Softron's OnTheAir Video Express 4 (Electronic Download) is a Mac-based, 64-bit playout software with flexible playlist support.

In OnTheAir Video Express 4, Softron uses its own playout engine called Smart Playout Engine. This player allows mixing multiple codecs and resolutions in the same playlist without installing any additional software, and it features an Automatic Resize tool that will efficiently scale frame sizes to Fill, Pan-and-Scan, or Letterbox.

The standard playout file type is QuickTime (.mov), but you can also select Transport Stream (.ts), MXF (.MXF), and others. Still images play in PNG and other formats, and audio support ranges up to 5.1 channels.