[RPi5] AC-3 audio stutters with HDR content

Hello LibreElec community!

I was wondering if anyone has ever had a problem that is driving me mad.

I'm using LibreElec on a new Raspberry Pi5, connected via HDMI to a HT Onkyo (5.1), which is connected in turn (via HDMI also) to a LG OLED.
Everything works fine, but if I play 4k H265, HDR, AC-3 (or E-AC3) content, 24 fps, I randomly get annoying audio stutters, video is fluent.

If I disable HDR, fix the refresh rate to something more than 24hz, or use a DTS source the problem disappears.
There isn't anything useful in the logfile, and with my "old" Celeron (similar H265 decoding features) the same files works flawlessy.

Any idea on what test I can do?

Thanks!

Quote from Da Flex

I guess the old Celeron doesn't provide HDR, right? Otherwise it would be interesting to compare working and non-working logs.

The "old" Celeron is not so old, it has HDR decoding capabilities. I'll post the logs soon.

I'm also buying new high-speed microHDMI-HDMI cable, but I'm pretty sure that it is not the cause of the problem (otherwise I think I would see it on DTS-HD decoding also).

Thanks for the reply.

I don't know why, but it seems like the problem has been fixed by changing the HDMI cable to a certified 2.1 one. The old one was brand new but it was 2.0 and apparently could not handle HDR at 24Hz.

Thanks anyway!

Marking thread as resolved.

Quote from Da Flex

I never heard about that. Thanks for reporting.

Believe me, I'm really puzzled too... maybe it was a shitty quality cable, but it gave me this issue only with these precise settings: HDR, 24hz, AC-3 audio.

Anyway, with the new cable everything's fine, I'm very happy.