c++ - SDL_Mixer 音频不播放

Question

好了，问题来了。我开始学习 SDL，并想为我为学校项目制作的这个“游戏”添加一些音频。音频无法从我的程序中播放，但我阅读和下载的教程代码中包含音频并可以播放。我真的很困惑为什么我的音频无法播放，但我知道这是正确的。

1. mp3 和代码在同一个文件夹
2. mp3 以 44100 Hz 的频率播放，正如 Mixer 所期望的那样。

非常感谢任何帮助，这是代码

#include <iostream>
#include <fstream>
#include <stdlib.h>
#include "SDL/SDL.h"
#include "SDL2/SDL.h"
#include <SDL2/SDL_mixer.h>


//The attributes of the screen
const int SCREEN_WIDTH = 640;
const int SCREEN_HEIGHT = 640;
const int SCREEN_BPP = 32;

//The surfaces that will be used
Mix_Music *music = NULL;
SDL_Surface *wall = NULL;
SDL_Surface *path = NULL;
SDL_Surface *breadcrumb = NULL;
SDL_Surface *deadend = NULL;
SDL_Surface *screen = NULL;
SDL_Event event;

using namespace std;
////////////////////////////////////////////////////////////
SDL_Surface *load_image( string filename )
{
    SDL_Surface* loadedImage = NULL;        //Temporary storage for the image that's loaded
    SDL_Surface* optimizedImage = NULL;    //The optimized image that will be used
    loadedImage = SDL_LoadBMP( filename.c_str() );    //Load the image
    if( loadedImage != NULL )    //If nothing went wrong in loading the image
    {
        optimizedImage = SDL_DisplayFormat( loadedImage );        //Create an optimized image
        SDL_FreeSurface( loadedImage );        //Free the old image
    }
    return optimizedImage;    //Return the optimized image
}
////////////////////////////////////////////////////////////
void apply_surface( int x, int y, SDL_Surface* source, SDL_Surface* destination )
{
    SDL_Rect offset;    //Make a temporary rectangle to hold the offsets
    offset.x = x;    //Give the offsets to the rectangle
    offset.y = y;
    SDL_BlitSurface( source, NULL, destination, &offset );    //Blit th
}
using namespace std;

char MAZE[22][22];
////////////////////////////////////////////////////////////////////////
void Initialize()
{
    int X,Y;
    for (X=0;X<22;X++)
        for (Y=0;Y<22;Y++)
            MAZE[X][Y]='0';
    ifstream fin ("maze.txt");
    if (fin.is_open())
    {
        for (X=1;X<21;X++)
            for (Y=1;Y<21;Y++)
                fin>>MAZE[X][Y];
        fin.close();
    }
    else cout << "Unable to open maze.txt\n";
    return;
}
////////////////////////////////////////////////////////////////////////
void PrintMaze()
{   
    int gx,gy;
    system("clear");
    for (int Y=1;Y<21;Y++)
    {
        for (int X=1;X<21;X++)
        {
            gx=32*(X-1);
            gy=32*(Y-1);
            cout<<MAZE[X][Y];
            switch (MAZE[X][Y])
            {
                case '.':
                    apply_surface( gx, gy, wall, screen );
                break;
                case 'X':
                    apply_surface( gx, gy, path, screen );
                break;
                case '*':
                    apply_surface( gx, gy, breadcrumb, screen );
                break;
            }
        }cout<<"\n";

    }
    if( SDL_Flip( screen ) == -1 ) return;
    cout<<flush;
    system("sleep .2");
    return;
}
////////////////////////////////////////////////////////////////////////
int Solve(int X, int Y)
{
    if ((X==20)&&(Y==20))
    {
        cout<<"("<<X<<","<<Y<<")";
        return 1;
    }
    if (MAZE[X][Y]!='X') return 0;
    else
    {
        PrintMaze();
        MAZE[X][Y]='*';
        for (int A=(X+1);A>=(X-1);A--)
            for (int B=(Y+1);B>=(Y-1);B--)
                if (Solve(A,B)==1)
                {
                    cout<<"("<<X<<","<<Y<<")";
                    return 1;
                }
    }
    MAZE[X][Y]='.';
    return 0;
}
////////////////////////////////////////////////////////////////////////
int main()
{
    if( SDL_Init( SDL_INIT_EVERYTHING ) == -1 )    //Initialize all SDL subsystems
        return 1;
    screen = SDL_SetVideoMode( SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_BPP, SDL_SWSURFACE );    //Set up the screen
    if( screen == NULL )    //If there was an error in setting up the screen
        return 1;  
   //Initialize SDL_mixer
        if( Mix_OpenAudio( 44100, MIX_DEFAULT_FORMAT, 2, 2048 ) < 0 )
        {
                    printf( "SDL_mixer could not initialize! SDL_mixer Error: %s\n", Mix_GetError() );
        }
    SDL_WM_SetCaption( "Dank Solver", NULL );    //Set the window caption
    wall = load_image( "wall.bmp" );    //Load the images
    path = load_image( "path.bmp" );
    breadcrumb = load_image( "breadcrumb.bmp" );
    deadend = load_image( "deadend.bmp" );
    music = Mix_LoadMUS( "mlg.mp3" );
      if( music == NULL )
    {
        cout<<"Music Error"; 
        return 0;   
    }

    Initialize();
    Mix_PlayMusic ( music, -1 );
    PrintMaze();
    if (Solve(1,1)==0) cout<<"No Solution\n";
    else cout<<"Solution Found\n";
    SDL_FreeSurface( wall );
    SDL_FreeSurface( path );
    SDL_FreeSurface( breadcrumb );
    SDL_FreeSurface( deadend );
    Mix_FreeMusic ( music );
    Mix_CloseAudio();
    SDL_Quit();         //Quit SDL
    return 0;
}

Answer 1

如果知道输出内容会很棒。如果它说“音乐错误”那么你也应该打印 Mix_GetError()

printf("Music Error %s",Mix_GetError());

一般来说，无法播放 MP3 是因为缺少在不支持 mp3 的情况下构建的编解码器/混音器。您还可以在播放文件时检查是否有任何错误。从文档中复制并粘贴:

if(Mix_PlayMusic(music, -1)==-1) {
    printf("Mix_PlayMusic: %s\n", Mix_GetError());
    // well, there's no music, but most games don't break without music...
}