/*
- * jrevdct.c
- *
* This file is part of the Independent JPEG Group's software.
*
* The authors make NO WARRANTY or representation, either express or implied,
*/
/**
- * @file jrevdct.c
+ * @file
* Independent JPEG Group's LLM idct.
*/
-#include "common.h"
+#include "libavutil/common.h"
#include "dsputil.h"
#define EIGHT_BIT_SAMPLES
* Perform the inverse DCT on one block of coefficients.
*/
-void j_rev_dct(DCTBLOCK data)
+void ff_j_rev_dct(DCTBLOCK data)
{
int32_t tmp0, tmp1, tmp2, tmp3;
int32_t tmp10, tmp11, tmp12, tmp13;
tmp3 += z1 + z4;
} else {
/* d1 == 0, d3 != 0, d5 != 0, d7 != 0 */
- z1 = d7;
z2 = d5 + d3;
z3 = d7 + d3;
z5 = MULTIPLY(z3 + d5, FIX_1_175875602);
if (d1) {
/* d1 != 0, d3 == 0, d5 != 0, d7 != 0 */
z1 = d7 + d1;
- z2 = d5;
z3 = d7;
z4 = d5 + d1;
z5 = MULTIPLY(z3 + z4, FIX_1_175875602);
dataptr++; /* advance pointer to next column */
}
}
-
-#undef DCTSIZE
-#define DCTSIZE 4
-#define DCTSTRIDE 8
-
-void j_rev_dct4(DCTBLOCK data)
-{
- int32_t tmp0, tmp1, tmp2, tmp3;
- int32_t tmp10, tmp11, tmp12, tmp13;
- int32_t z1;
- int32_t d0, d2, d4, d6;
- register DCTELEM *dataptr;
- int rowctr;
-
- /* 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. */
-
- data[0] += 4;
-
- 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
- * the AC terms are zero. In that case each output is equal to the
- * DC coefficient (with scale factor as needed).
- * With typical images and quantization tables, half or more of the
- * row DCT calculations can be simplified this way.
- */
-
- register int *idataptr = (int*)dataptr;
-
- d0 = dataptr[0];
- d2 = dataptr[1];
- d4 = dataptr[2];
- d6 = dataptr[3];
-
- if ((d2 | d4 | d6) == 0) {
- /* AC terms all zero */
- if (d0) {
- /* Compute a 32 bit value to assign. */
- DCTELEM dcval = (DCTELEM) (d0 << PASS1_BITS);
- register int v = (dcval & 0xffff) | ((dcval << 16) & 0xffff0000);
-
- idataptr[0] = v;
- idataptr[1] = v;
- }
-
- dataptr += DCTSTRIDE; /* advance pointer to next row */
- continue;
- }
-
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
- if (d6) {
- if (d2) {
- /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
- z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- } else {
- /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
- tmp2 = MULTIPLY(-d6, FIX_1_306562965);
- tmp3 = MULTIPLY(d6, FIX_0_541196100);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- }
- } else {
- if (d2) {
- /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
- tmp2 = MULTIPLY(d2, FIX_0_541196100);
- tmp3 = MULTIPLY(d2, FIX_1_306562965);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- } else {
- /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
- tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
- tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
- }
- }
-
- /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
-
- dataptr[0] = (DCTELEM) DESCALE(tmp10, CONST_BITS-PASS1_BITS);
- dataptr[1] = (DCTELEM) DESCALE(tmp11, CONST_BITS-PASS1_BITS);
- dataptr[2] = (DCTELEM) DESCALE(tmp12, CONST_BITS-PASS1_BITS);
- dataptr[3] = (DCTELEM) DESCALE(tmp13, CONST_BITS-PASS1_BITS);
-
- dataptr += DCTSTRIDE; /* advance pointer to next row */
- }
-
- /* Pass 2: process columns. */
- /* Note that we must descale the results by a factor of 8 == 2**3, */
- /* and also undo the PASS1_BITS scaling. */
-
- dataptr = data;
- 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).
- * On machines with very fast multiplication, it's possible that the
- * test takes more time than it's worth. In that case this section
- * may be commented out.
- */
-
- d0 = dataptr[DCTSTRIDE*0];
- d2 = dataptr[DCTSTRIDE*1];
- d4 = dataptr[DCTSTRIDE*2];
- d6 = dataptr[DCTSTRIDE*3];
-
- /* Even part: reverse the even part of the forward DCT. */
- /* The rotator is sqrt(2)*c(-6). */
- if (d6) {
- if (d2) {
- /* d0 != 0, d2 != 0, d4 != 0, d6 != 0 */
- z1 = MULTIPLY(d2 + d6, FIX_0_541196100);
- tmp2 = z1 + MULTIPLY(-d6, FIX_1_847759065);
- tmp3 = z1 + MULTIPLY(d2, FIX_0_765366865);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- } else {
- /* d0 != 0, d2 == 0, d4 != 0, d6 != 0 */
- tmp2 = MULTIPLY(-d6, FIX_1_306562965);
- tmp3 = MULTIPLY(d6, FIX_0_541196100);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- }
- } else {
- if (d2) {
- /* d0 != 0, d2 != 0, d4 != 0, d6 == 0 */
- tmp2 = MULTIPLY(d2, FIX_0_541196100);
- tmp3 = MULTIPLY(d2, FIX_1_306562965);
-
- tmp0 = (d0 + d4) << CONST_BITS;
- tmp1 = (d0 - d4) << CONST_BITS;
-
- tmp10 = tmp0 + tmp3;
- tmp13 = tmp0 - tmp3;
- tmp11 = tmp1 + tmp2;
- tmp12 = tmp1 - tmp2;
- } else {
- /* d0 != 0, d2 == 0, d4 != 0, d6 == 0 */
- tmp10 = tmp13 = (d0 + d4) << CONST_BITS;
- tmp11 = tmp12 = (d0 - d4) << CONST_BITS;
- }
- }
-
- /* Final output stage: inputs are tmp10..tmp13, tmp0..tmp3 */
-
- dataptr[DCTSTRIDE*0] = tmp10 >> (CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSTRIDE*1] = tmp11 >> (CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSTRIDE*2] = tmp12 >> (CONST_BITS+PASS1_BITS+3);
- dataptr[DCTSTRIDE*3] = tmp13 >> (CONST_BITS+PASS1_BITS+3);
-
- dataptr++; /* advance pointer to next column */
- }
-}
-
-void j_rev_dct2(DCTBLOCK data){
- int d00, d01, d10, d11;
-
- data[0] += 4;
- d00 = data[0+0*DCTSTRIDE] + data[1+0*DCTSTRIDE];
- d01 = data[0+0*DCTSTRIDE] - data[1+0*DCTSTRIDE];
- d10 = data[0+1*DCTSTRIDE] + data[1+1*DCTSTRIDE];
- d11 = data[0+1*DCTSTRIDE] - data[1+1*DCTSTRIDE];
-
- data[0+0*DCTSTRIDE]= (d00 + d10)>>3;
- data[1+0*DCTSTRIDE]= (d01 + d11)>>3;
- data[0+1*DCTSTRIDE]= (d00 - d10)>>3;
- data[1+1*DCTSTRIDE]= (d01 - d11)>>3;
-}
-
-void j_rev_dct1(DCTBLOCK data){
- data[0] = (data[0] + 4)>>3;
-}
-
-#undef FIX
-#undef CONST_BITS
projects / ffmpeg / blobdiff