iOS - AVAudioRecorder -使用ADPCM或IMA录制

Question

通过使用这些录制设置，我可以让AVAudioRecorder正常工作：

    recordSetting = [NSDictionary dictionaryWithObjectsAndKeys:
//                     [NSNumber numberWithFloat:2048.0f],AVSampleRateKey,
//                     [NSNumber numberWithInt:1],AVNumberOfChannelsKey,
//                     [NSNumber numberWithInt:8],AVLinearPCMBitDepthKey,
                     [NSNumber numberWithInt:kAudioFormatLinearPCM],AVFormatIDKey,
//                     [NSNumber numberWithBool:NO], AVLinearPCMIsFloatKey,
//                     [NSNumber numberWithBool:0], AVLinearPCMIsBigEndianKey,
//                     [NSNumber numberWithBool:NO], AVLinearPCMIsNonInterleaved,
//                     [NSNumber numberWithInt:256], AVEncoderBitRateKey,
                     [NSData data], AVChannelLayoutKey, nil];


recorder = [[ AVAudioRecorder alloc] initWithURL:url settings:recordSetting error:&err];


if(!recorder){
    NSLog(@"recorder: %@ %d %@", [err domain], [err code], [[err userInfo] description]);
    UIAlertView *alert =
    [[UIAlertView alloc] initWithTitle: @"Warning"
                               message: [err localizedDescription]
                              delegate: nil
                     cancelButtonTitle:@"OK"
                     otherButtonTitles:nil];
    [alert show];

    return;
}

一旦我改变了这个：

[NSNumber numberWithInt:kAudioFormatLinearPCM],AVFormatIDKey,

要这样做：

[NSNumber numberWithInt:kAudioFormatAppleIMA4],AVFormatIDKey,

我得到以下错误：

recorder: NSOSStatusErrorDomain 1718449215 {
}

也就是说，不支持音频格式。kAudioFormatUnsupportedDataFormatError

我需要做什么才能让ADPCM或IMA与AVAudioRecorder协同工作？

Answer 1

1)请确保您正确设置了录制(或)播放(或)两者(即VOIP)的会话，如下所示：

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryRecord error:nil];

2)使用以下代码，因为这对我很有效(我压缩到低质量，因为我有一个消息应用程序)：

NSDictionary *AudioSettings = [[NSDictionary alloc] initWithObjectsAndKeys:
                               [NSNumber numberWithInt:kAudioFormatAppleIMA4], AVFormatIDKey
                               , [NSNumber numberWithFloat:11025.00], AVSampleRateKey
                               , [NSNumber numberWithInt:1], AVNumberOfChannelsKey
                               , [NSNumber numberWithInt:11025], AVEncoderBitRateKey
                               , [NSNumber numberWithInt:8], AVLinearPCMBitDepthKey
                               , [NSNumber numberWithInt:AVAudioQualityMin], AVEncoderAudioQualityKey
                               , [NSNumber numberWithInt:1], AVNumberOfChannelsKey
                               , nil
                               ];

致敬Heider Sati