Nero Burning ROM

Drop-down menu Constant Bit Rate

Selects a constant bit rate, i.e. the data flow per unit of time and the quality of the saved data are the same over the entire audio file. If the bit rate is small, less data is transferred. The file is then small, but quality is lower. If the bit rate is high, more data is transferred. The file size is then large, but the quality is high. The default value of 128 for MP3 files is near CD quality.

Drop-down menu Variable Bit Rate

Selects variable bit rate, i.e. the data flow per unit of time – and thus the quantity of the saved data – adapts to the dynamics of the audio file. The bit rate, for example, can be lowered at quieter points in the track. Select your desired quality level in the drop-down menu.

Drop-down menu Encoding quality	Specifies the encoder quality. These settings specify whether you place more value on fast encoding (lowest/fastest) or more value on a superior psychoacoustic encoder model for the very best results (highest/slowest).
Check box Original bit	Sets the original bit in the music file, which differentiates between the copy and the original. Check box selected: Original bit = 1, i.e. original. Check box cleared: Original bit = 0, i.e. copy.
Check box Private bit	Sets the private bit in the music file. It is reserved for the user and is only used for informational purposes.
Check box Copyright bit	Sets the copyright bit in the music file, which identifies protected content. Check box selected: Copyright bit = 1, i.e. protected. Check box cleared: Copyright bit = 0, i.e. unprotected.
Check box Write CRC	Also sets a checksum in the music file to ensure that transfer errors are detected.

MP3

The MPEG-1 Audio Layer 3 audio format is used to reduce the size of audio files to a fraction of their original size (factor 1:10) with little loss of quality. You can estimate about 1 MB per minute as opposed to 10 MB for the original files. This value and the quality can vary depending on the complexity of the audio signal. The bit rate used can be used as a measure of quality. The higher the bit rate, the better the quality, but also the more memory required.

Codec

The compressor/decompressor encodes the data for recording or saving digitally and then decodes it for playback. Various software codecs are available such as Cinapak, Indeo, Quicktime, Video for Windows, etc. Hardware codecs include MPEG, H.261, Motion JPEG, etc.