iphone：AVAudioRecorder 录音总是返回 FALSE

Question

I am using AVAudioRecorder to record sound, but I have a problem.

After calling the method [recorder record], the value of recorder.recording always returns FALSE, so that I can not stop the recording.

I am using XCode 4.2 with iOS 5, my iPad is ipad 2 on iOS 5 also.

This is my code:

    self.currentFileName = [GlobalRecording newRecordingFileName];
    NSURL *url = [NSURL fileURLWithPath:[[GlobalRecording recordingDirectory]    stringByAppendingPathComponent:currentFileName]];
NSError *err = nil;

AVAudioRecorder *aRecorder = [[AVAudioRecorder alloc] initWithURL:url settings:recordingSettings error:&err];
if( err ){
    NSLog(@"could not create a recorder: %@ %d %@", [err domain], [err code], [[err userInfo] description]);
    return;
}

self.startRecordingTime = [NSDate date];
recordingLength = 0.0f;

//  setup recorder and start recording
[aRecorder setDelegate:self];
aRecorder.meteringEnabled = YES;
[aRecorder record];

self.recorder = aRecorder;
BOOL test = recorder.recording;
[aRecorder release];

Answer 1

try using AVAudioSession after [audioRecord prepareToRecord]

    NSError *err = nil;
audioSession = [AVAudioSession sharedInstance];
[audioSession setCategory :AVAudioSessionCategoryPlayAndRecord error:&err];

// route to speaker
UInt32 ASRoute = kAudioSessionOverrideAudioRoute_Speaker;
AudioSessionSetProperty(kAudioSessionProperty_OverrideAudioRoute, sizeof(ASRoute), &ASRoute);

if (err)
{
    NSLog(@"audioSession: %@ %d %@", [err domain], [err code], [[err userInfo] description]);
}

[audioSession setActive:YES error:&err];

Answer 2

An audio session is the intermediary between your app and iOS used to configure your app's audio behavior. Upon launch, your app automatically gets a singleton audio session.

so activate your session before start recording

For Swift 3.0

let session = AVAudioSession.sharedInstance()
        do {
            try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
        } catch let error as NSError {
            print("could not set session category")
            print(error.localizedDescription)
        }
        do {
            try session.setActive(true)
        } catch let error as NSError
        {
            print("could not make session active")
            print(error.localizedDescription)
        }
self.recorder.record() // recorder is my AVAudioRecorder

Answer 3

I had a similar symptom, because I was using a library to playback that was resetting AVAudioSession global settings. I needed to reset the settings each time I wanted to record.

do {
  try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
  try session.setActive(true)
} catch {
  return error
}

The library I'm using resets it to AVAudioSessionCategoryPlay . Sure would be nice if there was an error to access other than false to let you know what caused the failure of record() .

Answer 4

I encountered the same problem on Simulator, and after investigation I found that it was because my computer didn't set up any audio input sources. Once I connected an input source (eg, AirPod) and record() finally returned true and started to work. Sadly, record() never gives any error to indicate this type of failure.

Answer 5

Are you also seeing a delay when you invoke the record method? I'm seeing an issue when using iOS5 on iPhone4 hardware where the record method has a 3-4 second delay and occasionally will fail to start recording. I'm calling prepareToRecord as recommended with the same issue.

This is not an issue on iOS4/iPhone4 or iOS5/iPhone4S...so it seems to be an issue running the new OS on older hardware.