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The question sounds very simple but I couldn't find a way to check if a track uri is correct.

For example, the normal procedure to play a track by a given valid track uri spotify:track:5Z7ygHQo02SUrFmcgpwsKW is:

1) get sp_link* by sp_link_create_from_string(const char *$track_uri)

2) get sp_track* by sp_link_as_track(sp_link*)

3) sp_track_add_ref(sp_track*)

4) if sp_track_error() returns SP_ERROR_OK, or SP_ERROR_IS_LOADING but metadata_updated and

SP_ERROR_OK then sp_session_player_load and sp_session_player_play to load and play the track.

5) sp_track_release() and sp_session_player_unload() when it's the end of track.

When I try to do to play with a correct uri sp_track_error() returns SP_ERROR_IS_LOADING,

metadata_updated never gets called, and of course the program hangs.I have check many uri

and get the same result.

Did I miss something or misunderstand the APIs?

This is the main loop:

    pthread_mutex_lock(&g_notify_mutex);
    for(;;)
    {

        if (next_timeout == 0)
        {
            while(!g_notify_do && !g_playback_done)
            {
                pthread_cond_wait(&g_notify_cond, &g_notify_mutex);
            }

        }
        else
        {
            struct timespec ts;

#if _POSIX_TIMERS > 0
            clock_gettime(CLOCK_REALTIME, &ts);
#else
            struct timeval tv;
            gettimeofday(&tv, NULL);
            TIMEVAL_TO_TIMESPEC(&tv, &ts);
#endif
            printf("%d\n",next_timeout);
            if((ts.tv_nsec+(next_timeout % 1000) * 1000000)>=1000000000)
            {
                ts.tv_nsec += (next_timeout % 1000) * 1000000-1000000000;
                ts.tv_sec += next_timeout / 1000+1;
            }
            else
            {
                ts.tv_sec += next_timeout / 1000;
                ts.tv_nsec += (next_timeout % 1000) * 1000000;
            }
            pthread_cond_timedwait(&g_notify_cond, &g_notify_mutex, &ts);
        }

        g_notify_do = 0;
        pthread_mutex_unlock(&g_notify_mutex);

         g_currenttrack= sp_link_as_track(sp_link_create_from_string(spotify:track:1NrJYpdAi7uosDRPmSYrsG));
         sp_track_add_ref(g_currenttrack);

         if (sp_track_error( g_currenttrack) == SP_ERROR_OK) {

                sp_session_player_load(g_sess, g_currenttrack);
                sp_session_player_play(g_sess, 1);
          }
        do
        {
            sp_session_process_events(g_sess, &next_timeout);
        }
        while (next_timeout == 0);

        pthread_mutex_lock(&g_notify_mutex);
}

I found that metadata_update called by main loop,but when the track has been created this loop will hang out for a long time(about 290s).

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1 回答 1

0

metadata_updated除非被调用，否则不会被sp_session_process_events()调用。您的代码停滞 300 秒的原因是因为在登录后，sp_session_process_events()将下一次调用超时设置为 300 秒。在第 3 步之后，您可以强制自己的通知主线程，这将解决问题。不幸的是，我不知道为什么 libspotify 此时不发送通知主线程。我想我们都在这里遗漏了一些东西。

于 2013-12-21T03:25:21.803 回答