Wait until file load in Superpowered Library

Question

I looking for some solution for waiting until SuperpoweredAdvancedAudioPlayer open the file. I make ios objective-c application where I want to play multiple tracks at the same time. But when I try start tracks in this way:

    player1->open([[[NSBundle mainBundle] pathForResource:[[tracksNamesBigArray objectAtIndex:row] objectAtIndex:0]ofType:@"mp3"] fileSystemRepresentation]);
        player1->play(true);

    player2->open([[[NSBundle mainBundle] pathForResource:[[tracksNamesBigArray objectAtIndex:row] objectAtIndex:1] ofType:@"mp3"] fileSystemRepresentation]);
    player2->play(true);

    player3->open([[[NSBundle mainBundle] pathForResource:[[tracksNamesBigArray objectAtIndex:row] objectAtIndex:2] ofType:@"mp3"] fileSystemRepresentation]);
    player3->play(true);

    player4->open([[[NSBundle mainBundle] pathForResource:[[tracksNamesBigArray objectAtIndex:row] objectAtIndex:3] ofType:@"mp3"] fileSystemRepresentation]);
    player4->play(true);

or when I wrap this in functions and make something like this:

  [self openPlayers:row]
  [self playAll];

It doesn't start play perfectly in the same time, one or 2 last tracks starts with .5s-.8s delay(in first example delay is larger than in second). How to wait until open is successful and then start to play? I did't find any function for that in superpowered documentation.

Answer 1

To check when SuperpoweredAdvancedAudioPlayer open and load files I must use SuperpoweredAdvancedPlayerEvent_LoadSuccess in playerEventCallback. Then sync start of players are much better.

This is my new playerEventCallback:

void playerEventCallback1(void *clientData, SuperpoweredAdvancedAudioPlayerEvent event, void *value) {
    RootViewController *self = (__bridge RootViewController *)clientData;
    switch(event){
        case SuperpoweredAdvancedAudioPlayerEvent_LoadSuccess:{
            RootViewController *self = (__bridge RootViewController *)clientData;
            NSLog(@"Player1 load success");
            self->loadIndicator++;
            break;
        }
        case SuperpoweredAdvancedAudioPlayerEvent_EOF:{
            self->player1->pause();
            self->player1->setPosition(0, true, false);
            break;} 
    }
}