videoscale: Added NV support for 4Tap resize

https://bugzilla.gnome.org/show_bug.cgi?id=736845

gst/videoscale/gstvideoscale.c

@@ -413,7 +413,7 @@ get_formats_filter (GstVideoScaleMethod method)
           "ARGB, BGRA, ABGR, AYUV, ARGB64, AYUV64, "
           "RGB, BGR, v308, YUY2, YVYU, UYVY, "
           "GRAY8, GRAY16_LE, GRAY16_BE, I420, YV12, "
-          "Y444, Y42B, Y41B, RGB16, RGB15 }");
+          "Y444, Y42B, Y41B, RGB16, RGB15, NV12, NV21 }");
       return gst_static_caps_get (&fourtap_filter);
     }
     case GST_VIDEO_SCALE_LANCZOS:
@@ -1392,6 +1392,10 @@ do_scale (GstVideoFilter * filter, VSImage dest[4], VSImage src[4])
           vs_image_scale_linear_Y (&dest[0], &src[0], videoscale->tmp_buf);
           vs_image_scale_linear_NV12 (&dest[1], &src[1], videoscale->tmp_buf);
           break;
+        case GST_VIDEO_SCALE_4TAP:
+          vs_image_scale_4tap_Y (&dest[0], &src[0], videoscale->tmp_buf);
+          vs_image_scale_4tap_NV12 (&dest[1], &src[1], videoscale->tmp_buf);
+          break;
         default:
           goto unknown_mode;
       }

gst/videoscale/vs_4tap.c

@@ -86,6 +86,11 @@ static void vs_scanline_resample_4tap_AYUV64 (uint16_t * dest, uint16_t * src,
 static void vs_scanline_merge_4tap_AYUV64 (uint16_t * dest, uint16_t * src1,
     uint16_t * src2, uint16_t * src3, uint16_t * src4, int n, int acc);
 
+static void vs_scanline_merge_4tap_NV (uint8_t * dest, uint8_t * src1,
+    uint8_t * src2, uint8_t * src3, uint8_t * src4, int n, int acc);
+static void vs_scanline_resample_4tap_NV (uint8_t * dest, uint8_t * src, int n,
+    int src_width, int *xacc, int increment);
+
 static double
 vs_4tap_func (double x)
 {
@@ -188,6 +193,133 @@ vs_scanline_merge_4tap_Y (uint8_t * dest, uint8_t * src1, uint8_t * src2,
 }
 
