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-rw-r--r--libmpeg2/idct.c289
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diff --git a/libmpeg2/idct.c b/libmpeg2/idct.c
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+/*
+ * idct.c
+ * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
+ * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of mpeg2dec, a free MPEG-2 video stream decoder.
+ * See http://libmpeg2.sourceforge.net/ for updates.
+ *
+ * mpeg2dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * mpeg2dec is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include "mpeg2.h"
+#include "attributes.h"
+#include "mpeg2_internal.h"
+
+#define W1 2841 /* 2048 * sqrt (2) * cos (1 * pi / 16) */
+#define W2 2676 /* 2048 * sqrt (2) * cos (2 * pi / 16) */
+#define W3 2408 /* 2048 * sqrt (2) * cos (3 * pi / 16) */
+#define W5 1609 /* 2048 * sqrt (2) * cos (5 * pi / 16) */
+#define W6 1108 /* 2048 * sqrt (2) * cos (6 * pi / 16) */
+#define W7 565 /* 2048 * sqrt (2) * cos (7 * pi / 16) */
+
+/* idct main entry point */
+void (* mpeg2_idct_copy) (int16_t * block, uint8_t * dest, int stride);
+void (* mpeg2_idct_add) (int last, int16_t * block,
+ uint8_t * dest, int stride);
+
+/*
+ * In legal streams, the IDCT output should be between -384 and +384.
+ * In corrupted streams, it is possible to force the IDCT output to go
+ * to +-3826 - this is the worst case for a column IDCT where the
+ * column inputs are 16-bit values.
+ */
+uint8_t mpeg2_clip[3840 * 2 + 256];
+#define CLIP(i) ((mpeg2_clip + 3840)[i])
+
+#if 0
+#define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
+do { \
+ t0 = W0 * d0 + W1 * d1; \
+ t1 = W0 * d1 - W1 * d0; \
+} while (0)
+#else
+#define BUTTERFLY(t0,t1,W0,W1,d0,d1) \
+do { \
+ int tmp = W0 * (d0 + d1); \
+ t0 = tmp + (W1 - W0) * d1; \
+ t1 = tmp - (W1 + W0) * d0; \
+} while (0)
+#endif
+
+static inline void idct_row (int16_t * const block)
+{
+ int d0, d1, d2, d3;
+ int a0, a1, a2, a3, b0, b1, b2, b3;
+ int t0, t1, t2, t3;
+
+ /* shortcut */
+ if (likely (!(block[1] | ((int32_t *)block)[1] | ((int32_t *)block)[2] |
+ ((int32_t *)block)[3]))) {
+ uint32_t tmp = (uint16_t) (block[0] >> 1);
+ tmp |= tmp << 16;
+ ((int32_t *)block)[0] = tmp;
+ ((int32_t *)block)[1] = tmp;
+ ((int32_t *)block)[2] = tmp;
+ ((int32_t *)block)[3] = tmp;
+ return;
+ }
+
+ d0 = (block[0] << 11) + 2048;
+ d1 = block[1];
+ d2 = block[2] << 11;
+ d3 = block[3];
+ t0 = d0 + d2;
+ t1 = d0 - d2;
+ BUTTERFLY (t2, t3, W6, W2, d3, d1);
+ a0 = t0 + t2;
+ a1 = t1 + t3;
+ a2 = t1 - t3;
+ a3 = t0 - t2;
+
+ d0 = block[4];
+ d1 = block[5];
+ d2 = block[6];
+ d3 = block[7];
+ BUTTERFLY (t0, t1, W7, W1, d3, d0);
+ BUTTERFLY (t2, t3, W3, W5, d1, d2);
+ b0 = t0 + t2;
+ b3 = t1 + t3;
+ t0 -= t2;
+ t1 -= t3;
+ b1 = ((t0 + t1) >> 8) * 181;
+ b2 = ((t0 - t1) >> 8) * 181;
+
+ block[0] = (a0 + b0) >> 12;
+ block[1] = (a1 + b1) >> 12;
+ block[2] = (a2 + b2) >> 12;
+ block[3] = (a3 + b3) >> 12;
+ block[4] = (a3 - b3) >> 12;
+ block[5] = (a2 - b2) >> 12;
+ block[6] = (a1 - b1) >> 12;
+ block[7] = (a0 - b0) >> 12;
+}
+
+static inline void idct_col (int16_t * const block)
+{
+ int d0, d1, d2, d3;
+ int a0, a1, a2, a3, b0, b1, b2, b3;
+ int t0, t1, t2, t3;
+
+ d0 = (block[8*0] << 11) + 65536;
+ d1 = block[8*1];
+ d2 = block[8*2] << 11;
+ d3 = block[8*3];
+ t0 = d0 + d2;
+ t1 = d0 - d2;
+ BUTTERFLY (t2, t3, W6, W2, d3, d1);
+ a0 = t0 + t2;
+ a1 = t1 + t3;
+ a2 = t1 - t3;
+ a3 = t0 - t2;
+
+ d0 = block[8*4];
+ d1 = block[8*5];
+ d2 = block[8*6];
+ d3 = block[8*7];
+ BUTTERFLY (t0, t1, W7, W1, d3, d0);
+ BUTTERFLY (t2, t3, W3, W5, d1, d2);
+ b0 = t0 + t2;
+ b3 = t1 + t3;
+ t0 -= t2;
+ t1 -= t3;
+ b1 = ((t0 + t1) >> 8) * 181;
