Encoder Options for SPX Files

SPX (.spx) is the extension of Speex files. The Speex codec is designed primarily for speech encoding.

Quality Options

Use Quality Preset - This option specifies an overall quality. The encoder will choose its bitrate based on the selection you provide in the pulldown list (level 8 is the default setting). Use this option if you do not need specific control over how the file is encoded.

Enable Constant Bitrate (CBR) - Use this option if you would like to instruct the encoder to use your specified bitrate for the entire conversion.

Enable Variable Bitrate (VBR) -Variable bitrate encoding allows the encoder to change the bitrate it is using depending on the nature of the audio data. Some types of audio data can withstand greater levels of compression than other types. Choosing this option will generally yield smaller files and arguably similar quality compared to constant bitrate encodings. Simply specify the maximum bitrate you want to allow the encoder to use.

Enable Average Bitrate (ABR) - Average bitrate encoding allows the encoder some flexibility to change the bitrate while still maintaining the specified average bitrate.

Extra Processing Options

Apply adaptive gain control - If you have a recording which is particularly high or low in volume this setting will instruct the encoder to adjust the signal to a reference volume.

Denoise input before encoding - Check this setting if the target of your recording (such as speech) is suffering from noise interference. The encoder will attempt to remove this noise before encoding to your chosen format.