dsputil: Split off HuffYUV encoding bits into their own context

Also shorten HuffYUV context member names to avoid clutter.

1 files changed, 84 insertions, 0 deletions

diff --git a/libavcodec/huffyuvencdsp.c b/libavcodec/huffyuvencdsp.c
new file mode 100644
index 0000000000..6c30877737
--- /dev/null
+++ b/libavcodec/huffyuvencdsp.c
@@ -0,0 +1,84 @@
+/*
+ * 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 "config.h"
+#include "libavutil/attributes.h"
+#include "huffyuvencdsp.h"
+#include "mathops.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 diff_bytes_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w)
+{
+    long i;
+
+#if !HAVE_FAST_UNALIGNED
+    if ((long) src2 & (sizeof(long) - 1)) {
+        for (i = 0; i + 7 < w; i += 8) {
+            dst[i + 0] = src1[i + 0] - src2[i + 0];
+            dst[i + 1] = src1[i + 1] - src2[i + 1];
+            dst[i + 2] = src1[i + 2] - src2[i + 2];
+            dst[i + 3] = src1[i + 3] - src2[i + 3];
+            dst[i + 4] = src1[i + 4] - src2[i + 4];
+            dst[i + 5] = src1[i + 5] - src2[i + 5];
+            dst[i + 6] = src1[i + 6] - src2[i + 6];
+            dst[i + 7] = src1[i + 7] - src2[i + 7];
+        }
+    } else
+#endif
+    for (i = 0; i <= w - (int) sizeof(long); i += sizeof(long)) {
+        long a = *(long *) (src1 + i);
+        long b = *(long *) (src2 + i);
+        *(long *) (dst + i) = ((a | pb_80) - (b & pb_7f)) ^
+                              ((a ^ b ^ pb_80) & pb_80);
+    }
+    for (; i < w; i++)
+        dst[i + 0] = src1[i + 0] - src2[i + 0];
+}
+
+static void sub_hfyu_median_pred_c(uint8_t *dst, const uint8_t *src1,
+                                   const uint8_t *src2, int w,
+                                   int *left, int *left_top)
+{
+    int i;
+    uint8_t l, lt;
+
+    l  = *left;
+    lt = *left_top;
+
+    for (i = 0; i < w; i++) {
+        const int pred = mid_pred(l, src1[i], (l + src1[i] - lt) & 0xFF);
+        lt     = src1[i];
+        l      = src2[i];
+        dst[i] = l - pred;
+    }
+
+    *left     = l;
+    *left_top = lt;
+}
+
+av_cold void ff_huffyuvencdsp_init(HuffYUVEncDSPContext *c)
+{
+    c->diff_bytes           = diff_bytes_c;
+    c->sub_hfyu_median_pred = sub_hfyu_median_pred_c;
+
+    if (ARCH_X86)
+        ff_huffyuvencdsp_init_x86(c);
+}