https://forum.videohelp.com/ en Mon, 07 Sep 2026 21:19:40 GMT vBulletin 60 https://forum.videohelp.com/images/misc/rss.png https://forum.videohelp.com/ https://forum.videohelp.com/threads/421092-Open-benchmark-A-V-sync-%28lipsync%29-across-screen-HDMI-recorders?goto=newpost Sat, 05 Sep 2026 17:32:24 GMT Been digging into screen/HDMI recording internals for a while, and one thing that bugs me is how little anyone actually measures A/V sync drift instead of just eyeballing it. So I built a small diagnostic tool that reads the MP4 structurally (mdhd/elst edit-list boxes, etc.) and reports the real... Been digging into screen/HDMI recording internals for a while, and one thing that bugs me is how little anyone actually measures A/V sync drift instead of just eyeballing it.

So I built a small diagnostic tool that reads the MP4 structurally (mdhd/elst edit-list boxes, etc.) and reports the real audio/video offset in milliseconds — not "does it look synced," an actual number.

Ran it against Bandicam and EaseUS RecExperts on identical clips: residual offset landed anywhere from ~10ms to ~40ms, with no drift correction over time — the offset doesn't shrink, it just sits there (or slowly grows on longer files).

OBS is the interesting one. Officially it's a fine, capable recorder, but its own forums are full of threads reporting drift in the 0.5s–3s range on longer sessions — and this isn't some fringe capture-card edge case. Multiple threads describe it happening with plain USB webcams and USB mics, no exotic hardware involved. The root cause seems to be physics, not settings: your audio interface has its own internal clock, OBS timestamps frames off the system clock, and a typical ~50ppm clock mismatch alone adds up to roughly 0.18s of drift per hour — which is why short clips look perfect and 2-hour streams don't.

Haven't run numbers yet on Action! or ShadowPlay/ReLive — if anyone here uses those regularly, curious what your longer recordings look like.

Post your recorder + recording length and I'll run the file through the tool for a second opinion, or grab it yourself and check your own footage. Not claiming this is exhaustive — just tired of "trust me it's synced" being the default answer. ]]> Off topic andratek https://forum.videohelp.com/threads/421092-Open-benchmark-A-V-sync-%28lipsync%29-across-screen-HDMI-recorders https://forum.videohelp.com/threads/421082-Organism-in-my-Apple-Cider-Vinegar?goto=newpost Thu, 03 Sep 2026 11:03:09 GMT I'm aware of the mother and other beneficial bacterias/probiotics, I make my own kefir and yoghurt and stuff. But I've been using ACV for maybe 5+ years and I've never had anything like this inside it, is this cool or what?


[Attachment 93643 - Click to enlarge]

[Attachment 93644 - Click to enlarge]

[Attachment 93645 - Click to enlarge]

This thing looks like an aquatic creature or something, nothing like any pictures of the mother I see online and I've never had anything like it in my previous bottles. ]]> Off topic vidsrme https://forum.videohelp.com/threads/421082-Organism-in-my-Apple-Cider-Vinegar