+ b2 = ((t0 - t1) >> 8) * 181;
+
+ block[8*0] = (a0 + b0) >> 17;
+ block[8*1] = (a1 + b1) >> 17;
+ block[8*2] = (a2 + b2) >> 17;
+ block[8*3] = (a3 + b3) >> 17;
+ block[8*4] = (a3 - b3) >> 17;
+ block[8*5] = (a2 - b2) >> 17;
+ block[8*6] = (a1 - b1) >> 17;
+ block[8*7] = (a0 - b0) >> 17;
+}
+
+static void mpeg2_idct_copy_c (int16_t * block, uint8_t * dest,
+ const int stride)
+{
+ int i;
+
+ for (i = 0; i < 8; i++)
+ idct_row (block + 8 * i);
+ for (i = 0; i < 8; i++)
+ idct_col (block + i);
+ do {
+ dest[0] = CLIP (block[0]);
+ dest[1] = CLIP (block[1]);
+ dest[2] = CLIP (block[2]);
+ dest[3] = CLIP (block[3]);
+ dest[4] = CLIP (block[4]);
+ dest[5] = CLIP (block[5]);
+ dest[6] = CLIP (block[6]);
+ dest[7] = CLIP (block[7]);
+
+ ((int32_t *)block)[0] = 0; ((int32_t *)block)[1] = 0;
+ ((int32_t *)block)[2] = 0; ((int32_t *)block)[3] = 0;
+
+ dest += stride;
+ block += 8;
+ } while (--i);
+}
+
+static void mpeg2_idct_add_c (const int last, int16_t * block,
+ uint8_t * dest, const int stride)
+{
+ int i;
+
+ if (last != 129 || (block[0] & (7 << 4)) == (4 << 4)) {
+ for (i = 0; i < 8; i++)
+ idct_row (block + 8 * i);
+ for (i = 0; i < 8; i++)
+ idct_col (block + i);
+ do {
+ dest[0] = CLIP (block[0] + dest[0]);
+ dest[1] = CLIP (block[1] + dest[1]);
+ dest[2] = CLIP (block[2] + dest[2]);
+ dest[3] = CLIP (block[3] + dest[3]);
+ dest[4] = CLIP (block[4] + dest[4]);
+ dest[5] = CLIP (block[5] + dest[5]);
+ dest[6] = CLIP (block[6] + dest[6]);
+ dest[7] = CLIP (block[7] + dest[7]);
+
+ ((int32_t *)block)[0] = 0; ((int32_t *)block)[1] = 0;
+ ((int32_t *)block)[2] = 0; ((int32_t *)block)[3] = 0;
+
+ dest += stride;
+ block += 8;
+ } while (--i);
+ } else {
+ int DC;
+
+ DC = (block[0] + 64) >> 7;
+ block[0] = block[63] = 0;
+ i = 8;
+ do {
+ dest[0] = CLIP (DC + dest[0]);
+ dest[1] = CLIP (DC + dest[1]);
+ dest[2] = CLIP (DC + dest[2]);
+ dest[3] = CLIP (DC + dest[3]);
+ dest[4] = CLIP (DC + dest[4]);
+ dest[5] = CLIP (DC + dest[5]);
+ dest[6] = CLIP (DC + dest[6]);
+ dest[7] = CLIP (DC + dest[7]);
+ dest += stride;
+ } while (--i);
+ }
+}
+
+void mpeg2_idct_init (uint32_t accel)
+{
+#ifdef ARCH_X86
+ if (accel & MPEG2_ACCEL_X86_SSE2) {
+ mpeg2_idct_copy = mpeg2_idct_copy_sse2;
+ mpeg2_idct_add = mpeg2_idct_add_sse2;
+ mpeg2_idct_mmx_init ();
+ } else if (accel & MPEG2_ACCEL_X86_MMXEXT) {
+ mpeg2_idct_copy = mpeg2_idct_copy_mmxext;
+ mpeg2_idct_add = mpeg2_idct_add_mmxext;
+ mpeg2_idct_mmx_init ();
+ } else if (accel & MPEG2_ACCEL_X86_MMX) {
+ mpeg2_idct_copy = mpeg2_idct_copy_mmx;
+ mpeg2_idct_add = mpeg2_idct_add_mmx;
+ mpeg2_idct_mmx_init ();
+ } else
+#endif
+#ifdef ARCH_PPC
+ if (accel & MPEG2_ACCEL_PPC_ALTIVEC) {
+ mpeg2_idct_copy = mpeg2_idct_copy_altivec;
+ mpeg2_idct_add = mpeg2_idct_add_altivec;
+ mpeg2_idct_altivec_init ();
+ } else
+#endif
+#ifdef ARCH_ALPHA
+ if (accel & MPEG2_ACCEL_ALPHA_MVI) {
+ mpeg2_idct_copy = mpeg2_idct_copy_mvi;
+ mpeg2_idct_add = mpeg2_idct_add_mvi;
+ mpeg2_idct_alpha_init ();
+ } else if (accel & MPEG2_ACCEL_ALPHA) {
+ int i;
+
+ mpeg2_idct_copy = mpeg2_idct_copy_alpha;
+ mpeg2_idct_add = mpeg2_idct_add_alpha;
+ mpeg2_idct_alpha_init ();
+ for (i = -3840; i < 3840 + 256; i++)
+ CLIP(i) = (i < 0) ? 0 : ((i > 255) ? 255 : i);
+ } else
+#endif
+ {
+ int i, j;
+
+ mpeg2_idct_copy = mpeg2_idct_copy_c;
+ mpeg2_idct_add = mpeg2_idct_add_c;
+ for (i = -3840; i < 3840 + 256; i++)
+ CLIP(i) = (i < 0) ? 0 : ((i > 255) ? 255 : i);
+ for (i = 0; i < 64; i++) {
+ j = mpeg2_scan_norm[i];
+ mpeg2_scan_norm[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
+ j = mpeg2_scan_alt[i];
+ mpeg2_scan_alt[i] = ((j & 0x36) >> 1) | ((j & 0x09) << 2);
+ }
+ }
+}
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