[Feature Request] Display Current FPS

[mattbisme]

Perhaps the most surprising missing feature is an FPS counter on running encodes. I often use FPS as a way to measure the practicality of an encode. Depending on the content, sometimes it's not worth using the "best quality" encode; it helps to know how much relative time I'll be saving based on the settings that I change.

Currently, I use a stopwatch to check how many "seconds per second" are being encoded. 🤣