Filter abench
  Benchmark part of a filtergraph.
    Inputs:
       #0: default (audio)
    Outputs:
       #0: default (audio)
abench AVOptions:
  action            <int>        ..F.A...... set action (from 0 to 1) (default start)
     start           0            ..F.A...... start timer
     stop            1            ..F.A...... stop timer


