ios - AVAudioRecorder - 如何从来电中恢复
<p><p>我正在尝试实现一些我认为非常容易的事情，但事实证明并非如此。</p>
<p>我正在使用“react-native-audio”库的源代码。但是你可以假设我为了这个问题而在本地工作。 </p>
<p>这里是 <a href="https://github.com/jsierles/react-native-audio/blob/master/ios/AudioRecorderManager.m" rel="noreferrer noopener nofollow">reference for the source code</a>我在玩。</p>
<p>我的目标很简单，我正在使用 <code>AVAudioRecorder</code> 录制 session (大约需要 30 分钟)。如果在录音过程中有来电，我希望我的应用能够通过执行以下选项之一“恢复”:</p>
<p>1) 当应用回到前台时，“暂停”“来电”和“恢复”记录。</p>
<p>2) 来电时 - 关闭当前文件，当应用程序返回前台时，开始使用新文件进行新录制(第 2 部分)。 </p>
<p>显然选项 (1) 是首选。</p>
<p>请注意，我很清楚使用 <code>AVAudioSessionInterruptionNotification</code> 并在我的实验中使用它到目前为止没有运气，例如:</p>
<pre><code>- (void) receiveAudioSessionNotification:(NSNotification *) notification
{
if () {
NSLog(@"AVAudioSessionInterruptionNotification");
NSNumber *type = ;
if (]) {
NSLog(@"*** InterruptionTypeBegan");
;
} else {
NSLog(@"*** InterruptionTypeEnded");
;
}
}
}
</code></pre>
<p>请注意，我将为这个问题设置赏金，但唯一可接受的答案将是真实世界的工作代码，而不是“理论上应该工作”的东西。非常感谢您的帮助:)</p></p>
<br><hr><h1><strong>Best Answer-推荐答案</ strong></h1><br>
<p><p>我选择<code>AVAudioEngine</code>和<code>AVAudioFile</code>作为解决方案，因为代码很简短，AVFoundation的中断处理是<a href="https://developer.apple.com/library/archive/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/HandlingAudioInterruptions/HandlingAudioInterruptions.html" rel="noreferrer noopener nofollow">particularly simple</a> (您的播放器/录音机对象已暂停，取消暂停会重新激活您的 Audio Session )。</p>
<p><strong>N.B</strong> <code>AVAudioFile</code> 没有明确的关闭方法，而是在 <code>dealloc</code> 期间写入标题并关闭文件，令人遗憾的是，这种选择会使内容复杂化否则将是一个简单的 API。</p>
<pre><code>@interface ViewController ()
@property (nonatomic) AVAudioEngine *audioEngine;
@property AVAudioFile *outputFile;
@end
@implementation ViewController
- (void)viewDidLoad {
;
AVAudioSession *session = ;
NSError *error;
if (!){
NSLog(@"Failed to set session category: %@", error);
}
[ addObserver:self selector:@selector(audioInterruptionHandler:) name:AVAudioSessionInterruptionNotification object:nil];
NSURL *outputURL = [[ URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] URLByAppendingPathComponent:@"output.aac"];
__block BOOL outputFileInited = NO;
self.audioEngine = [ init];
AVAudioInputNode *inputNode = self.audioEngine.inputNode;
[inputNode installTapOnBus:0 bufferSize:512 format:nil block:^(AVAudioPCMBuffer *buffer, AVAudioTime * when) {
NSError *error;
if (self.outputFile == nil && !outputFileInited) {
NSDictionary *settings = @{
AVFormatIDKey: @(kAudioFormatMPEG4AAC),
AVNumberOfChannelsKey: @(buffer.format.channelCount),
AVSampleRateKey: @(buffer.format.sampleRate)
};
self.outputFile = [ initForWriting:outputURL settings:settings error:&error];
if (!self.outputFile) {
NSLog(@"output file error: %@", error);
abort();
}
outputFileInited = YES;
}
if (self.outputFile && !) {
NSLog(@"AVAudioFile write error: %@", error);
}
}];
if (!) {
NSLog(@"engine start error: %@", error);
}
// To stop recording, nil the outputFile at some point in the future.
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(20 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
NSLog(@"Finished");
self.outputFile = nil;
});
}
// https://developer.apple.com/library/archive/documentation/Audio/Conceptual/AudioSessionProgrammingGuide/HandlingAudioInterruptions/HandlingAudioInterruptions.html
- (void)audioInterruptionHandler:(NSNotification *)notification {
NSDictionary *info = notification.userInfo;
AVAudioSessionInterruptionType type = unsignedIntegerValue];
switch (type) {
case AVAudioSessionInterruptionTypeBegan:
NSLog(@"Begin interruption");
break;
case AVAudioSessionInterruptionTypeEnded:
NSLog(@"End interruption");
// or ignore shouldResume if you're really keen to resume recording
AVAudioSessionInterruptionOptions endOptions = unsignedIntegerValue];
if (AVAudioSessionInterruptionOptionShouldResume == endOptions) {
NSError *error;
if (!) {
NSLog(@"Error restarting engine: %@", error);
}
}
break;
}
}
@end
</code></pre>
<p>注意您可能想要启用背景音频(当然，在 Info.plist 中添加 <code>NSMicrophoneUsageDescription</code> 字符串)。 </p></p>
<p style="font-size: 20px;">关于ios - AVAudioRecorder - 如何从来电中恢复，我们在Stack Overflow上找到一个类似的问题：
<a href="https://stackoverflow.com/questions/54169447/" rel="noreferrer noopener nofollow" style="color: red;">
https://stackoverflow.com/questions/54169447/
</a>
</p>
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