AVAudioPlayerNode scheduleFile：atTime：completionHandler：不调用完成处理程序

Question

[AVAudioPlayerNode scheduleFile:atTime:completionHandler:]被记录为“在文件完全播放或播放器停止后调用”，但在文件完全播放之前被调用。即使通过轮询，似乎也没有任何方法可以确定文件是否已完成播放。

我已经将10个简短的声音文件排队，然后记录每个文件的时间和lastRenderTime；它还大约每秒钟轮询一次玩家状态。

日志输出

2015-09-27 19:24:21.193 AVAudioEngineCompletion[9946:369939] playing 0 <AVAudioTime 0x6080000a8280: 30642.368875 s 0 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:21.194 AVAudioEngineCompletion[9946:369939] playing 1 <AVAudioTime 0x6080000a7f80: 30642.368875 s 0 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:21.601 AVAudioEngineCompletion[9946:369939] playing 2 <AVAudioTime 0x6000000a60c0: 30642.777492 s 18020 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:22.101 AVAudioEngineCompletion[9946:369939] playing 3 <AVAudioTime 0x6080000a63c0: 30643.276721 s 40036 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:22.270 AVAudioEngineCompletion[9946:369853] 1 - <AVAudioTime 0x6000000a2d00: 30643.439261 s 47204 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:22.600 AVAudioEngineCompletion[9946:369939] playing 4 <AVAudioTime 0x6080000a63c0: 30643.775950 s 62052 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:23.099 AVAudioEngineCompletion[9946:369939] playing 5 <AVAudioTime 0x6080000a63c0: 30644.275179 s 84068 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:23.374 AVAudioEngineCompletion[9946:369853] 2 - <AVAudioTime 0x6080000a63c0: 30644.542209 s 95844 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:23.587 AVAudioEngineCompletion[9946:369939] playing 6 <AVAudioTime 0x6080000a63c0: 30644.762799 s 105572 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:24.086 AVAudioEngineCompletion[9946:369939] playing 7 <AVAudioTime 0x6080000a63c0: 30645.262028 s 127588 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:24.180 AVAudioEngineCompletion[9946:369853] 3 - <AVAudioTime 0x6000000a57c0: 30645.354907 s 131684 fr (/44100 Hz) 1.000000 rs>
2015-09-27 19:24:24.585 AVAudioEngineCompletion[9946:369939] playing 8 <AVAudioTime 0x6080000a63c0: 30645.761258 s 149604 fr (/44100 Hz) 1.000001 rs>
2015-09-27 19:24:25.085 AVAudioEngineCompletion[9946:369939] playing 9 <AVAudioTime 0x6000000a5820: 30646.260487 s 171620 fr (/44100 Hz) 1.000001 rs>
2015-09-27 19:24:25.579 AVAudioEngineCompletion[9946:369853] 4 - <AVAudioTime 0x6080000a63c0: 30646.748107 s 193124 fr (/44100 Hz) 1.000001 rs>
2015-09-27 19:24:26.547 AVAudioEngineCompletion[9946:369853] 5 - <AVAudioTime 0x6080000a63c0: 30647.711735 s 235620 fr (/44100 Hz) 1.000001 rs>
2015-09-27 19:24:27.180 AVAudioEngineCompletion[9946:369853] 6 - <AVAudioTime 0x6000000a1860: 30648.350284 s 263780 fr (/44100 Hz) 1.000000 rs>

我使用AVAudioPlayerNode而不是高级API来播放声音文件，因为我需要控制输出设备。

通过选定的输出设备播放音频或什至与视频相关的音频的任务对于QuickTime来说是微不足道的，但是在更高级别的AVFoundation API中没有直接的模拟来设置音频设备

Answer 1

要在播放完成后获得回调，您想调用一个稍微不同的函数，如下所示：

playerNode.scheduleFile(clip.audioFile!, at: nil, completionCallbackType: AVAudioPlayerNodeCompletionCallbackType.dataPlayedBack, completionHandler: { (completionType) in
    self.didFinish()
})