subtitles disappear when seeking with subsdelay plugin
To reproduce:
- Invoke VLC like this:
/Applications/VLC.app/Contents/MacOS/VLC \
--sub-filter subsdelay --subsdelay-mode 0 --subsdelay-factor 4 --subsdelay-overlap 3 --subsdelay-min-alpha 100
- Open a video file with subtitles.
- Wait a while for several lines of subtitles to appear.
- Pause, then seek forwards and backwards (by pressing right arrow followed by left arrow).
Expected behavior
The same subtitles are visible after seeking forwards and backwards (up to 3 lines).
Actual behavior
Only at most one line of subtitles is visible after seeking.
Example 1 (all lines disappear):
Example 2 (all but one line disappears):
What's happening is that the subsdelay filter is not applied while seeking around, so only subtitles that were originally supposed to be onscreen are displayed. The subsdelay filter only takes effect when playing a video.
System info
VLC Version: Version 3.0.18 Vetinari (Apple Silicon) macOS version: 12.5
Notes
Also happens on latest VLC on Linux.