.ass subtitle doesn't render correctly when using hardware decoding

Description

.ass subtitle doesn't render correctly when using hardware decoding, sometimes you could barely see the subtitle because it's transparent and wash out. Software decoding renders .ass subtitle just fine.

Expected behavior

Actual behavior

Steps to reproduce

1. turn on hardware encoding
2. play video with .ass subtitle
3. see that it doesn't render correctly

Screenshot / video

software decoding

hardware decoding

Context

App version

Android version

Device model

App mode

Smartphone

TV

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