我正在尝试使用AVAudioEngine播放AVAudioFile。该代码主要是从Apple Developer在线视频中获取和改编的,但没有播放。花了一些时间浏览论坛,但似乎没有任何东西可以解决它。
我有两种方法。第一个调用标准打开文件对话框,打开音频文件,分配一个AVAudioBuffer对象(我将在稍后使用)并用音频数据填充它。第二个设置AVAudioEngine和AVAudioPlayerNode对象,连接所有内容并播放文件。下面列出了这两种方法。
- (IBAction)getSoundFileAudioData:(id)sender {
NSOpenPanel* openPanel = [NSOpenPanel openPanel];
openPanel.title = @"Choose a .caf file";
openPanel.showsResizeIndicator = YES;
openPanel.showsHiddenFiles = NO;
openPanel.canChooseDirectories = NO;
openPanel.canCreateDirectories = YES;
openPanel.allowsMultipleSelection = NO;
openPanel.allowedFileTypes = @[@"caf"];
[openPanel beginWithCompletionHandler:^(NSInteger result){
if (result == NSFileHandlingPanelOKButton) {
NSURL* theAudioFileURL = [[openPanel URLs] objectAtIndex:0];
// Open the document.
theAudioFile = [[AVAudioFile alloc] initForReading:theAudioFileURL error:nil];
AVAudioFormat *format = theAudioFile.processingFormat;
AVAudioFrameCount capacity = (AVAudioFrameCount)theAudioFile.length;
theAudioBuffer = [[AVAudioPCMBuffer alloc]
initWithPCMFormat:format frameCapacity:capacity];
NSError *error;
if (![theAudioFile readIntoBuffer:theAudioBuffer error:&error]) {
NSLog(@"problem filling buffer");
}
else
playOrigSoundFileButton.enabled = true;
}
}];}
- (IBAction)playSoundFileAudioData:(id)sender {
AVAudioEngine *engine = [[AVAudioEngine alloc] init]; // set up the audio engine
AVAudioPlayerNode *player = [[AVAudioPlayerNode alloc] init]; // set up a player node
[engine attachNode:player]; // attach player node to engine
AVAudioMixerNode *mixer = [engine mainMixerNode];
[engine connect:player to:mixer format:theAudioFile.processingFormat]; // connect player node to mixer
[engine connect:player to:mixer format:[mixer outputFormatForBus:0]]; // connect player node to mixer
NSError *error;
if (![engine startAndReturnError:&error]) {
NSLog(@"Problem starting engine ");
}
else {
[player scheduleFile:theAudioFile atTime: nil completionHandler:nil];
[player play];
}
}
我已检查过正在执行的功能,音频引擎是否正在运行以及是否已读取音频文件。我也试过不同的音频文件格式,包括单声道和立体声。有什么想法吗?
我正在运行Xcode 7.3.1。
答案 0 :(得分:4)
将您的AVAudioPlayerNode *player
声明为全球