Severe stuttering (QoS dropped frames) when playing H.264 videos in Parole

Severe stuttering (QoS dropped frames) when playing H.264 videos in Parole, but not in mpv or gst-play-1.0 (VAAPI HW decode, AMD/Mesa, Xubuntu 24.10)

On my AMD-based Xubuntu 25.04 system with up-to-date Mesa and GStreamer, Parole stutters heavily (massive frame drops due to "QoS") when playing H.264 videos, despite hardware decoding working flawlessly in both mpv and gst-play-1.0. The problem appears to be specific to Parole’s GStreamer pipeline, not the underlying hardware or libraries.

I was using Parole 4.18 but decided to build 4.20 to solve the issue but no luck. I'll give my build command here just for reference: meson setup builddir
--prefix=/usr/local
-Dbuildtype=release
-Dc_args="-O3 -march=znver5 -fomit-frame-pointer -flto=auto"
-Dcpp_args="-O3 -march=znver5 -fomit-frame-pointer -flto=auto"

I shouldn't be dropping any frames on a TikTok video with an AMD 9950x CPU and an AMD RX 9070 behind it but I can see frames dropping. Doesn't happen on VLC.

• Video stutters throughout playback in Parole.
• Massive numbers of dropped frames (QoS warnings) in the logs.
• Audio underflows (Got underflow) are also seen.
• Hardware decoding is definitely being used (confirmed by and vainfo).
• No such stutter in mpv, gst-play-1.0, or even AV1 playback.

Parole Media Player 4.20.0

Thank you, Joel