Amplify

Amplify(clip, float amount1 [, ...])
Amplify(clip, float left, float right)
AmplifydB(clip, float amount1 [, ...])
AmplifydB(clip, float left, float right)

These filters amplify the audio of the clip by the prescribed amount.

Amplify multiplies the audio samples by amount. You use scale factors between 0 and 1 for reducing volume.

• Negative scale factors will shift the phase by 180 degrees (i.e. invert the samples)

AmplifyDB is the same, except values are in decibels (dB). The relation between them is 'amount = 10^(decibels/20)'. You use negative dB values for reducing volume.

• AmplifyDB( 6.0) is equivalent to Amplify(2.0)
• AmplifyDB( 0.0) is equivalent to Amplify(1.0)
• AmplifyDB(-6.0) is equivalent to Amplify(0.5)

You can specify different factors for each channel. If there are more volumes than there are channels, the extra volume arguments are ignored. If there are fewer volumes than channels, the last volume is applied to the rest of the channels.

8bit and 24bit Audio samples are converted to float in the process, the other audio formats are kept.