dsputil: Split off HuffYUV decoding bits into their own context

Also shorten HuffYUV context member names to avoid clutter.

1 files changed, 132 insertions, 0 deletions

diff --git a/libavcodec/huffyuvdsp.c b/libavcodec/huffyuvdsp.c
new file mode 100644
index 0000000000..b5a714d072
--- /dev/null
+++ b/libavcodec/huffyuvdsp.c
@@ -0,0 +1,132 @@
+/*
+ * 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 <stdint.h>
+
+#include "config.h"
+#include "libavutil/attributes.h"
+#include "mathops.h"
+#include "huffyuvdsp.h"
+
+// 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
+#define pb_7f (~0UL / 255 * 0x7f)
+#define pb_80 (~0UL / 255 * 0x80)
+
+static void add_bytes_c(uint8_t *dst, uint8_t *src, int w)
+{
+    long i;
+
+    for (i = 0; i <= w - (int) sizeof(long); i += sizeof(long)) {
+        long a = *(long *) (src + i);
+        long b = *(long *) (dst + i);
+        *(long *) (dst + i) = ((a & pb_7f) + (b & pb_7f)) ^ ((a ^ b) & pb_80);
+    }
+    for (; i < w; i++)
+        dst[i + 0] += src[i + 0];
+}
+
+static void add_hfyu_median_pred_c(uint8_t *dst, const uint8_t *src1,
+                                   const uint8_t *diff, int w,
+                                   int *left, int *left_top)
+{
+    int i;
+    uint8_t l, lt;
+
+    l  = *left;
+    lt = *left_top;
+
+    for (i = 0; i < w; i++) {
+        l      = mid_pred(l, src1[i], (l + src1[i] - lt) & 0xFF) + diff[i];
+        lt     = src1[i];
+        dst[i] = l;
+    }
+
+    *left     = l;
+    *left_top = lt;
+}
+
+static int add_hfyu_left_pred_c(uint8_t *dst, const uint8_t *src, int w,
+                                int acc)
+{
+    int i;
+
+    for (i = 0; i < w - 1; i++) {
+        acc   += src[i];
+        dst[i] = acc;
+        i++;
+        acc   += src[i];
+        dst[i] = acc;
+    }
+
+    for (; i < w; i++) {
+        acc   += src[i];
+        dst[i] = acc;
+    }
+
+    return acc;
+}
+
+#if HAVE_BIGENDIAN
+#define B 3
+#define G 2
+#define R 1
+#define A 0
+#else
+#define B 0
+#define G 1
+#define R 2
+#define A 3
+#endif
+static void add_hfyu_left_pred_bgr32_c(uint8_t *dst, const uint8_t *src,
+                                       int w, int *red, int *green,
+                                       int *blue, int *alpha)
+{
+    int i, r = *red, g = *green, b = *blue, a = *alpha;
+
+    for (i = 0; i < w; i++) {
+        b += src[4 * i + B];
+        g += src[4 * i + G];
+        r += src[4 * i + R];
+        a += src[4 * i + A];
+
+        dst[4 * i + B] = b;
+        dst[4 * i + G] = g;
+        dst[4 * i + R] = r;
+        dst[4 * i + A] = a;
+    }
+
+    *red   = r;
+    *green = g;
+    *blue  = b;
+    *alpha = a;
+}
+#undef B
+#undef G
+#undef R
+#undef A
+
+av_cold void ff_huffyuvdsp_init(HuffYUVDSPContext *c)
+{
+    c->add_bytes                = add_bytes_c;
+    c->add_hfyu_median_pred     = add_hfyu_median_pred_c;
+    c->add_hfyu_left_pred       = add_hfyu_left_pred_c;
+    c->add_hfyu_left_pred_bgr32 = add_hfyu_left_pred_bgr32_c;
+
+    if (ARCH_X86)
+        ff_huffyuvdsp_init_x86(c);
+}