Question

我正在成功使用RemoteIO对来自麦克风的传入音频流进行分析。但是我似乎无法将文件写入磁盘。我已经阅读了很多问题：

并尝试在那里实施建议：除非他们不工作。哪里是调用ExtAudioFileWriteAsync的正确位置，我该如何设置它？

Answer 1

除了（相当艰巨但更好地涵盖Apple's example code）RemoteIO本身的设置过程之外，关键点是：

首先使用我用来设置流的AudioStreamBasicDescription（*audioFormat）。根据其他问题和帖子，我不知道我花了多长时间尝试建立一个参数略有不同的新参数。只需从我的ivar引用流属性就足够了。
设置“isRecording”bool，以便您可以打开和关闭写入文件，而无需拆除和重新设置RemoteIO会话
可以写入recordingCallback，嗯，回调中的文件，但是异步执行。很多信息都谈到在playbackCallback中做这件事或设置第三个audioFileWriteCallback。这导致了无声文件或4KB（即空）文件。不要这样做。
另外，请务必使用传递给回调的ioData的副本

recordingCallback

AudioUnitRender

bufferList

：

    AudioDeviceManager* THIS = (__bridge AudioDeviceManager *)inRefCon;
    if (THIS->isRecording) {
      ExtAudioFileWriteAsync(THIS->extAudioFileRef, inNumberFrames, bufferList);
    }

启动和停止录制功能，供参考：

-(void)startRecording {



  NSArray  *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString *documentsDirectory = [paths objectAtIndex:0];
  NSString *destinationFilePath = [documentsDirectory stringByAppendingPathComponent:kAudioFileName];
  CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)destinationFilePath, kCFURLPOSIXPathStyle, false);

  OSStatus status;

  // create the capture file
  status = ExtAudioFileCreateWithURL(destinationURL, kAudioFileWAVEType, &audioFormat, NULL, kAudioFileFlags_EraseFile, &extAudioFileRef);
  if (status) NSLog(@"Error creating file with URL: %ld", status);

 // use the same "audioFormat" AudioStreamBasicDescription we used to set up RemoteIO in the first place
  status = ExtAudioFileSetProperty(extAudioFileRef, kExtAudioFileProperty_ClientDataFormat, sizeof(AudioStreamBasicDescription), &audioFormat);

  ExtAudioFileSeek(extAudioFileRef, 0);
  ExtAudioFileWrite(extAudioFileRef, 0, NULL);

  isRecording = YES;
}

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSString *destinationFilePath = [documentsDirectory stringByAppendingPathComponent:kAudioFileName]; CFURLRef destinationURL = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (CFStringRef)destinationFilePath, kCFURLPOSIXPathStyle, false); OSStatus status; // create the capture file status = ExtAudioFileCreateWithURL(destinationURL, kAudioFileWAVEType, &audioFormat, NULL, kAudioFileFlags_EraseFile, &extAudioFileRef); if (status) NSLog(@"Error creating file with URL: %ld", status); // use the same "audioFormat" AudioStreamBasicDescription we used to set up RemoteIO in the first place status = ExtAudioFileSetProperty(extAudioFileRef, kExtAudioFileProperty_ClientDataFormat, sizeof(AudioStreamBasicDescription), &audioFormat); ExtAudioFileSeek(extAudioFileRef, 0); ExtAudioFileWrite(extAudioFileRef, 0, NULL); isRecording = YES; }

就是这样！

RemoteIO录制的音频文件是静音或4KB

1 个答案: