IPhone之AVAudioRecorder

    NSMutableDictionary *recordSettings =         [[NSMutableDictionary alloc] initWithCapacity:10];         //1 ID号         [recordSettings setObject:          [NSNumber numberWithInt: kAudioFormatLinearPCM] forKey: AVFormatIDKey];         float sampleRate =          [pcmSettingsViewController.sampleRateField.text floatValue];         //2 采样率         [recordSettings setObject:          [NSNumber numberWithFloat:sampleRate] forKey: AVSampleRateKey];                   //3 通道的数目         [recordSettings setObject:          [NSNumber numberWithInt:           (pcmSettingsViewController.stereoSwitch.on ? 2 : 1)]          forKey:AVNumberOfChannelsKey];         int bitDepth =          [pcmSettingsViewController.sampleDepthField.text intValue];                   //4 采样位数  默认 16         [recordSettings setObject:          [NSNumber numberWithInt:bitDepth] forKey:AVLinearPCMBitDepthKey];                   //5         [recordSettings setObject:          [NSNumber numberWithBool:            pcmSettingsViewController.bigEndianSwitch.on]           forKey:AVLinearPCMIsBigEndianKey];                 //6 采样信号是整数还是浮点数         [recordSettings setObject:          [NSNumber numberWithBool:            pcmSettingsViewController.floatingSamplesSwitch.on]           forKey:AVLinearPCMIsFloatKey]     ;