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# Bit Rate Control Mode Constants

Bit rate control modes to be used with `kAudioCodecPropertyBitRateControlMode`.

## Discussion

These modes are applicable only to encoders that can produce variable packet sizes, such as AAC.

## Topics

### Constants

[`var kAudioCodecBitRateControlMode_Constant: UInt32`](/documentation/AudioToolbox/kAudioCodecBitRateControlMode_Constant)

[`var kAudioCodecBitRateControlMode_LongTermAverage: UInt32`](/documentation/AudioToolbox/kAudioCodecBitRateControlMode_LongTermAverage)

[`var kAudioCodecBitRateControlMode_Variable: UInt32`](/documentation/AudioToolbox/kAudioCodecBitRateControlMode_Variable)

[`var kAudioCodecBitRateControlMode_VariableConstrained: UInt32`](/documentation/AudioToolbox/kAudioCodecBitRateControlMode_VariableConstrained)


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