From https://news.ycombinator.com/item?id=48404405 re: ffmpeg-webCLI https://github.com/tejaswigowda/ffmpeg-webCLI which is an ffmpeg PWA ;

> Objective metrics and tools for video encoding and source signal quality: netflix/vmaf, easyVmaf, psy-ex/metrics, ffmpeg-quality-metrics,

> [...] two UI wells A and B. In the "basic encoding" workflow, show in (A) the input video and audio waveform and metrics, and in (B) the output video and audio waveform and metrics.