• 1
  • 42
  • 43
  • 44(current)
  • 45
  • 46
  • 50
24p and audio sync issues
(2014-10-23, 21:43)Warner306 Wrote: Users continue to post their problems and hacks/solutions, but I am wondering if this issue is being addressed at the development level at all with the addition of new features.

Ally my requests for data and requests for testing have been ignored. Not much development can do then. My last attempt was http://forum.xbmc.org/showthread.php?tid...pid1773917, no response ....
Reply
I'll be happy to help any way I can.
Reply
I'd provide data if I had time. But I've become accustomed to using pixel shaders and different video renderers to the point that I no longer have any need for DVDPlayer. But despite some comments to the contrary, 24p sync issues do exist, and I have some skepticism that the Kodi team can do better than any other of the alternatives available on the Internet. None of them provide perfect sync, for me at least.

Reclock, and Video Clock (as cloned by JR River Media Center), as I've stated are the best audio renderers I've found. Something similar in Kodi would be nice.
Reply
For the record, my sync issues described here are fixed with the latest rev (compiled from bec2747 today). All file types now have identical A/V sync and sync doesn't change after rewinding or fast forwarding. My previous build - which still had the issue - was compiled Nov. 1 (don't remember the rev., though), so it must've been fixed quite recently.

I've tested only briefly with a handful of files using SW decoding and PS renderer only, will test more in the next couple of days using different streams/files/decoding/rendering. So far, it looks like this is fixed, though.
Reply
glad to hear that improvements show. thanks for feedback
Reply
This whole issue seems a lot better with Kodi, not quite perfect but almost. Anyone else finding this is the case?
Reply
……Actually, further use has revealed that the problem is still present. However something’s different because my previous offset of 160ms is too much with Kodi, and I’m while I’m yet to fine tune it, it would appear that 100ms is about right now.
Reply
What I've found is the 250 ms offset I had to use previously when set for 24 Hz refresh is what I also have to use now if I don't change refresh and leave it at 60 Hz. In other words, the problem remains unchanged with 24 Hz, but has also appeared for 60 Hz. So they've changed something, but not for the better.
Reply
Since I switched back to SW decoding and PS rendering I have no sync issues at all. At least no delay I sense. With DXVA rendering I have to use 125 ms at 24p.
Reply
1000 / 24 ~ 42

42 * 3 ~ 125

Do we have 3 render buffers somewhere in a queue? :-)
First decide what functions / features you expect from a system. Then decide for the hardware. Don't waste your money on crap.
Reply
I suspected this already, but could not find the extra buffers yet. Smile
Reply
Between version 13 and 14 I experienced no differences. Still - 250ms needed for me.
With 14.1 I now need - 350ms.

Maybe this helps someone?
Reply
Xophile, since the upgrade to 14.1 I am also noticing lipsync issues beyond those already expected. It seems to vary throughout the course of a movie/TV programme now whereas it was a stable offset before.
Reply
I've not been following this thread for a while, but I've done some testing anyways...

To me it seems that the lipsync issue is only related to v-sync. At least it is on my 3 different setups.

Disable V-sync in Windows = no issues with 24p.
Enable V-sync in Windows = massive issues.

Actually this is not that strange when you come from a world of gaming... V-sync is a gamers worst nightmare. Impossible to get correct sync between GPU output and monitor refresh rate resulting in lag.
Disable V-sync and you get tearing, but no lag.

Windows 8 cannot disable V-sync i think, but Windows 7 can. (By simply disabling aero-theme)

For those of you that's still having problems try this:

Disable V-sync in windows by using windows basic theme.
Sync playback to display -> Audio clock

Then check if you get better sync. You will get tearing on the menus and maybe if you playback 50/60hz material.
I also use Netflix etc on the same rig and I've solved this by creating a shortcut for disabling/enabling aero.
Netflix etc. will not get tearing as long as aero is enabled.
System: XBMC Gotham 13.1, HTPC: AMD 6450 1GB, Intel i5 3470S, 8GB DDR3, ASUS P8H61-M PRO, OCZ SSD Agility 3, NYXboard Hybrid Remote
Surround: NAD M15HD2, NAD M25, B&W 803 Diamond, B&W DB1, B&W HTM4, Pioneer KRP-600A / Panasonic 65VT50
Reply
I know this is an old (and ongoing) topic but I hope someone can give me some additional advice or information.

I've been struggling with 24p issues for a long time now and have been getting by with OpenElec and some manual delay adjustments in advancedsettings.xml. I recently changed AV receiver and decided to revisit this problem. Let me first start by saying that the new AV receiver, with identical HTPC and OpenElec settings, plays things exactly how they were before. I'm almost 100% certain that swapping out the amp (which I did because of its age) has made zero difference here. After a lot of testing, though, I've found that for some reason certain audio formats appear to have different delays associated with them.

If I use passthrough on AC3/Dolby Digital tracks, there is an apparent delay of somewhere around 175ms. This isn't exactly 175ms, but I can't seem to find the "perfect" value that seems to sync up perfectly. Nonetheless, if I disable passthrough and let Kodi decode the AC3 instead, there is no delay and everything is synchronised perfectly. What's odd about this is that DTS passthrough works flawlessly and perfectly in sync. Why does DTS passthrough have no sync problems but AC3/Dolby does? My amp supports it without any problems, and there are no differences in processing for each format.

Obviously I'd prefer my amp to handle the AC3 directly via passthrough, and I know for sure it's capable of handling AC3/Dolby Digital. I can't work out what is causing the delay. It's not my amplifier, as the same thing happens with the old amp. Is passthrough handled differently for different audio formats? Any ideas welcome.
Reply
  • 1
  • 42
  • 43
  • 44(current)
  • 45
  • 46
  • 50

Logout Mark Read Team Forum Stats Members Help
24p and audio sync issues8