Native Android music

int AudioManager::load_music(const char* source_file)
{
  // Attempt to open the music file
  music_file = SDL_RWFromFile(source_file, "rb"); // read binary
  ASSERT(music_file, source_file); // print the name of the file being opened

  #ifdef __ANDROID__
    // initialise RWops structure from file in SD card
    FILE* sdcard = fopen("/sdcard/data/music.ogg", "wb");
    ASSERT(sdcard, "Opening file to export music from APK to filesystem");
    SDL_RWops* sdcard_rw = SDL_RWFromFP(sdcard, SDL_TRUE); // autoclose
    ASSERT(sdcard_rw, "Creating SDL_RWops structure from file pointer");

    // externalise music data from APK assets folder to the SD card
    char buffer[io::MAX_BLOCKS];
    int read_amount = SDL_RWread(music_file, buffer, 1, io::MAX_BLOCKS);
    while(read_amount > 0)
    {
      SDL_RWwrite(sdcard_rw, buffer, 1, read_amount);
      SDL_RWseek(music_file, SEEK_CUR, read_amount*io::BLOCK_SIZE);
      read_amount = SDL_RWread(music_file, buffer, 1, io::MAX_BLOCKS);
    }
    SDL_RWclose(music_file);
    SDL_RWclose(sdcard_rw);

    // load the music from the filesystem, not the archive
    sdcard = fopen("/sdcard/data/music.ogg", "rb");
    ASSERT(sdcard, "Opening file to import music from filesystem");
    music_file = SDL_RWFromFP(sdcard, SDL_TRUE); // autoclose
    ASSERT(music_file, "Creating SDL_RWops structure from file pointer");

  #endif //ifdef __ANDROID__

  // Attempt to read the file contents as music
  ASSERT_MIX(music = Mix_LoadMUS_RW(music_file),
              "Extracting music from SDL_RWops structure");

  /// NB - file is NOT closed as music data must be streamed


  // Success !
  return EXIT_SUCCESS;
}