Encoder libopencore_amrnb [OpenCORE AMR-NB (Adaptive Multi-Rate Narrow-Band)]:
    General capabilities: delay small 
    Threading capabilities: none
    Supported sample formats: s16
libopencore_amrnb AVOptions:
  -dtx               <int>        E...A.... Allow DTX (generate comfort noise) (from 0 to 1) (default 0)


