SDL_VideoModeOK - Check to see if a particular video mode is supported.

SDL_VideoModeOK  returns  0  if  the  requested mode is not supported under any bit depth, or returns the
       bits-per-pixel of the closest available mode with the given width, height  and  requested  surface  flags
       (see SDL_SetVideoMode).

       The bits-per-pixel value returned is only a suggested mode. You can usually request and bpp you want when
       setting the video mode and SDL will emulate that color depth with a shadow video surface.

       The arguments to SDL_VideoModeOK are the same ones you would pass to SDL_SetVideoMode

       SDL_Surface *screen;
       Uint32 bpp;
       .
       .
       .
       printf("Checking mode 640x480@16bpp.
       ");
       bpp=SDL_VideoModeOK(640, 480, 16, SDL_HWSURFACE);

       if(!bpp){
         printf("Mode not available.
       ");
         exit(-1);
       }

       printf("SDL Recommends 640x480@%dbpp.
       ", bpp);
       screen=SDL_SetVideoMode(640, 480, bpp, SDL_HWSURFACE);
       .
       .

       SDL_VideoModeOK - Check to see if a particular video mode is supported.

SDL_SetVideoMode, SDL_GetVideoInfo

SDL                                          Tue 11 Sep 2001, 23:01                           SDL_VideoModeOK(3)

#include"SDL.h"intSDL_VideoModeOK(intwidth,intheight,intbpp,Uint32flags);