当我们录制音频时,如何将音频录制设置更改为16Khz和16位?

我的设置如下所示。

我想在录制音频时将音频录制设置更改为16Khz和16位。

NSArray *dirPaths;
NSString *docsDir;

dirPaths = NSSearchPathForDirectoriesInDomains(
                                               NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
NSString *soundFilePath = [docsDir
                           stringByAppendingPathComponent:@"sound.wav"];

NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath];

NSDictionary *recordSettings = [NSDictionary
                                dictionaryWithObjectsAndKeys:
                                [NSNumber numberWithInt:AVAudioQualityMin],
                                AVEncoderAudioQualityKey,
                                [NSNumber numberWithInt:16],
                                AVEncoderBitRateKey,
                                [NSNumber numberWithInt: 2],
                                AVNumberOfChannelsKey,
                                [NSNumber numberWithFloat:44100.0],
                                AVSampleRateKey,
                                nil];

NSError *error = nil;

audioRecorder = [[AVAudioRecorder alloc]
                 initWithURL:soundFileURL
                 settings:recordSettings
                 error:&error];

if (error)
{

} else
{
    [audioRecorder prepareToRecord];
}

如何设置这些设置?

编辑问题 :

感谢您的回复,我尝试了这些方法,但对我来说不起作用,因为我的客户正在将录制的语音(我以字节格式发送的录制语音)发送到ASR引擎(自动语音识别)。我没有收到我发送的相同的回复(我收到的回复音频上写着“引号”)。客户说你没有以16KHz和16位采样率录制语音,这就是为什么你会得到这样的回应。但我问他我发送给他的服务器的字节数,他给出了.wav文件,它播放得很好。但是,如果他发送给ASR引擎的是同一个,ASR引擎不会接受我发送的录音(他说ASR不会接受,因为你没有以16KHz和16位采样率录制音频)。客户给出了以下回应。(但是,我尝试了你建议的所有方法)

Filename:   sv_SE_356985580762248932.wav
Folder: E:\developApp\TestappName\Mortionsn_dev\2nd-iteration\test_wfiles
File Type:  44100Hz, 16-bit, Stereo
Uncompressed Size:  1.63 MB (1,713,696 bytes)
File Format:    Windows PCM
Windows PCM
Size on Disk:   1.63 MB (1,717,892 bytes)
Last Written (local):   3/11/2013  00:21:00.000
Length: 0:09.714
428,424 samples

使用以下答案第二次编辑问题 :

后来,通过给出建议,我将设置代码更改为:

NSMutableDictionary *recordSettings = [NSMutableDictionary dictionary];


[recordSettings setValue: [NSNumber numberWithInt:kAudioFormatLinearPCM] forKey:AVFormatIDKey];

[recordSettings setValue: [NSNumber numberWithFloat:16000.0] forKey:AVSampleRateKey];//8000.0

[recordSettings setValue: [NSNumber numberWithInt: 1] forKey:AVNumberOfChannelsKey];

[recordSettings setValue: [NSNumber numberWithInt:16] forKey:AVLinearPCMBitDepthKey];

[recordSettings setValue: [NSNumber numberWithBool:NO] forKey:AVLinearPCMIsBigEndianKey];

[recordSettings setValue: [NSNumber numberWithBool:NO] forKey:AVLinearPCMIsFloatKey];

[recordSettings setValue: [NSNumber numberWithInt: AVAudioQualityMax] forKey:AVEncoderAudioQualityKey];