Move gaussian blur into bitmap handling code

1 files changed, 121 insertions, 0 deletions

diff --git a/libass/ass_bitmap.c b/libass/ass_bitmap.c
index d28d47b..140cca2 100644
--- a/libass/ass_bitmap.c
+++ b/libass/ass_bitmap.c
@@ -322,6 +322,127 @@ static void shift_bitmap(unsigned char *buf, int w, int h, int shift_x,
     }
 }
 
+/*
+ * Gaussian blur.  An fast pure C implementation from MPlayer.
+ */
+static void ass_gauss_blur(unsigned char *buffer, unsigned short *tmp2,
+                           int width, int height, int stride, int *m2,
+                           int r, int mwidth)
+{
+
+    int x, y;
+
+    unsigned char *s = buffer;
+    unsigned short *t = tmp2 + 1;
+    for (y = 0; y < height; y++) {
+        memset(t - 1, 0, (width + 1) * sizeof(short));
+
+        for (x = 0; x < r; x++) {
+            const int src = s[x];
+            if (src) {
+                register unsigned short *dstp = t + x - r;
+                int mx;
+                unsigned *m3 = (unsigned *) (m2 + src * mwidth);
+                for (mx = r - x; mx < mwidth; mx++) {
+                    dstp[mx] += m3[mx];
+                }
+            }
+        }
+
+        for (; x < width - r; x++) {
+            const int src = s[x];
+            if (src) {
+                register unsigned short *dstp = t + x - r;
+                int mx;
+                unsigned *m3 = (unsigned *) (m2 + src * mwidth);
+                for (mx = 0; mx < mwidth; mx++) {
+                    dstp[mx] += m3[mx];
+                }
+            }
+        }
+
+        for (; x < width; x++) {
+            const int src = s[x];
+            if (src) {
+                register unsigned short *dstp = t + x - r;
+                int mx;
+                const int x2 = r + width - x;
+                unsigned *m3 = (unsigned *) (m2 + src * mwidth);
+                for (mx = 0; mx < x2; mx++) {
+                    dstp[mx] += m3[mx];
+                }
+            }
+        }
+
+        s += stride;
+        t += width + 1;
+    }
+
+    t = tmp2;
+    for (x = 0; x < width; x++) {
+        for (y = 0; y < r; y++) {
+            unsigned short *srcp = t + y * (width + 1) + 1;
+            int src = *srcp;
+            if (src) {
+                register unsigned short *dstp = srcp - 1 + width + 1;
+                const int src2 = (src + 128) >> 8;
+                unsigned *m3 = (unsigned *) (m2 + src2 * mwidth);
+
+                int mx;
+                *srcp = 128;
+                for (mx = r - 1; mx < mwidth; mx++) {
+                    *dstp += m3[mx];
+                    dstp += width + 1;
+                }
+            }
+        }
+        for (; y < height - r; y++) {
+            unsigned short *srcp = t + y * (width + 1) + 1;
+            int src = *srcp;
+            if (src) {
+                register unsigned short *dstp = srcp - 1 - r * (width + 1);
+                const int src2 = (src + 128) >> 8;
+                unsigned *m3 = (unsigned *) (m2 + src2 * mwidth);
+
+                int mx;
+                *srcp = 128;
+                for (mx = 0; mx < mwidth; mx++) {
+                    *dstp += m3[mx];
+                    dstp += width + 1;
+                }
+            }
+        }
+        for (; y < height; y++) {
+            unsigned short *srcp = t + y * (width + 1) + 1;
+            int src = *srcp;
+            if (src) {
+                const int y2 = r + height - y;
+                register unsigned short *dstp = srcp - 1 - r * (width + 1);
+                const int src2 = (src + 128) >> 8;
+                unsigned *m3 = (unsigned *) (m2 + src2 * mwidth);
+
+                int mx;
+                *srcp = 128;
+                for (mx = 0; mx < y2; mx++) {
+                    *dstp += m3[mx];
+                    dstp += width + 1;
+                }
+            }
+        }
+        t++;
+    }
+
+    t = tmp2;
+    s = buffer;
+    for (y = 0; y < height; y++) {
+        for (x = 0; x < width; x++) {
+            s[x] = t[x] >> 8;
+        }
+        s += stride;
+        t += width + 1;
+    }
+}
+
 /**
  * \brief Blur with [[1,2,1]. [2,4,2], [1,2,1]] kernel
  * This blur is the same as the one employed by vsfilter.