE * 1] = dcval;
+ dataptr[DCTSIZE * 2] = dcval;
+ dataptr[DCTSIZE * 3] = dcval;
+ dataptr[DCTSIZE * 4] = dcval;
+ dataptr[DCTSIZE * 5] = dcval;
+ dataptr[DCTSIZE * 6] = dcval;
+ dataptr[DCTSIZE * 7] = dcval;
+
dataptr++; /* advance pointer to next column */
continue;
}
@@ -324,48 +305,52 @@ gst_idct_int_idct (DCTBLOCK data)
/* Even part: reverse the even part of the forward DCT. */
/* The rotator is sqrt(2)*c(-6). */
- z2 = (INT32) dataptr[DCTSIZE*2];
- z3 = (INT32) dataptr[DCTSIZE*6];
+ z2 = (INT32) dataptr[DCTSIZE * 2];
+ z3 = (INT32) dataptr[DCTSIZE * 6];
- z1 = MULTIPLY(z2 + z3, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(z3, - FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(z2, FIX_0_765366865);
+ z1 = MULTIPLY (z2 + z3, FIX_0_541196100);
+ tmp2 = z1 + MULTIPLY (z3, -FIX_1_847759065);
+ tmp3 = z1 + MULTIPLY (z2, FIX_0_765366865);
- tmp0 = ((INT32) dataptr[DCTSIZE*0] + (INT32) dataptr[DCTSIZE*4]) << CONST_BITS;
- tmp1 = ((INT32) dataptr[DCTSIZE*0] - (INT32) dataptr[DCTSIZE*4]) << CONST_BITS;
+ tmp0 =
+ ((INT32) dataptr[DCTSIZE * 0] +
+ (INT32) dataptr[DCTSIZE * 4]) << CONST_BITS;
+ tmp1 =
+ ((INT32) dataptr[DCTSIZE * 0] -
+ (INT32) dataptr[DCTSIZE * 4]) << CONST_BITS;
tmp10 = tmp0 + tmp3;
tmp13 = tmp0 - tmp3;
tmp11 = tmp1 + tmp2;
tmp12 = tmp1 - tmp2;
-
+
/* Odd part per figure 8; the matrix is unitary and hence its
* transpose is its inverse. i0..i3 are y7,y5,y3,y1 respectively.
*/
- tmp0 = (INT32) dataptr[DCTSIZE*7];
- tmp1 = (INT32) dataptr[DCTSIZE*5];
- tmp2 = (INT32) dataptr[DCTSIZE*3];
- tmp3 = (INT32) dataptr[DCTSIZE*1];
+ tmp0 = (INT32) dataptr[DCTSIZE * 7];
+ tmp1 = (INT32) dataptr[DCTSIZE * 5];
+ tmp2 = (INT32) dataptr[DCTSIZE * 3];
+ tmp3 = (INT32) dataptr[DCTSIZE * 1];
z1 = tmp0 + tmp3;
z2 = tmp1 + tmp2;
z3 = tmp0 + tmp2;
z4 = tmp1 + tmp3;
- z5 = MULTIPLY(z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
-
- tmp0 = MULTIPLY(tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
- tmp1 = MULTIPLY(tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
- tmp2 = MULTIPLY(tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
- tmp3 = MULTIPLY(tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
- z1 = MULTIPLY(z1, - FIX_0_899976223); /* sqrt(2) * (c7-c3) */
- 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) */
-
+ z5 = MULTIPLY (z3 + z4, FIX_1_175875602); /* sqrt(2) * c3 */
+
+ tmp0 = MULTIPLY (tmp0, FIX_0_298631336); /* sqrt(2) * (-c1+c3+c5-c7) */
+ tmp1 = MULTIPLY (tmp1, FIX_2_053119869); /* sqrt(2) * ( c1+c3-c5+c7) */
+ tmp2 = MULTIPLY (tmp2, FIX_3_072711026); /* sqrt(2) * ( c1+c3+c5-c7) */
+ tmp3 = MULTIPLY (tmp3, FIX_1_501321110); /* sqrt(2) * ( c1+c3-c5-c7) */
+ z1 = MULTIPLY (z1, -FIX_0_899976223); /* sqrt(2) * (c7-c3) */
+ 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;
-
+
tmp0 += z1 + z3;
tmp1 += z2 + z4;
tmp2 += z2 + z3;
@@ -373,23 +358,23 @@ gst_idct_int_idct (DCTBLOCK data)
/* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
- dataptr[DCTSIZE*0] = (DCTELEM) DESCALE(tmp10 + tmp3,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*7] = (DCTELEM) DESCALE(tmp10 - tmp3,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*1] = (DCTELEM) DESCALE(tmp11 + tmp2,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*6] = (DCTELEM) DESCALE(tmp11 - tmp2,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*2] = (DCTELEM) DESCALE(tmp12 + tmp1,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*5] = (DCTELEM) DESCALE(tmp12 - tmp1,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*3] = (DCTELEM) DESCALE(tmp13 + tmp0,
- CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSIZE*4] = (DCTELEM) DESCALE(tmp13 - tmp0,
- CONST_BITS+PASS1_BITS+3);
-
+ dataptr[DCTSIZE * 0] = (DCTELEM) DESCALE (tmp10 + tmp3,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 7] = (DCTELEM) DESCALE (tmp10 - tmp3,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 1] = (DCTELEM) DESCALE (tmp11 + tmp2,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 6] = (DCTELEM) DESCALE (tmp11 - tmp2,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 2] = (DCTELEM) DESCALE (tmp12 + tmp1,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 5] = (DCTELEM) DESCALE (tmp12 - tmp1,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 3] = (DCTELEM) DESCALE (tmp13 + tmp0,
+ CONST_BITS + PASS1_BITS + 3);
+ dataptr[DCTSIZE * 4] = (DCTELEM) DESCALE (tmp13 - tmp0,
+ CONST_BITS + PASS1_BITS + 3);
+
dataptr++; /* advance pointer to next column */
}
}
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