playbin3: text-offset property has no effect, negative av-offset causes stuttering playback
Following observations:
- playbin text-offset with external subtitle files:
✅ - playbin3 text-offset with external subtitles files:
❌ (no effect) - playbin text-offset with in-container subtitles:
❌ (no effect) - playbin3 text-offset with in-container subtitles:
❌ (no effect) - playbin positive av-offset:
✅ - playbin3 positive av-offset:
✅ - playbin negative av-offset:
✅ - playbin3 negative av-offset:
❌ stutters (gst_base_sink_is_too_late()
triggers)