Encoder libxavs [libxavs Chinese AVS (Audio Video Standard)]:
    Threading capabilities: no
    Supported pixel formats: yuv420p
libxavs AVOptions:
-crf               <float>      E..V.. Select the quality for constant quality mode (from -1 to FLT_MAX)
-qp                <int>        E..V.. Constant quantization parameter rate control method (from -1 to INT_MAX)
-b-bias            <int>        E..V.. Influences how often B-frames are used (from INT_MIN to INT_MAX)
-cplxblur          <float>      E..V.. Reduce fluctuations in QP (before curve compression) (from -1 to FLT_MAX)
-direct-pred       <int>        E..V.. Direct MV prediction mode (from -1 to INT_MAX)
   none                         E..V..
   spatial                      E..V..
   temporal                     E..V..
   auto                         E..V..
-aud               <int>        E..V.. Use access unit delimiters. (from -1 to 1)
-mbtree            <int>        E..V.. Use macroblock tree ratecontrol. (from -1 to 1)
-mixed-refs        <int>        E..V.. One reference per partition, as opposed to one reference per macroblock (from -1 to 1)
-fast-pskip        <int>        E..V.. (from -1 to 1)

