Filter rgbtestsrc
  Generate RGB test pattern.
    Inputs:
        none (source filter)
    Outputs:
       #0: default (video)
rgbtestsrc AVOptions:
  size              <image_size> ..FV..... set video size (default "320x240")
  s                 <image_size> ..FV..... set video size (default "320x240")
  rate              <video_rate> ..FV..... set video rate (default "25")
  r                 <video_rate> ..FV..... set video rate (default "25")
  duration          <duration>   ..FV..... set video duration (default -0.000001)
  d                 <duration>   ..FV..... set video duration (default -0.000001)
  sar               <rational>   ..FV..... set video sample aspect ratio (from 0 to INT_MAX) (default 1/1)


