@@ -408,7 +408,7 @@ void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color,

 }

 static void blend_pixel(uint8_t *dst, unsigned src, unsigned alpha,

-                        uint8_t *mask, int mask_linesize, int l2depth,

+                        const uint8_t *mask, int mask_linesize, int l2depth,

                         unsigned w, unsigned h, unsigned shift, unsigned xm0)

 {

     unsigned xm, x, y, t = 0;

@@ -432,7 +432,7 @@ static void blend_pixel(uint8_t *dst, unsigned src, unsigned alpha,

 static void blend_line_hv(uint8_t *dst, int dst_delta,

                           unsigned src, unsigned alpha,

-                          uint8_t *mask, int mask_linesize, int l2depth, int w,

+                          const uint8_t *mask, int mask_linesize, int l2depth, int w,

                           unsigned hsub, unsigned vsub,

                           int xm, int left, int right, int hband)

 {

@@ -457,12 +457,13 @@ static void blend_line_hv(uint8_t *dst, int dst_delta,

 void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color,

                    uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h,

-                   uint8_t *mask,  int mask_linesize, int mask_w, int mask_h,

+                   const uint8_t *mask,  int mask_linesize, int mask_w, int mask_h,

                    int l2depth, unsigned endianness, int x0, int y0)

 {

     unsigned alpha, nb_planes, nb_comp, plane, comp;

     int xm0, ym0, w_sub, h_sub, x_sub, y_sub, left, right, top, bottom, y;

-    uint8_t *p0, *p, *m;

+    uint8_t *p0, *p;

+    const uint8_t *m;

     clip_interval(dst_w, &x0, &mask_w, &xm0);

     clip_interval(dst_h, &y0, &mask_h, &ym0);

@@ -130,7 +130,7 @@ void ff_blend_rectangle(FFDrawContext *draw, FFDrawColor *color,

  */

 void ff_blend_mask(FFDrawContext *draw, FFDrawColor *color,

                    uint8_t *dst[], int dst_linesize[], int dst_w, int dst_h,

-                   uint8_t *mask, int mask_linesize, int mask_w, int mask_h,

+                   const uint8_t *mask, int mask_linesize, int mask_w, int mask_h,

                    int l2depth, unsigned endianness, int x0, int y0);

 /**