if (over->overpicref)
blend_image(ctx, mainpic, over->overpicref, over->x, over->y);
ret = ff_filter_frame(ctx->outputs[0], mainpic);
if (over->overpicref)
blend_image(ctx, mainpic, over->overpicref, over->x, over->y);
ret = ff_filter_frame(ctx->outputs[0], mainpic);