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[mykillk]

Occasionally I find certain videos where the clock deviation is really high, like 15%. In Fullscreen Exclusive mode it causes a continuous stream of dropped frames, even if the rendering time is easily low enough to not be dropping any.

It only seems to happen with videos reported to have a 30.00 frame rate. Anyone have an idea what this is about?

[Jong]

Not an answer but some suggestions for diagnosis:

1. MadVR often starts out with a high clock deviation for me but then slowly converges on the right number over a long time. When this happens there are no frame drops/repeats. It seems like MadVR reads the wrong number at the start and just takes a long time for averaging to bring it back down (I keep meaning to report this in the MadVR Doom9 thread, this might finally push me to do it), but it doesn't affect playback. For me a pause/play fixes it. So, is the 15% stable or is it slowly ticking down? Does play/pause fix the deviation? If the deviation is fixed after play/pause do the dropped frames stop? It may be the two things are unrelated.

2. It would be useful to check the audio path when this happens.

3. A screenshot with the MadVR OSD would also be useful.

[mykillk]

1. For this video and the other ones I have a problem with, it usually starts around 17% and within a few seconds drops down to 15% and stabilizes there. It doesn't get any better.

2. Audio path is clean. Direct output with WASAPI Event Style

3.

4. Another common element seems to that they are in .flv containers

[Jong]

So no Videoclock (not that it should do 15% anyway).

[mykillk]

Nope, no Videoclock. My gpu / tv support all the refresh rates.

I'm almost positive the issue is actually at either the splitter or decoder level. I get glitchly playback on the file in VLC as well (but oddly with the audio, not the video for some reason). I've noticed that .flv files seem to have more problems than others. It's an awful container format I wish it would just go away.

[Jong]

Have you tried playing back in MPC-HC? Can you upload a sample?

Sounds like MC's audio renderer is freaking out somehow  ?

[mykillk]

I don't see why it would. It's typical mpeg audio format.

MC18 actually has glitchy video playback while VLC has glitchy audio playback. Both, I assume, would be the result of this 15% clock deviation.

[Jong]

Normally that clock deviation would mean MadVR thinks MC is speeding up the audio. but I guess it might be seeing something else if flv playback is just messed up. Madshi might chip in at some point.

Have you looked at it with MediaInfo? Anything interesting?

Have you tried with another video renderer? Does EVR work? Might be worth colecting a MadVR log and posting in the MadVR thread, especially if it happens in MPC-HC too.

[mykillk]

I just tried it in MPC-HC EVR and it's showing basically the same 15% clock deviation.

It's almost like the actual frame rate of the video is different than the 30.00 being reported to the splitter. darn lying .flv files  Smiley

[Jong]

One thing that is very odd about that screenshot, which might be unrelated but..., is the present time. Normally that is sub 1ms on a modern system.

Is it normally like that:
- for all video?
- just for these troubled videos?

..or was it just an anomaly, maybe caused by screen capture?

[Jong]

I just tried it in MPC-HC EVR and it's showing basically the same 15% clock deviation.

It's almost like the actual frame rate of the video is different than the 30.00 being reported to the splitter. darn lying .flv files  Smiley

Yeah, this might be unfixable, other than, maybe, repacking the video in another container. And I've no idea what tools can pull apart an flv!

I'm happy to see if I get the same here if you want to upload somewhere. It's always possible, if not likely(!), I might spot something.

[mykillk]

That was caused by disabling desktop composition in fullscreen mode. I usually run in fullscreen exclusive mode and forgot to turn that option off when disabling FSE mode so I could take this screenshot.

I just turned desktop composition back on, and my presentation time in fullscreen windowed dropped back down to sub 1 ms, but it made no difference to the clock deviation.

[mykillk]

Yeah, this might be unfixable, other than, maybe, repacking the video in another container. And I've no idea what tools can pull apart an flv!

I'm happy to see if I get the same here if you want to upload somewhere. It's always possible, if not likely(!), I might spot something.

I appreciate the offer, but it's a large file being a whole half of football

I can deal with it. For some reason it doesn't seem to drop nearly as many frames in fullscreen windowed (despite having the same clock deviation) so for these problematic files I'll just switch to that.

[Jong]

I just tried it in MPC-HC EVR and it's showing basically the same 15% clock deviation.

It's almost like the actual frame rate of the video is different than the 30.00 being reported to the splitter. darn lying .flv files  Smiley

Did you mean EVR here? Because how would you see the clock deviation in EVR? If you havent tried EVR in MPC-HC or MC I would. Have you tried using RO Std instead of HQ? Not even sure what ROHQ uses as a splitter for flv. Quite possibly LAV (I see it supports it). It might be worth trying to replace LAV with another splitter.

[mykillk]

Did you mean EVR here? Because how would you see the clock deviation in EVR? If you havent tried EVR in MPC-HC or MC I would. Have you tried using RO Std instead of HQ? Not even sure what ROHQ uses as a splitter for flv. Quite possibly LAV (I see it supports it). It might be worth trying to replace LAV with another splitter.

EVR on MPC-HC has a similar CTRL+J OSD as MadVR. In fact it has tons of info and pretty graphs! RO Standard seemed to have the same glitchy playback, but I couldn't tell for sure because it does not have an OSD. As for a different splitter, I'm pretty sure VLC does not use any of the LAV filters and it exhibited glitchy playback as well.

[Jong]

Ah yes, I remember. The custom presenter I think (and EVR sync in a different way). But I didn't remember it had the same "clock deviation" stat as MadVR.

[mykillk]

Ah yes, I remember. The custom presenter I think (and EVR sync in a different way). But I didn't remember it had the same "clock deviation" stat as MadVR.

It has a "clock" stat. So instead of a 15% clock deviation it shows me 115% clock

[Jong]

Still, try RO std (not sure what that uses for flv). And try without LAV as the splitter (if you can be bothered!   ).

[mykillk]

I tried setting Haali as the splitter (the only other option in MC18) but it ends up using LAV anyway. I don't think Haali even supports .flv

I also tried using the built in FLV splitter in mpc-hc and it would display the first frame of the video but nothing after that.

I think it's safe to say at this point that the problem is the video and it's .flv container!

[Jong]

Sounds about right!

[Trumpetguy]

 A long shot - do you have a sound card/DAC that you turn on/off manually? I do, and when it is switched off, I get the same deviation as you describe. This is because MC syncs video and audio, and misses the audio clock when the audio output device is turned off.

EDIT: I realize my question is rather daft, you wouldn't normally be watching anything with your audio switched off. It is just that I got this experience myself while setting up my htpc, video config and MC in general with my audio gear all off, and thought I'd mention it.