Apply spectral dynamic range controller filter to input audio stream.
A description of the accepted options follows.
- transfer
-
Set the transfer expression.
The expression can contain the following constants:
- ch
-
current channel number
- sn
-
current sample number
- nb_channels
-
number of channels
- t
-
timestamp expressed in seconds
- sr
-
sample rate
- p
-
current frequency power value, in dB
- f
-
current frequency in Hz
Default value is
p. - attack
-
Set the attack in milliseconds. Default is
50milliseconds. Allowed range is from 1 to 1000 milliseconds. - release
-
Set the release in milliseconds. Default is
100milliseconds. Allowed range is from 5 to 2000 milliseconds. - channels
-
Set which channels to filter, by default
allchannels in audio stream are filtered.
Commands
This filter supports the all above options as commands.
Examples
-
Apply spectral compression to all frequencies with threshold of -50 dB and 1:6 ratio:
adrc=transfer='if(gt(p,-50),-50+(p-(-50))/6,p)':attack=50:release=100
-
Similar to above but with 1:2 ratio and filtering only front center channel:
adrc=transfer='if(gt(p,-50),-50+(p-(-50))/2,p)':attack=50:release=100:channels=FC
-
Apply spectral noise gate to all frequencies with threshold of -85 dB and with short attack time and short release time:
adrc=transfer='if(lte(p,-85),p-800,p)':attack=1:release=5
-
Apply spectral expansion to all frequencies with threshold of -10 dB and 1:2 ratio:
adrc=transfer='if(lt(p,-10),-10+(p-(-10))*2,p)':attack=50:release=100
-
Apply limiter to max -60 dB to all frequencies, with attack of 2 ms and release of 10 ms:
adrc=transfer='min(p,-60)':attack=2:release=10