 
+static void
+vs_scanline_resample_4tap_NV (uint8_t * dest, uint8_t * src,
+    int n, int src_width, int *xacc, int increment)
+{
+  int i;
+  int j;
+  int acc;
+  int x;
+  int u, v;
+  int stride = src_width * 2;
+
+  acc = *xacc;
+  for (i = 0; i < n; i++) {
+    j = acc >> 16;
+    j *= 2;
+    x = (acc & 0xff00) >> 8;
+    if (j - 1 >= 0 && j + 2 < src_width) {
+      u = vs_4tap_taps[x][0] * src[j - 2];
+      v = vs_4tap_taps[x][0] * src[j - 1];
+      u += vs_4tap_taps[x][1] * src[j];
+      v += vs_4tap_taps[x][1] * src[j + 1];
+      u += vs_4tap_taps[x][2] * src[j + 2];
+      v += vs_4tap_taps[x][2] * src[j + 3];
+      u += vs_4tap_taps[x][3] * src[j + 4];
+      v += vs_4tap_taps[x][3] * src[j + 5];
+    } else {
+      u = vs_4tap_taps[x][0] * src[CLAMP (j - 2, 0, stride - 1)];
+      v = vs_4tap_taps[x][0] * src[CLAMP (j - 1, 0, stride - 1)];
+      u += vs_4tap_taps[x][1] * src[CLAMP (j, 0, stride - 1)];
+      v += vs_4tap_taps[x][1] * src[CLAMP (j + 1, 0, stride - 1)];
+      u += vs_4tap_taps[x][2] * src[CLAMP (j + 2, 0, stride - 1)];
+      v += vs_4tap_taps[x][2] * src[CLAMP (j + 3, 0, stride - 1)];
+      u += vs_4tap_taps[x][3] * src[CLAMP (j + 4, 0, stride - 1)];
+      v += vs_4tap_taps[x][3] * src[CLAMP (j + 5, 0, stride - 1)];
+    }
+    u += (1 << (SHIFT - 1));
+    v += (1 << (SHIFT - 1));
+    dest[i * 2] = CLAMP (u >> SHIFT, 0, 255);
+    dest[i * 2 + 1] = CLAMP (v >> SHIFT, 0, 255);
+    acc += increment;
+  }
+  *xacc = acc;
+}
+
+static void
+vs_scanline_merge_4tap_NV (uint8_t * dest, uint8_t * src1, uint8_t * src2,
+    uint8_t * src3, uint8_t * src4, int n, int acc)
+{
+  int i;
+  int val;
+  int a, b, c, d;
+
+  acc = (acc >> 8) & 0xff;
+  a = vs_4tap_taps[acc][0];
+  b = vs_4tap_taps[acc][1];
+  c = vs_4tap_taps[acc][2];
+  d = vs_4tap_taps[acc][3];
+  for (i = 0; i < (n * 2); i++) {
+    val = a * src1[i];
+    val += b * src2[i];
+    val += c * src3[i];
+    val += d * src4[i];
+    val += (1 << (SHIFT - 1));
+    dest[i] = CLAMP (val >> SHIFT, 0, 255);
+  }
+}
+
+void
+vs_image_scale_4tap_NV12 (const VSImage * dest, const VSImage * src,
+    uint8_t * tmpbuf)
+{
+  int yacc;
+  int y_increment;
+  int x_increment;
+  int i;
+  int j;
+  int xacc;
+  int k;
+
+  if (dest->height == 1)
+    y_increment = 0;
+  else
+    y_increment = ((src->height - 1) << 16) / (dest->height - 1);
+
+  if (dest->width == 1)
+    x_increment = 0;
+  else
+    x_increment = ((src->width - 1) << 16) / (dest->width - 1);
+
+  k = 0;
+  /* The below loop is to initialize the 4 buffers present in tmpbuf
+     For scaling there are used in cyclic way, so they need to be
+     initialized before entering the main loop */
+  for (i = 0; i < 4; i++) {
+    xacc = 0;
+    vs_scanline_resample_4tap_NV (tmpbuf + i * dest->stride,
+        src->pixels + CLAMP (i, 0, src->height - 1) * src->stride, dest->width,
+        src->width, &xacc, x_increment);
+  }
+
+  yacc = 0;
+  for (i = 0; i < dest->height; i++) {
+    uint8_t *t0, *t1, *t2, *t3;
+
+    j = yacc >> 16;
+
+    while (j > k) {
+      k++;
+      if (k + 3 < src->height) {
+        xacc = 0;
+        vs_scanline_resample_4tap_NV (tmpbuf + ((k + 3) & 3) * dest->stride,
+            src->pixels + (k + 3) * src->stride,
+            dest->width, src->width, &xacc, x_increment);
+      }
+    }
+    t0 = tmpbuf + (CLAMP (j - 1, 0, src->height - 1) & 3) * dest->stride;
+    t1 = tmpbuf + (CLAMP (j, 0, src->height - 1) & 3) * dest->stride;
+    t2 = tmpbuf + (CLAMP (j + 1, 0, src->height - 1) & 3) * dest->stride;
+    t3 = tmpbuf + (CLAMP (j + 2, 0, src->height - 1) & 3) * dest->stride;
+    vs_scanline_merge_4tap_NV (dest->pixels + i * dest->stride,
+        t0, t1, t2, t3, dest->width, yacc & 0xffff);
+
+    yacc += y_increment;
+  }
+}
+
+
 void
 vs_image_scale_4tap_Y (const VSImage * dest, const VSImage * src,
     uint8_t * tmpbuf)

gst/videoscale/vs_4tap.h

@@ -36,6 +36,10 @@ G_GNUC_INTERNAL void vs_image_scale_4tap_Y      (const VSImage * dest,
                                                  const VSImage * src,
                                                  uint8_t       * tmpbuf);
 
+G_GNUC_INTERNAL void vs_image_scale_4tap_NV12   (const VSImage * dest,
+                                                 const VSImage * src,
+                                                 uint8_t       * tmpbuf);
+
 G_GNUC_INTERNAL void vs_image_scale_4tap_RGBA   (const VSImage * dest,
                                                  const VSImage * src,
                                                  uint8_t       * tmpbuf);