wmv2: move IDCT to its own DSP context.

This allows us to remove FF_IDCT_WMV2, which serves no practical purpose
other than to be able to select the WMV2 IDCT for MPEG (or vice versa)
and get corrupt output.

Fate tests for all wmv2-related tests change, because (for some obscure
reason) they forced use of the MPEG IDCT. You would get the same changes
previously by not using -idct simple in the fate test (or replacing it
with -idct auto).

1 files changed, 145 insertions, 0 deletions

diff --git a/libavcodec/wmv2dsp.c b/libavcodec/wmv2dsp.c
new file mode 100644
index 0000000000..85a9db1d75
--- /dev/null
+++ b/libavcodec/wmv2dsp.c
@@ -0,0 +1,145 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "libavutil/attributes.h"
+#include "libavutil/common.h"
+#include "avcodec.h"
+#include "wmv2dsp.h"
+
+#define W0 2048
+#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 W4 2048 /* 2048*sqrt (2)*cos (4*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) */
+
+static void wmv2_idct_row(short * b)
+{
+    int s1, s2;
+    int a0, a1, a2, a3, a4, a5, a6, a7;
+
+    /* step 1 */
+    a1 = W1 * b[1] + W7 * b[7];
+    a7 = W7 * b[1] - W1 * b[7];
+    a5 = W5 * b[5] + W3 * b[3];
+    a3 = W3 * b[5] - W5 * b[3];
+    a2 = W2 * b[2] + W6 * b[6];
+    a6 = W6 * b[2] - W2 * b[6];
+    a0 = W0 * b[0] + W0 * b[4];
+    a4 = W0 * b[0] - W0 * b[4];
+
+    /* step 2 */
+    s1 = (181 * (a1 - a5 + a7 - a3) + 128) >> 8; // 1, 3, 5, 7
+    s2 = (181 * (a1 - a5 - a7 + a3) + 128) >> 8;
+
+    /* step 3 */
+    b[0] = (a0 + a2 + a1 + a5 + (1 << 7)) >> 8;
+    b[1] = (a4 + a6 + s1      + (1 << 7)) >> 8;
+    b[2] = (a4 - a6 + s2      + (1 << 7)) >> 8;
+    b[3] = (a0 - a2 + a7 + a3 + (1 << 7)) >> 8;
+    b[4] = (a0 - a2 - a7 - a3 + (1 << 7)) >> 8;
+    b[5] = (a4 - a6 - s2      + (1 << 7)) >> 8;
+    b[6] = (a4 + a6 - s1      + (1 << 7)) >> 8;
+    b[7] = (a0 + a2 - a1 - a5 + (1 << 7)) >> 8;
+}
+
+static void wmv2_idct_col(short * b)
+{
+    int s1, s2;
+    int a0, a1, a2, a3, a4, a5, a6, a7;
+
+    /* step 1, with extended precision */
+    a1 = (W1 * b[8 * 1] + W7 * b[8 * 7] + 4) >> 3;
+    a7 = (W7 * b[8 * 1] - W1 * b[8 * 7] + 4) >> 3;
+    a5 = (W5 * b[8 * 5] + W3 * b[8 * 3] + 4) >> 3;
+    a3 = (W3 * b[8 * 5] - W5 * b[8 * 3] + 4) >> 3;
+    a2 = (W2 * b[8 * 2] + W6 * b[8 * 6] + 4) >> 3;
+    a6 = (W6 * b[8 * 2] - W2 * b[8 * 6] + 4) >> 3;
+    a0 = (W0 * b[8 * 0] + W0 * b[8 * 4]    ) >> 3;
+    a4 = (W0 * b[8 * 0] - W0 * b[8 * 4]    ) >> 3;
+
+    /* step 2 */
+    s1 = (181 * (a1 - a5 + a7 - a3) + 128) >> 8;
+    s2 = (181 * (a1 - a5 - a7 + a3) + 128) >> 8;
+
+    /* step 3 */
+    b[8 * 0] = (a0 + a2 + a1 + a5 + (1 << 13)) >> 14;
+    b[8 * 1] = (a4 + a6 + s1      + (1 << 13)) >> 14;
+    b[8 * 2] = (a4 - a6 + s2      + (1 << 13)) >> 14;
+    b[8 * 3] = (a0 - a2 + a7 + a3 + (1 << 13)) >> 14;
+
+    b[8 * 4] = (a0 - a2 - a7 - a3 + (1 << 13)) >> 14;
+    b[8 * 5] = (a4 - a6 - s2      + (1 << 13)) >> 14;
+    b[8 * 6] = (a4 + a6 - s1      + (1 << 13)) >> 14;
+    b[8 * 7] = (a0 + a2 - a1 - a5 + (1 << 13)) >> 14;
+}
+
+static void wmv2_idct_add_c(uint8_t *dest, int line_size, DCTELEM *block)
+{
+    int i;
+
+    for (i = 0; i < 64; i += 8)
+        wmv2_idct_row(block + i);
+    for (i = 0; i < 8; i++)
+        wmv2_idct_col(block + i);
+
+    for (i = 0; i < 8; i++) {
+        dest[0] = av_clip_uint8(dest[0] + block[0]);
+        dest[1] = av_clip_uint8(dest[1] + block[1]);
+        dest[2] = av_clip_uint8(dest[2] + block[2]);
+        dest[3] = av_clip_uint8(dest[3] + block[3]);
+        dest[4] = av_clip_uint8(dest[4] + block[4]);
+        dest[5] = av_clip_uint8(dest[5] + block[5]);
+        dest[6] = av_clip_uint8(dest[6] + block[6]);
+        dest[7] = av_clip_uint8(dest[7] + block[7]);
+        dest += line_size;
+        block += 8;
+    }
+}
+
+static void wmv2_idct_put_c(uint8_t *dest, int line_size, DCTELEM *block)
+{
+    int i;
+
+    for (i = 0; i < 64; i += 8)
+        wmv2_idct_row(block + i);
+    for (i = 0; i < 8; i++)
+        wmv2_idct_col(block + i);
+
+    for (i = 0; i < 8; i++) {
+        dest[0] = av_clip_uint8(block[0]);
+        dest[1] = av_clip_uint8(block[1]);
+        dest[2] = av_clip_uint8(block[2]);
+        dest[3] = av_clip_uint8(block[3]);
+        dest[4] = av_clip_uint8(block[4]);
+        dest[5] = av_clip_uint8(block[5]);
+        dest[6] = av_clip_uint8(block[6]);
+        dest[7] = av_clip_uint8(block[7]);
+        dest += line_size;
+        block += 8;
+    }
+}
+
+av_cold void ff_wmv2dsp_init(WMV2DSPContext *c)
+{
+    c->idct_add  = wmv2_idct_add_c;
+    c->idct_put  = wmv2_idct_put_c;
+    c->idct_perm = FF_NO_IDCT_PERM;
+}