c++ - SDL_Mixer 再次播放时，从随机位置开始一段时间然后从头开始

Question

嗨，我正在尝试在这里触发多个音乐播放，这里有一些代码。

    Mix_Music *mix_list[MUSIC_COUNT] ;
    //init music with SDL
    int result = 0;
    int flags = MIX_INIT_MP3;


    if (SDL_Init(SDL_INIT_AUDIO) < 0) {
        printf("Failed to init SDL\n");
        exit(1);
    }
    if (flags != (result = Mix_Init(flags))) {
        printf("Could not initialize mixer (result: %d).\n", result);
        printf("Mix_Init: %s\n", Mix_GetError());
        exit(1);
    }
    //load music
    Mix_OpenAudio(44100, AUDIO_S16SYS, 2, 640);
    for (int i = 0 ; i < musiclist.size() ; ++i){
        mix_list[i] = Mix_LoadMUS(musiclist[i].c_str());
    }

然后在一个循环中，

for (; ;){
            //trigger from here, some code detect if there's a new music need to be played


            //play sound here
            if (!Mix_PlayingMusic()){
                //if not playing just start fresh play
                std::cout << "Start Play " << musiclist[markerIds[0]]  << std::endl ;
                Mix_FadeInMusic(mix_list[markerIds[0]],1,1000) ;
            }
            else{
                //only if change to next music
                if (lastDetected != markerIds[0]){
                    std::cout << "Fading out current" << std::endl ;

                     //first need to fade out current
                    while(!Mix_FadeOutMusic(2000) && Mix_PlayingMusic()) {
                        // wait for any fades to complete
                        SDL_Delay(100);
                    }
                    Mix_HaltMusic() ;

                    //then start the one
                    //problem happens here
                    //there will always be several seconds it plays from the middle somewhere, then plays from the beginning.
                    Mix_FadeInMusic(mix_list[markerIds[0]],1,4000) ;

                }

            }
      }

我的问题在代码中列出，问题是播放之前播放的音乐时，无论 Mix_FadeInMusic ()或 Mix_PlayMusic()总是先从随机位置播放音乐几秒钟，然后从头开始。但我所需要的，只是顺利进行。

操作系统:Ubuntu 16.04
SDL:2.0.4
混音器:2.0.1

Answer 1

我自己想通了，这实际上是 mp3 问题。与 Ubuntu 16.04 捆绑的 SDL 库在播放一些 mp3 文件时几乎没有问题。因此，在我将文件转换为 OGG 并使用 int flags = MIX_INIT_OGG; 之后问题刚刚消失。