Since*
1.0
Adjust audio tempo.
The filter accepts exactly one parameter, the audio tempo. If not specified then the filter will assume nominal 1.0 tempo. Tempo must be in the [0.5, 2.0] range.
Examples
-
Slow down audio to 80% tempo:
atempo=0.8
-
To speed up audio to 125% tempo:
atempo=1.25