SDL_mixer exception at Mix

SDL_mixer exception at Mix_PlayMusic

Member

Posts: 20
Joined: 2006.06

Post: #1

Aug 31, 2006 — 08:03 PM

I have never used SDL_mixer and I am a novice when it comes to real debugging with xcode. Anyway, I was attempting to get mixer working and have immediately run into an issue. Basically, when I attempt to call Mix_PlayMusic it explodes.

My pertinent code (based of the gpwiki code:

Code:

#include <cstdio>

#include <cstdlib>

#include <string>

#include "SDL.h"

#include "SDL_image.h"

#include "SDL_mixer.h"

#define COLORKEY 255, 255, 255

const std::string asset_path = "assets/";

const std::string music_filename = asset_path + "some_song_on_my_disk.ogg";

int main( int argc, char *argv[ ]) {

    Uint32 initflags = SDL_INIT_VIDEO;

    SDL_Surface *screen;

    Uint8 video_bpp = 0;

    Uint32 videoflags = SDL_SWSURFACE | SDL_DOUBLEBUF;// | SDL_FULLSCREEN | SDL_NOFRAME;

    int done;

  SDL_Event event;

    /* Initialize the SDL library */

    if ( SDL_Init( initflags ) < 0 ) {

        fprintf(stderr, "Couldn't initialize SDL: %s\n",

            SDL_GetError( ));

        exit( 1 );

    }

    /* Set 640x480 video mode */

    screen = SDL_SetVideoMode( 640, 480, video_bpp, videoflags );

  if ( !screen ) {

        fprintf( stderr, "Couldn't set 640x480x%d video mode: %s\n",

             video_bpp, SDL_GetError( ));

        SDL_Quit( );

        exit( 2 );

    }

  printf( "Loading music\n" );

  Mix_Music *music = NULL;

  music = Mix_LoadMUS( music_filename.c_str( ));

  if( !music ) {

      printf( "Unable to load Ogg file: %s\n", Mix_GetError( ));

    SDL_Quit( );

      exit( 5 );

  }

  printf( "Music loaded\n" );

  if(Mix_PlayMusic(music, 0) == -1) {

      printf("Unable to play Ogg file: %s\n", Mix_GetError());

      SDL_Quit( );

    exit( 6 );

  }

  done = 0;

    while ( !done ) {

        /* Check for events */

        while ( SDL_PollEvent( &event )) {

            switch ( event.type ) {

                case SDL_MOUSEMOTION:

                    break;

                case SDL_MOUSEBUTTONDOWN:

                    break;

        /* Any keypress quits the app... */

                case SDL_KEYDOWN:

                case SDL_QUIT:

                    done = 1;

                    break;

                default:

                    break;

            }

        }

    SDL_Flip(screen); //Refresh the screen

    SDL_Delay( 50 ); //Wait a bit :)

    }

  Mix_HaltMusic();

  Mix_FreeMusic(music);

  Mix_CloseAudio();

    /* Clean up the SDL library */

    SDL_Quit( );

    return( 0 );

}

The stack trace that xcode gives me jumps into Mix_PlayMusic and below that Mix_FadeInMusicPos (some assembly dump). Any ideas? Anyone know how to get xcode to tell you what exactly triggered the exception/halt of program?

sealfin

Moderator

Posts: 680
Joined: 2002.04

Post: #2

Sep 1, 2006 — 02:29 AM

From a quick look at your code, you haven't called Mix_OpenAudio() anywhere prior to the loading/playing of the music...

Edit: also, I believe you need to pass the flags ( SDL_INIT_VIDEO | SDL_INIT_AUDIO ) to SDL_Init()...

Mark Bishop

kordova

Member

Posts: 20
Joined: 2006.06

Post: #3

Sep 1, 2006 — 04:09 AM

Oh wow. I was just following http://gpwiki.org/index.php/C:Using_SDL_...music_file without putting much thought into it. Thanks a lot.

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