iOS-AVAudioRecorder-使用ADPCM或IMA錄制

Question

使用這些錄制設置，我可以使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;
}

一旦我更改此：

[NSNumber numberWithInt:kAudioFormatLinearPCM],AVFormatIDKey,

對此：

[NSNumber numberWithInt:kAudioFormatAppleIMA4],AVFormatIDKey,

我收到以下錯誤：

recorder: NSOSStatusErrorDomain 1718449215 {
}

也就是說，不支持音頻格式。 kAudioFormatUnsupportedDataFormatError

我需要怎么做才能使ADPCM或IMA與AVAudioRecorder一起使用？

Answer 1

1）請確保您為錄制（或）回放（或）兩者（即VOIP）正確設置了會話，如下所示：

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

2）使用以下代碼，因為這對我來說很好用（由於我有消息傳遞應用程序，因此壓縮為低質量）：

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
                               ];

問候海德·薩蒂