无需重新下载即可重播AVPlayerItem / AVPlayer

时间:2015-01-07 05:14:04

标签: ios objective-c audio avplayer avplayeritem

我有一个AVPlayer类,它设置了流式传输音频文件。它有点长,所以我不能在这里发布整个事情。我所坚持的是如何允许用户在完成一次听完之后重放音频文件。第一次完成后,我正确收到通知AVPlayerItemDidPlayToEndTimeNotification。当我重播它时,我立即收到相同的通知,阻止我重播它。

如何重置此选项,AVPlayerItem并不认为它已播放音频文件?我可以释放所有内容并重新设置它,但我相信这会迫使用户再次下载音频文件,这是毫无意义和缓慢的。

以下是我认为相关的课程的一些部分。尝试重播文件时得到的输出如下所示。前两行正是我所期望的,但第三行是一个惊喜。

  

正在播放没有计时器
音频播放器已播放音频

- (id) initWithURL : (NSString *) urlString
{
    self = [super init];
    if (self) {
        self.isPlaying = NO;
        self.verbose = YES;

        if (self.verbose) NSLog(@"url: %@", urlString);
        NSURL *url = [NSURL URLWithString:urlString];

        self.playerItem = [AVPlayerItem playerItemWithURL:url];
        self.player = [[AVPlayer alloc] initWithPlayerItem:self.playerItem];

        [self determineAudioPlayTime : self.playerItem];

        self.lengthOfAudioInSeconds = @0.0f;

        [self.player addObserver:self forKeyPath:@"status" options:0 context:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(itemDidFinishPlaying:) name:AVPlayerItemDidPlayToEndTimeNotification object:self.playerItem];
    }

    return self;
}

// this is what gets called when the user clicks the play button after they have 
// listened to the file and the AVPlayerItemDidPlayToEndTimeNotification has been received
- (void) playAgain {
    [self.playerItem seekToTime:kCMTimeZero];
    [self toggleState];
}

- (void) toggleState {
    self.isPlaying = !self.isPlaying;

    if (self.isPlaying) {
        if (self.verbose) NSLog(@"is playing");
        [self.player play];

        if (!timer) {
            NSLog(@"no timer");
            CMTime audioTimer = CMTimeMake(0, 1);
            [self.player seekToTime:audioTimer];

            timer = [NSTimer scheduledTimerWithTimeInterval:1.0
                                                     target:self
                                                   selector:@selector(updateProgress)
                                                   userInfo:nil
                                                    repeats:YES];
        }

    } else {
        if (self.verbose) NSLog(@"paused");
        [self.player pause];
    }
}

-(void)itemDidFinishPlaying:(NSNotification *) notification {
    if (self.verbose) NSLog(@"audio player has finished playing audio");
    [[NSNotificationCenter defaultCenter] postNotificationName:@"audioFinished" object:self];
    [timer invalidate];
    timer = nil;
    self.totalSecondsPlayed = [NSNumber numberWithInt:0];
    self.isPlaying = NO;
}

1 个答案:

答案 0 :(得分:15)

当玩家收到 AVPlayerItemDidPlayToEndTimeNotification

时,您可以调用seekToTime方法
func itemDidFinishPlaying() {
    self.player.seekToTime(kCMTimeZero)
    self.player.play()
}