code: public T setVideoResolution(String abbreviation) {
      this.video_enabled = true;
      this.video_size = checkNotEmpty(abbreviation, "video abbreviation must not be empty");
      return getThis();
    }
docs: Sets video resolution based on an abbreviation, e.g. "ntsc" for 720x480, or "vga" for 640x480
  
  @see <a href="https://www.ffmpeg.org/ffmpeg-utils.html#Video-size">ffmpeg video size</a>
  @param abbreviation The abbreviation size. No validation is done, instead the value is passed
  as is to ffmpeg.
  @return this