gdImageXbmCtx    2829 gd/gd.c        	_php_image_output_ctx(INTERNAL_FUNCTION_PARAM_PASSTHRU, PHP_GDIMG_TYPE_XBM, "GIF", gdImageXbmCtx);
gdImageXbmCtx     284 gd/libgd/gd.h  void gdImageXbmCtx(gdImagePtr image, char* file_name, int fg, gdIOCtx * out);