smplayer cannot work with mpv correctly & cannot show ass properly with mplayer

[sgqy]

smplayer have 2 backends.

with mpv:

  Negative: It cannot get video position. I cannot scroll video or change volume.
  Positive: The ASS subtitle works fine.
  Positive: Screensaver is disabled successfully while playing a video.
  Info: This happened after a few days of ubuntu 20.04's appearing.

with mplayer:

  Negative: The ASS subtitle miss its style; lines with 0 seconds still be shown in a fixed time.
  Negative: Open a smplayer sub window or menu, the main window becomes black.

isolate mplayer:

  Positive: The ASS works fine with its style.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: smplayer 18.10.0~ds0-1
ProcVersionSignature: Ubuntu 5.3.0-24.26-generic 5.3.10
Uname: Linux 5.3.0-24-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu13
Architecture: amd64
Date: Sun Dec 8 19:01:50 2019
SourcePackage: smplayer
UpgradeStatus: No upgrade log present (probably fresh install)

[rvm (rvm)]

The problem with mpv was fixed in smplayer 19.10.2.