Amplify / AmplifydB¶
Amplify and AmplifydB amplify the audio of the clip by the prescribed amount. You can specify different amount arguments for each channel. If there are more arguments than there are channels, the extra ones are ignored. If there are fewer arguments than channels, the last one is applied to the rest of the channels.
Amplify¶
Amplify the audio in linear values. See the Examples section for more information.
Syntax and Parameters
Amplify (clip, float amount [, float amount ]...)
- clip
- Source clip. Supported audio sample types: 16/32-bit integer, and 32-bit float.Other sample types (8 and 24-bit integer) are automatically converted to 32-bit float.
- amount
Multiply (scale) the audio by
amount
; values are linear:amount
> 1.0 increases volumeamount
< 1.0 decreases volumeamount
= 1.0 retains the same volumeNegative scale factors will shift the phase by 180 degrees (i.e. invert the samples).
AmplifydB¶
Amplify the audio in decibels. See the Examples section for more information.
Syntax and Parameters
AmplifydB (clip, float amount [, float amount ]...)
- clip
- Source clip. Supported audio sample types: 16/32-bit integer, and 32-bit float.Other sample types (8 and 24-bit integer) are automatically converted to 32-bit float.
- amount
Multiply (scale) the audio by
amount
; values are in dB (decibels):amount
> 0.0 increases volumeamount
< 0.0 decreases volumeamount
= 0.0 retains the same volume
Examples¶
The relation between linear and decibel gain control is:
lin = 10 (dB/20)
dB = 20·log10 (lin)
For example,
AmplifydB( 0.0)
is equivalent toAmplify(1.0)
(no change)AmplifydB( 6.0)
is equivalent toAmplify(2.0)
(about twice as loud)AmplifydB( -6.0)
is equivalent toAmplify(0.5)
(about half as loud)AmplifydB( 20.0)
is equivalent toAmplify(10)
(much louder)AmplifydB(-20.0)
is equivalent toAmplify(0.1)
(much softer)
More examples:
AmplifydB(+3, 0)
increases the volume of the left channel by a small amount.Amplify(-1, 1)
inverts the phase of the left channel. See Wikipedia: Out Of Phase Stereo.
See Also
Normalize - with show=true, can show the maximum amplification possible without clipping.
How the multichannels are mapped can be found in the description of GetChannel.
Changelog¶
Version |
Changes |
---|---|
AviSynth 2.5.7 |
Fixed a small memory leak in Amplify(). |
AviSynth 1.0.0 |
Added Amplify and AmplifydB filters. |
$Date: 2022/03/05 15:10:22 $