MediaRiffle v0.6.2

✨ Features and improvements

• Dolby Vision, and better HDR tone mapping with libplacebo: when the server's ffmpeg has libplacebo and a Vulkan
  GPU works (checked at start), converted HDR is tone-mapped with it on the GPU, applying Dolby Vision's metadata, and
  HDR10 looks more natural than with zscale. Dolby Vision profile 5 (streaming services, web rips), which has no
  ordinary picture underneath and showed dark and green or purple, is never sent as it is any more: it's converted.
  Profiles 7 and 8 still play as the HDR10 they carry. Transcoding:UseLibplacebo turns it off. See docs/configuration.md.

🐞 Bug fixes

• Dolby vision (!18) (@acalcutt)
• Auto quality settles down: it kept switching levels on files the server converts at only a little faster than
  they play (4K HDR, often). Waiting for ffmpeg to make a segment no longer counts as a slow connection, Auto no longer
  steps up to a level ffmpeg can't keep up with (it tries again after 10 minutes), steps up only with plenty of room,
  and stays on a level 20 s before stepping up from it. Safari's own player and a Chromecast pick levels as before.