: This is a TV series based on the "Dune" universe created by Frank Herbert. The series is a prequel to the events of the original "Dune" novel and explores the origins of the Bene Gesserit Sisterhood.
ffmpeg -i "Dune.Prophecy.S01E04.mkv" -c:v libvpx-vp9 -crf 34 -b:v 0 -c:a libopus -b:a 96k -movflags +faststart output_web.webm
: This refers to Season 1, Episode 4 of the series.
Libvpx is the reference encoder for VP8 and VP9. Use (not VP8) for high-quality episode encodes.
If you have the file, you can open it with a media player like VLC or MPV and press Ctrl+J (VLC) or check the statistics to see the decoder (libvpx) and the exact bitrate/resolution. You can also use a tool like MediaInfo to see if it is using VP9 Profile 0 or Profile 2 (HDR).