Encoder ac3_fixed [ATSC A/52A (AC-3)]:
    Supported sample formats: s16p
    Supported channel layouts: mono stereo 3.0(back) 3.0 quad(side) quad 4.0 5.0(side) 5.0 2 channels (FC+LFE) 2.1 4 channels (FL+FR+LFE+BC) 3.1 5 channels (FL+FR+LFE+SL+SR) 5 channels (FL+FR+LFE+BL+BR) 4.1 5.1(side) 5.1
Fixed-Point AC-3 Encoder AVOptions:
  -per_frame_metadata <int>        E...A. Allow Changing Metadata Per-Frame (from 0 to 1)
  -center_mixlev     <float>      E...A. Center Mix Level (from 0 to 1)
  -surround_mixlev   <float>      E...A. Surround Mix Level (from 0 to 1)
  -mixing_level      <int>        E...A. Mixing Level (from -1 to 111)
  -room_type         <int>        E...A. Room Type (from -1 to 2)
     notindicated                 E...A. Not Indicated (default)
     large                        E...A. Large Room
     small                        E...A. Small Room
  -copyright         <int>        E...A. Copyright Bit (from -1 to 1)
  -dialnorm          <int>        E...A. Dialogue Level (dB) (from -31 to -1)
  -dsur_mode         <int>        E...A. Dolby Surround Mode (from -1 to 2)
     notindicated                 E...A. Not Indicated (default)
     on                           E...A. Dolby Surround Encoded
     off                          E...A. Not Dolby Surround Encoded
  -original          <int>        E...A. Original Bit Stream (from -1 to 1)
  -dmix_mode         <int>        E...A. Preferred Stereo Downmix Mode (from -1 to 2)
     notindicated                 E...A. Not Indicated (default)
     ltrt                         E...A. Lt/Rt Downmix Preferred
     loro                         E...A. Lo/Ro Downmix Preferred
  -ltrt_cmixlev      <float>      E...A. Lt/Rt Center Mix Level (from -1 to 2)
  -ltrt_surmixlev    <float>      E...A. Lt/Rt Surround Mix Level (from -1 to 2)
  -loro_cmixlev      <float>      E...A. Lo/Ro Center Mix Level (from -1 to 2)
  -loro_surmixlev    <float>      E...A. Lo/Ro Surround Mix Level (from -1 to 2)
  -dsurex_mode       <int>        E...A. Dolby Surround EX Mode (from -1 to 2)
     notindicated                 E...A. Not Indicated (default)
     on                           E...A. Dolby Surround EX Encoded
     off                          E...A. Not Dolby Surround EX Encoded
  -dheadphone_mode   <int>        E...A. Dolby Headphone Mode (from -1 to 2)
     notindicated                 E...A. Not Indicated (default)
     on                           E...A. Dolby Headphone Encoded
     off                          E...A. Not Dolby Headphone Encoded
  -ad_conv_type      <int>        E...A. A/D Converter Type (from -1 to 1)
     standard                     E...A. Standard (default)
     hdcd                         E...A. HDCD
  -stereo_rematrixing <int>        E...A. Stereo Rematrixing (from 0 to 1)
  -channel_coupling  <int>        E...A. Channel Coupling (from -1 to 1)
     auto                         E...A. Selected by the Encoder
  -cpl_start_band    <int>        E...A. Coupling Start Band (from -1 to 15)
     auto                         E...A. Selected by the Encoder

