MacOS QT SDL2 嵌入到Qlabel,显示在了整个widget上

screen = SDL_CreateWindowFrom((void *)ui->label->winId());
sdlRender = SDL_CreateRenderer(screen,-1,0);texture = SDL_CreateTexture(sdlRender,SDL_PIXELFORMAT_IYUV, SDL_TEXTUREACCESS_STREAMING,width,height); //width,height实际视频的宽高
SDL_UpdateTexture(texture, nullptr, pixels, pitch);
SDL_RenderClear(sdlRender);
SDL_RenderCopy(sdlRender, texture, nullptr, nullptr); //后面2个参数设置了也无效
SDL_RenderPresent(sdlRender);
请问怎么设置才能不让他显示到外面去