MacBook Pro -> Samsung S90D HDMI stutter with almost no dropped frames

[diamat85]

I’m trying to diagnose a strange playback problem with an external TV.

My MacBook Pro is connected to a Samsung S90D OLED over HDMI. The same files play smoothly on the MacBook’s own display, but motion on the S90D looks uneven/stuttery. It can be fine for a while and then get worse after a few minutes. Restarting VLC sometimes clears it temporarily. I’ve also reproduced it in IINA.

VLC’s counters don’t look like a normal dropped-frame problem. With a 24.000 fps H.264 file (1424x1036), VLC showed 36,130 displayed frames, 2 lost frames and 0 lost audio buffers. I’ve tried 24/50/60 Hz output, HDR off, different TV motion settings, restarting the player, booting with the TV already connected, and avoiding HDMI audio. A 23.976 fps file and a 25 fps 10-bit HEVC file behave similarly. The TV is fully updated.

Has anyone seen this sort of frame-pacing/synchronisation issue with a Samsung OLED over HDMI? I’m wondering whether the problem is the Mac’s output timing, the HDMI path or the TV’s processing.

[Dalek]

It looks like this is a common issue for Macs in general when I searched 'macbook pro stutter tv'

1. Try a different HDMI cable

2. This comment mentions matching up the refresh rate on the Mac as the same as the TV: https://www.reddit.com/r/hometheater/co ... t/l488bdk/

For example, is your Mac at 120hz and the TV is at 60hz? make sure both the Mac display and the TV are at the same refresh rate.

3. https://www.avsforum.com/threads/hdmi-m ... y.1941473/ - "So basically plugin in as you want to have HDMI, etc, then reboot/shut-down your MBP and restart."

4. https://discussions.apple.com/thread/256063336 (OP mentions here that this has occurred for them on multiple macs)

5. Connect your HDMI cable to your mac, then restart the mac (that seems to have helped with audio issues as bizarre as that sounds, maybe it can help with the stutter too)

6. Mirror the screen instead of using the TV as a secondary display

Hope this helps.

[diamat85]

I saw that but I have copied the same films onto a USB stick and played them directly using the television's built-in media player, with no computer or HDMI connection involved at all, and the stutter appears....