+uint8_t *mlt_resize_alpha( uint8_t *input, int owidth, int oheight, int iwidth, int iheight )
+{
+ uint8_t *output = NULL;
+
+ if ( input != NULL && ( iwidth != owidth || iheight != oheight ) )
+ {
+ iwidth = iwidth - ( iwidth % 2 );
+ owidth = owidth - ( owidth % 2 );
+
+ output = mlt_pool_alloc( owidth * oheight );
+
+ // Coordinates (0,0 is middle of output)
+ int y;
+
+ // Calculate ranges
+ int out_x_range = owidth / 2;
+ int out_y_range = oheight / 2;
+ int in_x_range = iwidth / 2 < out_x_range ? iwidth / 2 : out_x_range;
+ int in_y_range = iheight / 2 < out_y_range ? iheight / 2 : out_y_range;
+
+ // Output pointers
+ uint8_t *out_line = output;
+ uint8_t *out_ptr = out_line;
+
+ // Calculate a middle and possibly invalid pointer in the input
+ uint8_t *in_middle = input + iwidth * ( iheight / 2 ) + ( iwidth / 2 );
+ int in_line = - in_y_range * iwidth - in_x_range;
+
+ int elements;
+
+ // Fill whole section with black
+ y = out_y_range - ( iheight / 2 );
+ int blank_elements = owidth * y;
+ elements = blank_elements;
+ while ( elements -- )
+ *out_line ++ = 0;
+
+ int active_width = iwidth;
+ int inactive_width = out_x_range - in_x_range;
+ uint8_t *p = NULL;
+ uint8_t *end = NULL;
+
+ // Loop for the entirety of our output height.
+ while ( iheight -- )
+ {
+ // Start at the beginning of the line
+ out_ptr = out_line;
+
+ // Fill the outer part with black
+ elements = inactive_width;
+ while ( elements -- )
+ *out_ptr ++ = 0;
+
+ // We're in the input range for this row.
+ p = in_middle + in_line;
+ end = out_ptr + active_width;
+ while ( out_ptr != end )
+ *out_ptr ++ = *p ++;
+
+ // Fill the outer part with black
+ elements = inactive_width;
+ while ( elements -- )
+ *out_ptr ++ = 0;
+
+ // Move to next input line
+ in_line += iwidth;
+
+ // Move to next output line
+ out_line += owidth;
+ }
+
+ // Fill whole section with black
+ elements = blank_elements;
+ while ( elements -- )
+ *out_line ++ = 0;
+ }
+
+ return output;
+}
+