lavfi/drawutils: attempt to fix subsampling.

libavfilter/drawutils.c

@@ -93,7 +93,7 @@ int ff_fill_line_with_color(uint8_t *line[4], int pixel_step[4], int w, uint8_t
             int hsub1 = (plane == 1 || plane == 2) ? hsub : 0;
 
             pixel_step[plane] = 1;
-            line_size = (w >> hsub1) * pixel_step[plane];
+            line_size = FF_CEIL_RSHIFT(w, hsub1) * pixel_step[plane];
             line[plane] = av_malloc(line_size);
             memset(line[plane], dst_color[plane], line_size);
         }
@@ -112,11 +112,13 @@ void ff_draw_rectangle(uint8_t *dst[4], int dst_linesize[4],
     for (plane = 0; plane < 4 && dst[plane]; plane++) {
         int hsub1 = plane == 1 || plane == 2 ? hsub : 0;
         int vsub1 = plane == 1 || plane == 2 ? vsub : 0;
+        int width  = FF_CEIL_RSHIFT(w, hsub1);
+        int height = FF_CEIL_RSHIFT(h, vsub1);
 
         p = dst[plane] + (y >> vsub1) * dst_linesize[plane];
-        for (i = 0; i < (h >> vsub1); i++) {
+        for (i = 0; i < height; i++) {
             memcpy(p + (x >> hsub1) * pixelstep[plane],
-                   src[plane], (w >> hsub1) * pixelstep[plane]);
+                   src[plane], width * pixelstep[plane]);
             p += dst_linesize[plane];
         }
     }
@@ -132,11 +134,13 @@ void ff_copy_rectangle(uint8_t *dst[4], int dst_linesize[4],
     for (plane = 0; plane < 4 && dst[plane]; plane++) {
         int hsub1 = plane == 1 || plane == 2 ? hsub : 0;
         int vsub1 = plane == 1 || plane == 2 ? vsub : 0;
+        int width  = FF_CEIL_RSHIFT(w, hsub1);
+        int height = FF_CEIL_RSHIFT(h, vsub1);
 
         p = dst[plane] + (y >> vsub1) * dst_linesize[plane];
-        for (i = 0; i < (h >> vsub1); i++) {
+        for (i = 0; i < height; i++) {
             memcpy(p + (x >> hsub1) * pixelstep[plane],
-                   src[plane] + src_linesize[plane]*(i+(y2>>vsub1)), (w >> hsub1) * pixelstep[plane]);
+                   src[plane] + src_linesize[plane]*(i+(y2>>vsub1)), width * pixelstep[plane]);
             p += dst_linesize[plane];
         }
     }
@@ -233,8 +237,8 @@ void ff_copy_rectangle2(FFDrawContext *draw,
     for (plane = 0; plane < draw->nb_planes; plane++) {
         p = pointer_at(draw, src, src_linesize, plane, src_x, src_y);
         q = pointer_at(draw, dst, dst_linesize, plane, dst_x, dst_y);
-        wp = (w >> draw->hsub[plane]) * draw->pixelstep[plane];
-        hp = (h >> draw->vsub[plane]);
+        wp = FF_CEIL_RSHIFT(w, draw->hsub[plane]) * draw->pixelstep[plane];
+        hp = FF_CEIL_RSHIFT(h, draw->vsub[plane]);
         for (y = 0; y < hp; y++) {
             memcpy(q, p, wp);
             p += src_linesize[plane];
@@ -252,8 +256,8 @@ void ff_fill_rectangle(FFDrawContext *draw, FFDrawColor *color,
 
     for (plane = 0; plane < draw->nb_planes; plane++) {
         p0 = pointer_at(draw, dst, dst_linesize, plane, dst_x, dst_y);
-        wp = (w >> draw->hsub[plane]);
-        hp = (h >> draw->vsub[plane]);
+        wp = FF_CEIL_RSHIFT(w, draw->hsub[plane]);
+        hp = FF_CEIL_RSHIFT(h, draw->vsub[plane]);
         if (!hp)
             return;
         p = p0;