composite alpha operations, make obscure alpha aware

[melted] / src / modules / core / filter_obscure.c

diff --git a/src/modules/core/filter_obscure.c b/src/modules/core/filter_obscure.c
index e6e7c71..7324293 100644 (file)
--- a/src/modules/core/filter_obscure.c
+++ b/src/modules/core/filter_obscure.c
@@ -148,7 +148,7 @@ static float position_calculate( mlt_filter this, mlt_frame frame )
 /** The averaging function...
 */
 
-void obscure_average( uint8_t *start, int width, int height, int stride )
+void obscure_average( uint8_t *start, int width, int height, int stride, uint8_t *alpha )
 {
        int y;
        int x;
@@ -171,12 +171,33 @@ void obscure_average( uint8_t *start, int width, int height, int stride )
        for ( y = 0; y < height; y ++ )
        {
                uint8_t *p = start + y * stride;
+               uint8_t *z = alpha;
+               
+               if ( z != NULL )
+                       z += y * stride / 2;
+               
                for ( x = 0; x < width / 2; x ++ )
                {
-                       *p ++ = Y;
-                       *p ++ = U;
-                       *p ++ = Y;
-                       *p ++ = V;
+                       if ( z == NULL || ( z != NULL && *z++ > 127 ) )
+                       {
+                               *p ++ = Y;
+                               *p ++ = U;
+                       }
+                       else
+                       {
+                               p += 2;
+                       }
+                               
+                       if ( z == NULL || ( z != NULL && *z++ > 127 ) )
+                       {
+                               
+                               *p ++ = Y;
+                               *p ++ = V;
+                       }
+                       else
+                       {
+                               p += 2;
+                       }
                }
        }
 }
@@ -185,7 +206,7 @@ void obscure_average( uint8_t *start, int width, int height, int stride )
 /** The obscurer rendering function...
 */
 
-static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result )
+static void obscure_render( uint8_t *image, int width, int height, struct geometry_s result, uint8_t *alpha )
 {
        int area_x = result.x;
        int area_y = result.y;
@@ -198,6 +219,9 @@ static void obscure_render( uint8_t *image, int width, int height, struct geomet
        int h;
 
        uint8_t *p = image + area_y * width * 2 + area_x * 2;
+       uint8_t *z = alpha;
+       if ( z != NULL )
+               z += area_y * width + area_x;
 
        for ( w = 0; w < area_w; w += mw )
        {
@@ -205,8 +229,9 @@ static void obscure_render( uint8_t *image, int width, int height, struct geomet
                {
                        int aw = w + mw > area_w ? mw - ( w + mw - area_w ) : mw;
                        int ah = h + mh > area_h ? mh - ( h + mh - area_h ) : mh;
-                       if ( aw > 1 && ah > 1 );
-                               obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2 );
+                       if ( aw > 1 && ah > 1 )
+                               obscure_average( p + h * width * 2 + w * 2, aw, ah, width * 2,
+                                       ( z == NULL ? z : z + h * width + w ) );
                }
        }
 }
@@ -253,7 +278,7 @@ static int filter_get_image( mlt_frame frame, uint8_t **image, mlt_image_format
                        geometry_calculate( &result, &start, &end, position, *width, *height );
 
                        // Now actually render it
-                       obscure_render( *image, *width, *height, result );
+                       obscure_render( *image, *width, *height, result, mlt_frame_get_alpha_mask( frame ) );
                }
        }